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Scooters - 125 to 300 => Super 8 150 => Topic started by: polishpipes10 on April 07, 2019, 11:34:06 PM
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Hi everyone,
I am new here and I am having a major problem finding TDC on my Super 8 150cc 2009. Any help or suggestions at all would be greatly appreciated.
Thank you
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You can just have a close look at the camshaft sprocket. It will have two small holes and two big holes between the center and outer edge of the sprocket.
When the piston is at TDC, the two smaller holes will be in line with the top of the cylinder head.
While the two smaller holes are in line with the cylinder head, you also need to have a good look at the position of the camshaft lobes. If the piston is at TDC, both camshaft lobes will be facing towards the REAR of the engine.
It the lobes are facing towards the front of the engine, it means the piston is NOT at TDC, and the crankshaft needs to be turned another 360 degrees - until the two smaller holes at the sprocket will be in line with the upper level of the cylinder head again.
Or, if you are a bit unsure about using the camshaft lobes as pointers:
- if the two smaller holes are in line with the upper level of the cylinder head, you can have a look at the timing marks at the Flywheel. If the piston is at TDC, the timing mark at the flywheel will be in line with the timing mark on the engine casing. If the timing mark on the flywheel does not line up with the timing mark on the casing - it means the engine needs to be turned another 360 degrees, until the two smaller holes at the camshaft sprocket gets in line with the upper level of the cylinder head again. The piston will then be at TDC, and the timing marks on the flywheel and engine casing will line up with each other.
You can also have a look at the video below . Don't worry if your scooter is not the same model as the scooter on the video. These scooter engines are similar to the GY6 engine copies, and the timing marks at the camshaft sprockets, flywheel, and engine casings are exactly the same.
https://www.youtube.com/watch?v=dLS5vLRaZgg (https://www.youtube.com/watch?v=dLS5vLRaZgg)
P.S. (There is no need to remove the carburetor - the video is just to show the holes at the camshaft sprockets, as well as the timing marks on the camshaft pulley and engine casing.)
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Also, if all is confusing - with the sprocket holes aligned, as above - you must be able to feel movement up & down when you take hold of the rocker arms. If no movement...do not proceed, you are not at TDC....rotate engine again, align sprocket holes, feel again for movement
Stig
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Also, if all is confusing - with the sprocket holes aligned, as above - you must be able to feel movement up & down when you take hold of the rocker arms. If no movement...do not proceed, you are not at TDC....rotate engine again, align sprocket holes, feel again for movement
Stig
Problem with that is that if the current valve clearance gaps are too small, there might be no play (no movement) at the rocker arms while the piston is indeed at TDC position.
Therefore it should be better not to use rocker arm movement as guideline.
I forgot to mention - when the engine gets turned to line up everything, the engine always needs to be turned clockwise (facing the cooling fan / flywheel side of the engine).
The reason being - if the engine gets turned anti-clockwise the chain slack at the “tensioner-shoe side†of the chain will prevent the timing marks from lining up 100% correctly.
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Problem with that is that if the current valve clearance gaps are too small, there might be no play (no movement) at the rocker arms while the piston is indeed at TDC position.
Therefore it should be better not to use rocker arm movement as guideline.
Point taken - but my final test before I proceed with loosening any lock nut is to test for rocker arm movement.
In 52 years of setting the valve lash on air cooled engines I have never found intake and exhaust valves to both be without movement when at TDC.
It is not the first step in the procedure - but it is always my final "proof".
Stig
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You can just have a close look at the camshaft sprocket. It will have two small holes and two big holes between the center and outer edge of the sprocket.
When the piston is at TDC, the two smaller holes will be in line with the top of the cylinder head.
While the two smaller holes are in line with the cylinder head, you also need to have a good look at the position of the camshaft lobes. If the piston is at TDC, both camshaft lobes will be facing towards the REAR of the engine.
It the lobes are facing towards the front of the engine, it means the piston is NOT at TDC, and the crankshaft needs to be turned another 360 degrees - until the two smaller holes at the sprocket will be in line with the upper level of the cylinder head again.
Or, if you are a bit unsure about using the camshaft lobes as pointers:
- if the two smaller holes are in line with the upper level of the cylinder head, you can have a look at the timing marks at the Flywheel. If the piston is at TDC, the timing mark at the flywheel will be in line with the timing mark on the engine casing. If the timing mark on the flywheel does not line up with the timing mark on the casing - it means the engine needs to be turned another 360 degrees, until the two smaller holes at the camshaft sprocket gets in line with the upper level of the cylinder head again. The piston will then be at TDC, and the timing marks on the flywheel and engine casing will line up with each other.
You can also have a look at the video below . Don't worry if your scooter is not the same model as the scooter on the video. These scooter engines are similar to the GY6 engine copies, and the timing marks at the camshaft sprockets, flywheel, and engine casings are exactly the same.
https://www.youtube.com/watch?v=dLS5vLRaZgg (https://www.youtube.com/watch?v=dLS5vLRaZgg)
P.S. (There is no need to remove the carburetor - the video is just to show the holes at the camshaft sprockets, as well as the timing marks on the camshaft pulley and engine casing.)
Thank you for the video link it was very helpful, however, my flywheel with the markings T and F are clearly visible. The problem I am having is I cannot find for the life of me the mark I am supposed to be lining the T up with. I have seen at least 4 different articles telling me 4 different places it should line up with, none of which have worked. One said to line it up in the center of the "V" on the casing. Another shows me an area on the casing that does not exist on mine. You get the point. I would like to avoid having to pull apart and reassemble everything each time I need to check if the mark is indeed lined up with the casing. I have been troubleshooting this for over a week now with no transportation and have missed work because of this. It is very late here, but I will attach a pic tomorrow of my flywheel and the casing that I have (which doesn't seem to match ANY other casing I have found in my research). Hopefully this is something really simple and I will been able to get this thing to turn over again and be on my way, but as of tonight, After lining up the marks on the camshaft and making sure the larger hole is away from engine (up), along with trying to find this mystery mark on the casing near the flywheel, all I get is the sound you get when you turn the key and try and start but it just keeps trying to start but justs keeps rolling the camshaft and the flywheel with no actual turn over of the motor starting. THIS HAS BECOME SO FRUSTRATING! I AM READY TO THROW IT OFF A BRIDGE! JK!!
So another quick question, if the timing is off, is that a reason why the engine will not actually start up? or could I have the timing right and maybe something else is causing the problem? Also when removing the cylinder head earlier this week, (which is the entire reason I began this repair because spark plug hole is stripped beyond repair) I notice a piece of a VERY strong magnet fall out of somewhere. Any idea what that might be and could that be causing my problem as well by any chance.
Thank you so much for your replies and I look forward to your next response.
Allan
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Thank you for the video link it was very helpful, however, my flywheel with the markings T and F are clearly visible. The problem I am having is I cannot find for the life of me the mark I am supposed to be lining the T up with. I have seen at least 4 different articles telling me 4 different places it should line up with, none of which have worked. One said to line it up in the center of the "V" on the casing. Another shows me an area on the casing that does not exist on mine. You get the point. I would like to avoid having to pull apart and reassemble everything each time I need to check if the mark is indeed lined up with the casing. I have been troubleshooting this for over a week now with no transportation and have missed work because of this. It is very late here, but I will attach a pic tomorrow of my flywheel and the casing that I have (which doesn't seem to match ANY other casing I have found in my research). Hopefully this is something really simple and I will been able to get this thing to turn over again and be on my way, but as of tonight, After lining up the marks on the camshaft and making sure the larger hole is away from engine (up), along with trying to find this mystery mark on the casing near the flywheel, all I get is the sound you get when you turn the key and try and start but it just keeps trying to start but justs keeps rolling the camshaft and the flywheel with no actual turn over of the motor starting. THIS HAS BECOME SO FRUSTRATING! I AM READY TO THROW IT OFF A BRIDGE! JK!!
So another quick question, if the timing is off, is that a reason why the engine will not actually start up? or could I have the timing right and maybe something else is causing the problem? Also when removing the cylinder head earlier this week, (which is the entire reason I began this repair because spark plug hole is stripped beyond repair) I notice a piece of a VERY strong magnet fall out of somewhere. Any idea what that might be and could that be causing my problem as well by any chance.
Thank you so much for your replies and I look forward to your next response.
Allan
Sorry to hear about your misfortune.
Firstly, I only now realize that the cylinder head has been removed, the Camshaft and camshaft have been removed, and the timing chain has been separated from the camshaft sprocket.
In short - in cases like this there is no "short cut" to line everything up correctly. As a "starting point", unfortunately you need to find that "missing" aligning mark somewhere at the casing, or wherever it might be. Otherwise you can easily be running in circles for a long period.
Rather ignore my initial suggestion to have a close look at the position of the cam lobes, because that's just an easy way to check whether the piston is at TDC when all timing marks have been lined up correctly PREVIOUSLY.
In this case the engines timing could easily be WAY off - simply because the timing marks at the crankshaft Pulley and engine Casing (or wherever) have not be lined up correctly initially. If fact - your engine's timing could easily be off as far as 180 degrees at the camshaft , while the pulley is indeed at TDC.
So the answer is yes, in your case incorrect timing is most probably the reason why the scooter doesn't start.
Unfortunately I never worked on a scooter like yours - so I have no idea where the alignment mark you're looking for is suppose to be. Hopefully somebody else will be able to help ? Also forward some close photos, it might give us an idea.
I have no idea where the magnet was coming from. A close photo might help to point us in the right direction as well.
Good luck, I hope to see some photos soon.
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(https://i.postimg.cc/mrmWjJ84/0.jpg)
(https://i.postimg.cc/ZR9YdJZ2/0000.jpg)
(https://i.postimg.cc/Bvbm9nxj/00000.jpg)
If your scoot agrees with photos 2 and 3 - you are at TDC. (unless some one has been there before you, and really screwed things up)
If you can see as in photo #1 - that's a bonus! the 'line' and the 'T' will be next to the 'V' in the engine case. Often, really hard to see even with flash light.
OK, this will get you able to do a valve clearance check....but, sadly I think you have more issues than the valves. You might need to start looking for other transportation!
I hope I am wrong. Truly. I know what it's like to be without transportation.
Also, there is no magnet in a scooter cylinder head cover. If it fell out of the cylinder head cover when you removed it - it was likely ingested by the engine. Perhaps it fell 'off of' the cylinder head exterior?
Is it a small barrel shaped magnet - possibly come adrift from an oil drain plug?
Stig
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Just to explain my previous post - in the last paragraph of polishpipe10's previous post, he mentioned that the cylinder head has been removed from the engine.
Now, on an engine with overhead camshaft there is now way how any given cylinder head can be removed, without removing the timing chain from the camshaft sprocket.
Which means (in this case) the timing chain was hooked back on the camshaft during re-assembling (after the cylinder head was back in place) . Therefore the camshaft sprocket has most probably not been hooked to the chain correctly .
@ polishpipe10
I think the 3rd photo (above, "must feel up and down movement") should not be used to determine whether the piston is at TDC or not - simply because the correct timing marks have clearly not been used to hook the camshaft sprocket back on the chain during re-assembling. Chances are very good that you will not find any movement anyway.
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(https://i.postimg.cc/mrmWjJ84/0.jpg)
(https://i.postimg.cc/ZR9YdJZ2/0000.jpg)
(https://i.postimg.cc/Bvbm9nxj/00000.jpg)
If your scoot agrees with photos 2 and 3 - you are at TDC. (unless some one has been there before you, and really screwed things up)
If you can see as in photo #1 - that's a bonus! the 'line' and the 'T' will be next to the 'V' in the engine case. Often, really hard to see even with flash light.
OK, this will get you able to do a valve clearance check....but, sadly I think you have more issues than the valves. You might need to start looking for other transportation!
I hope I am wrong. Truly. I know what it's like to be without transportation.
Also, there is no magnet in a scooter cylinder head cover. If it fell out of the cylinder head cover when you removed it - it was likely ingested by the engine. Perhaps it fell 'off of' the cylinder head exterior?
Is it a small barrel shaped magnet - possibly come adrift from an oil drain plug?
Stig
Good morning, here are the pics of what I see if I align the T onto the V on the casing. Looks Like it's correct to me, or am I wrong?
One thing I did notice however is that the rocker heads have zero play. They will not move at all?
Another question I have is, is putting the exhaust pipe back on a necessity when trying to see if it will start? Cause I have NOT been doing that because it is such a pain my a**! I just assumed that if it did start without exhaust pipe it would just be hella loud. Is that causing any trouble by not putting it back on before trying to start?
Also I attached the piece of magnet that I found. I'm pretty sure it did not fall out of the case. It looks to me as if it might be one of the magnets from the inside of the flywheel perhaps. Would that make it not start if one of those fell off?
Thanks again for taking time out to help me with this annoying and time consuming problem. I greatly appreciate your knowledge and expertise.
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Good morning, here are the pics of what I see if I align the T onto the V on the casing. Looks Like it's correct to me, or am I wrong?
One thing I did notice however is that the rocker heads have zero play. They will not move at all?
Another question I have is, is putting the exhaust pipe back on a necessity when trying to see if it will start? Cause I have NOT been doing that because it is such a pain my a**! I just assumed that if it did start without exhaust pipe it would just be hella loud. Is that causing any trouble by not putting it back on before trying to start?
Also I attached the piece of magnet that I found. I'm pretty sure it did not fall out of the case. It looks to me as if it might be one of the magnets from the inside of the flywheel perhaps. Would that make it not start if one of those fell off?
Thanks again for taking time out to help me with this annoying and time consuming problem. I greatly appreciate your knowledge and expertise.
Don't worry, I think your first two photos are a good indication that you will be able to get the engine running soon.
1. Firstly, The ""V" at the casing on your photo looks like the correct mark when the piston would be at TDC position.
2. Secondly, the two smaller holes at the camshaft Sprocket (2nd photo) is lining up with the upper level of the cylinder head, but there is a MAJOR problem - the big hole at the camshaft sprocket is not visible, and is currently located at the opposite side of where it is suppose to be seen while the "T" mark is at the position, indicated at your 1st photo.
To my mind this means chances are about 100% that the scooter's timing is 180 degrees off at the moment. This obviously happened when the Camshaft has been put back in place after the cylinder head has been removed.
Don't feel bad about this, I've made the same mistakes, and only learned the hard way.
This is what I would do:
1. Make sure the "T" mark at the pulley is in line with the "V" at the casing (like indicated at your 1st photo).
2. Loosen and remove the Crankshaft- and crankshaft Sprocket-combination completely, and turn the crankshaft 180 degrees, until the big hole at the crankshaft Sprocket is located at a 90 degree posission with the upper level of the cylinder head. (Remember to keep an eye on the "T" and "V" aligning marks (point 1 above) at the same time - because those marks need to line up correctly when the big hole at the Camshaft pulley is clearly visable, and located at a 90 degree position with the upper level at the cylinder head).
Sorry about the weird description - my first language is not English.
Don't worry about the exhaust - when everything has been lined up correctly, the engine should fire up perfectly without an exhaust.
The only thing that worries me, is the loose magnet. I have no idea where it came from. Maybe you should rather contact a dealer, and try to talk to one of their mechanics ?
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OK, cool yes I see how that would be a major problem so I am going to go and do that now and I’ll get back to you and tell you what my results are thank you again .
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Hang on a second! Cam turns at one-half speed of crank, right? Turn the crank one more revolution and the holes in the cam gear should be right, right? Confirm this before doing anything else, please.
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Hang on a second! Cam turns at one-half speed of crank, right? Turn the crank one more revolution and the holes in the cam gear should be right, right? Confirm this before doing anything else, please.
100 % correct. That’s the exact reason why I advised him to turn the crankshaft only 180 degrees, and NOT 360 degrees. (Should he turn the Crank Shaft 360 degrees while the “T†and “V†marks line up, the Crank Shaft would end up at the very same, INCORRECT position)
@polishpipes10
I almost forgot - while you are lining up everything correctly, I think it would make sense to hook the scooter’s battery to a battery charger in the meanwhile. Due to all the engine cranking while you were trying to start the engine, the battery Voltage might be too low to start the engine at this stage. The reason being - if your scooter has a DC CDI and the Power supply to the CDI is less than about 9.5 Volt at this stage, the engine could easily not start, simply because the power supply to the CDI would be too low to create a spark at the spark plug, and to start the engine.
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Gotcha, scooterfan! No, not "a gotcha!" but I roger what you are saying! That is, I think I understand.....crank revolves once (360 deg), cam revolves 1/2. Yep. That's right. The "T" shows up every revolution of the crank but the cam makes only a half-turn. So if he were to turn his crank one more turn from his picture, then his cam ought to look like Stig's except not as shiny! (Nobody's cam is as shiny as Stig's!)
I agree about charging the battery while we do all this!
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WAIT!!
We're advising too much info....some of which is incorrect.
He needs ONLY to rotate the engine forward again until: #1 his timing marks line up again, #2 the two lines on the sprocket line up, #3 the big sprocket hole is like my photos AND #4 THERE IS MOVEMENT IN THE ROCKER ARMS! Period!
Do not Loosen and remove the Crankshaft- and crankshaft Sprocket-combination completely, and turn the crankshaft 180 degrees !! Do not loosen anything. Just rotate the engine.
Rotate the engine as many times as you need to - until your marks & 3 holes are correct AND you have that rocker arm movement. Keep rotating until you have all 3. Do not remove or loosen anything......you're almost there! If you'd had that 3rd hole up there - you're rocker arms would have had movement!
Stig
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What Stig said! What Stig said!
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100 % correct. That’s the exact reason why I advised him to turn the crankshaft only 180 degrees, and NOT 360 degrees. (Should he turn the Crank Shaft 360 degrees while the “T†and “V†marks line up, the Crank Shaft would end up at the very same, INCORRECT position)
@polishpipes10
I almost forgot - while you are lining up everything correctly, I think it would make sense to hook the scooter’s battery to a battery charger in the meanwhile. Due to all the engine cranking while you were trying to start the engine, the battery Voltage might be too low to start the engine at this stage. The reason being - if your scooter has a DC CDI and the Power supply to the CDI is less than about 9.5 Volt at this stage, the engine could easily not start, simply because the power supply to the CDI would be too low to create a spark at the spark plug, and to start the engine.
OK, I have aligned the two lines with the case and the big hole is up, and the T is lined up with the V on the crankcase..............I have also been charging my battery daily. Because of this dilemma it drains the battery after about 6 times of trying to crank the engine.
Now the results.................................Nothing changed, it's still turning and turning and NOTHING. I tried starting it again and again until the battery could no longer do anything.
As to what you were saying about the crankshaft and turning it 180 degrees or 360 degrees. That has me a little confused.
Another thing and the reason why I am so confused about most of this is because I have read opposing instructions before I found you guys. For example, another persons video said , ALWAYS turn the flywheel COUNTERCLOCK WISE? You said CLOCKWISE?
So are you telling me that if I have the 2 smaller punch out holes aligned with the case, AND have the big punch out hole pointing up AND if the T on the flywheel lines up with the V on the case, that this still could be wrong if I turned the camshaft too far or too little even though everything lines up?
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OK, I have aligned the two lines with the case and the big hole is up, and the T is lined up with the V on the crankcase..............I have also been charging my battery daily. Because of this dilemma it drains the battery after about 6 times of trying to crank the engine.
Now the results.................................Nothing changed, it's still turning and turning and NOTHING. I tried starting it again and again until the battery could no longer do anything.
As to what you were saying about the crankshaft and turning it 180 degrees or 360 degrees. That has me a little confused.
Another thing and the reason why I am so confused about most of this is because I have read opposing instructions before I found you guys. For example, another persons video said , ALWAYS turn the flywheel COUNTERCLOCK WISE? You said CLOCKWISE?
So are you telling me that if I have the 2 smaller punch out holes aligned with the case, AND have the big punch out hole pointing up AND if the T on the flywheel lines up with the V on the case, that this still could be wrong if I turned the camshaft too far or too little even though everything lines up?
Sorry about this late reply ! It’s now 3 AM at this side of the pond and I actually went to sleep since my previous post. Maybe my guardian Angle became aware of Stig and Crossbolts comments, and decided to worn me that they don’t understand correctly !
Firstly, the Crankshaft ALWAYS need to crank clockwise. Remember, when the engine starts, it turns clockwise anyway ! Also remember - when the crankshaft turns clockwise, the Camshaft will turn anti-clockwise on any given engine. Maybe your other advisors just got confused !
I suggest at this stage you just leave the crankshaft as is, remove the spark plug, ground the spark plug to the engine - and see if you have spark at the plug when you swing the engine.
If you don’t have spark, it might have something to do with that loose magnet inside the engine. I suggest you contact a mechanic - that magnet could be part of the pick-up at the Crankshaft !
Good luck, I’m going back to sleep now !
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Which way to turn? My Piaggio turns counterclockwise because the nut to turn is on the left CVT side of the scooter. If you're using a turning point on the exhaust side of the scooter - turn clockwise.
You have things lined up nicely now - but you did not mention if you found movement in the rocker arms.
If not, do not proceed - keep rotating until you do.
OK, all lined up & correct small up/down movement in the rocker arms - yes?
"How to find TDC?" ….we have just answered your original question.
NOW of course you must check the valve gap using the correct thickness feeler blade. When the valve gap is correct, you should try starting the engine. Obviously if you just find TDC and do not check the valve gap - you have skipped the reason for finding TDC.
Hard starting points to a valve setting which has drifted away from ideal.
Once you find TDC and check that the valve gap is correct - you will have eliminated one common cause for hard starting.
What to do after finding TDC....
https://www.youtube.com/watch?v=eipDXgGdh6o (https://www.youtube.com/watch?v=eipDXgGdh6o)
Stig
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Which way to turn? My Piaggio turns counterclockwise because the nut to turn is on the left CVT side of the scooter. If you're using a turning point on the exhaust side of the scooter - turn clockwise.
You have things lined up nicely now - but you did not mention if you found movement in the rocker arms.
If not, do not proceed - keep rotating until you do.
OK, all lined up & correct small up/down movement in the rocker arms - yes?
"How to find TDC?" ….we have just answered your original question.
NOW of course you must check the valve gap using the correct thickness feeler blade. When the valve gap is correct, you should try starting the engine. Obviously if you just find TDC and do not check the valve gap - you have skipped the reason for finding TDC.
Hard starting points to a valve setting which has drifted away from ideal.
Once you find TDC and check that the valve gap is correct - you will have eliminated one common cause for hard starting.
What to do after finding TDC....
https://www.youtube.com/watch?v=eipDXgGdh6o (https://www.youtube.com/watch?v=eipDXgGdh6o)
Stig
Stig, you can open the CVT box and turn the CVT nut on any scooter out there, but the actual nut to turn the engine is actually located at the opposite side of the scooter engine - the nut at the centre of the FLYWHEEL , where the cooling fins are located (exhaust side of the engine).
Most engines on this planet turns clockwise. Apparently some Honda car engines and boat engines came with anti-clockwise engines, but that's all, I never saw any of those engines before. Apparently the boats with two engines came with one engine running clockwise, and the other engine anti clockwise - the idea behind this was to run the propellers in opposite directions.
One way to determine engine turning direction, is to judge turning from the OPPOSITE side of the gearbox. For example - on cars, trucks, etc. , you will see that when the engine is running and you have a look at the rotation direction of the fan belt pulleys - you will see those pulleys are turning CLOCKWISE. This obviously means the engine turns clockwise.
On scooters you need to judge engine rotation from the opposite side of the gearbox as well. In other words, if you have a close look at engine rotation from the opposite side of the gearbox (at the flywheel / cooling fins - while the engine is running) you will see the engine is turning CLOCKWISE. This obviously means the engine turns clockwise as well.
I had a look at images of your Piaggio scooter - and the gearbox is located at the same side as gearboxes on Kymco scooters. Engine rotation on your Piagio scooter is clockwise as well - just like on Kymco engines !
I must admit - I do not agree about the "feel for rocker movement" to determine TDC in this case, for the following reasons:
1. To remove the cylinder head, the timing chain had to be removed / seperated from the Camshaft, and Camshaft sprocket. (There is no other way to remove the cylinder head).
2. When the timing Chain has been hooked to the Sprocket during re-assembing, the camshaft Lobes were facing the WRONG direction. (IMPORTANT - Polishpipes10 initially clearly indicated that whatever he did, the "T' and the "V" marks, as well as the big hole at the sprocket dit NOT line up correctly.)
So
At that stage it would NOT make sense to feel for play at the rockers - because the cam lobes were facing the wrong direction.
3.Since Polishpipes re-alighned the camshaft Sprocket by alighning the "T" and "V' marks first, he actually proved that the camshaft lobes were off by 180 degrees, or more or less 180 degrees. (There is no way in life how he could "correct" such an incorrect alighment, just by keeping on turning the engine. Fact is, when the alighnment is out by 180 degrees, there in no way in life how the "T", the "V", and the big hole at the Sprocket will line up correctly).
4. Even since Polishpipes10 corrected the Camshaft's (and camshaft Lobe-) position, we do not know whether the valve clearance settings were correct BEFORE this work has been undertaken. We do not even know whether the Rockers were removed during this period. Therefore my point - I am not sure whether the "feel for play"method would be advisable in this case.
Please don't get me wrong. I am NOT trying to be the "wiser guy". All I know, giving advice at Forums is often quite complicated. People who ask questions often do not supply all needed information to get the right advice. To my mind people who ask questions at Forums plays a major role in keeping forums alive, and we need to do whatever we need to do to keep them mobile.
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...........................….So if he were to turn his crank one more turn from his picture, then his cam ought to look like Stig's except not as shiny! (Nobody's cam is as shiny as Stig's!)
Sorry Crossbolt - it looks like you only got me "halfway"!
The first part of your comment is 100% correct - but my understanding of what you mean by the quoted part (above) is that you might still be missing something.
Firstly - you need to understand that once the Camshaft timing is off by 180 degrees (or any given degrees), the timing can NEVER be corrected by just turning the crankshaft. For example - should the timing be off by 180 degrees, you can turn the crankshaft a zillion times or more, but correct timing will STILL be off by 180 degrees !
The reason is very simple - if the timing marks are off by (i.e) 180 degrees, the camshaft lobes will always be facing the wrong direction when the piston's is suppose to be at "compression stroke".
This means whatever you do, the camshaft lobes will ALWAYS be at the wrong position when the spark plug is suppose to ignite the fuel mixture at the correct moment !
The only way to get the time settings correctly - is to use the marks on the Flywheel and engine Casing as a "starting point", and then to make sure the timing marks on the camshaft Sprocket line up correctly AFTER THE CHAIN HAS BEEN HOOKED TO THE SPROCKET.
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(https://i.postimg.cc/pVjtMJHt/0belt.jpg)
Remove fan cover 3 screws on this Piaggio, Turn this nut counter-clock-wise to TDC.
Whole lot harder on the flip side.
Stig
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Hi polishpipes10,
Did you see a spark at the spark plug during a test ?
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Hi polishpipes10,
Did you see a spark at the spark plug during a test ?
Good morning, Yes I did see a spark after test! But still no luck.
I have another question, I where can i find a cylinder head that is the size of the one pictured on the LEFT? That is the one I need and i cannot find it anywhere for the life of me, everywhere only seems to have the "shorter" one on the right? I think the previous owner may have installed a big bore kit, but not sure how to tell. Any tricks as to how to tell if the engine has been upgraded with a Big Bore Kit?
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I assume the cylinder head has been removed from the engine at this stage ? If not, and the "incorrect" cylinder head is still mounted on the engine at this stage, I would do a compression test on the engine fist, just to confirm whether the engine do have compression or not.
If you do find proper compression, you should be able to start the engine. I would only be concerned about the cylinder head once a compression test indeed confirms that the cylinder head can not be used.
Just two questions:
Have you been able to start the engine when you bought this scooter ?
If not - are you sure the carburetor jets are not clogged up, and you are not having a fuel supply problem at this stage ?
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@ polishpipes10
Just another thought - I just had another look at your previous comments, as well as the attached photo, and I think you might have another major problem :
You mentioned that the "taller" cylinder head is the correct cylinder head, and to my understanding the "shorter" cylinder head (at the right on the photo) is shorter in height.
To my mind this can quite easily cause a major problem - because if you install the "shorter" cylinder head, the original timing chain will be too long, and should not be used when the shorter cylinder head gets installed.
The reason being - when the shorter cylinder head gets installed, the chain will be too long for this application, and the tensioner guide / slider would easily become far less effective. In fact, when the original chain get used on the shorter cylinder head - I think the sprockets will constantly jump some teeth at the chain.
Therefore - unless you are able to find a timing chain with the correct length, you should rather not use the "shorter" cylinder head.
Another thought:
I just had a look at images of timing chain guides and slides on Kymco scooter. (see picture below).
I am not sure whether the chain guides on these scooters have magnets, but if you have a look at the photo (below) you will see that the chain guide come with some sort of attachment.
I am not sure whether that attachment could hold a magnet ?
I was just thinking - while the original timing chain would be too long, and would probably be slapping like hell when you tried to start the engine - maybe that attachment came loose, and maybe that attachment was holding the magnet you discovered when you opened the engine ?
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I have question regarding this. Im afraid of messing up the TDC as the mark on the flywheel is not enough if I understand it correctly. The T mark can be aligned but you can still not be TDC on the compression stroke. How can I track this or be sure im at true TDC. in other words does the crank shaft rotate evenly because just in his case he had aligned the T mark but not at the TDC when you look at the camshaft. without the camshaft does it matter if the T is in the same position or if i rotate 360 degrees line the T mark again it wont make a difference?
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I have question regarding this. Im afraid of messing up the TDC as the mark on the flywheel is not enough if I understand it correctly. The T mark can be aligned but you can still not be TDC on the compression stroke. How can I track this or be sure im at true TDC. in other words does the crank shaft rotate evenly because just in his case he had aligned the T mark but not at the TDC when you look at the camshaft. without the camshaft does it matter if the T is in the same position or if i rotate 360 degrees line the T mark again it wont make a difference?
It IS easy to get flustered here.
Try this:
if T is in correct position
and
sprocket looks like the photo
and
there is slight (tiny!) up>down play on both of the rocker arms
you are at TDC - unless someone has been there before you to mess things up!
Let us know if you do NOT feel that small movement at the rocker arm ends.
Stig
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Good morning, here are the pics of what I see if I align the T onto the V on the casing. Looks Like it's correct to me, or am I wrong?
One thing I did notice however is that the rocker heads have zero play. They will not move at all?
Another question I have is, is putting the exhaust pipe back on a necessity when trying to see if it will start? Cause I have NOT been doing that because it is such a pain my a**! I just assumed that if it did start without exhaust pipe it would just be hella loud. Is that causing any trouble by not putting it back on before trying to start?
Also I attached the piece of magnet that I found. I'm pretty sure it did not fall out of the case. It looks to me as if it might be one of the magnets from the inside of the flywheel perhaps. Would that make it not start if one of those fell off?
Thanks again for taking time out to help me with this annoying and time consuming problem. I greatly appreciate your knowledge and expertise.
any update, V to the T mark or?