KymcoForum.com
Scooters - 50cc => Super 8 => Topic started by: RookieRecurve on December 11, 2014, 11:19:02 PM
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Hi all, new to the forum. I have been creeping in the background for a day or two, and have not come across any information pertaining to ignition. Does anyone have any experience with an upgraded ignition coil/wire/plug? I know that doing this upgrade will not likely result in any 'seat of the pants' feel, but I do expect that it will result in a smoother idle, and easier starting. I have done this upgrade on a truck one (MSD) and was impressed with the improvement.
This is the only manufacturer that I can find.
Thoughts?
http://www.ebay.ie/itm/Kymco-Super-8-50cc-2T-High-Performance-Racing-2-Pin-HT-Lead-Coil-/300958816419 (http://www.ebay.ie/itm/Kymco-Super-8-50cc-2T-High-Performance-Racing-2-Pin-HT-Lead-Coil-/300958816419)
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Those are fine. You can find much better pricing tho. They usually sell for 8-10 bucks in the US or 2-3 in Asia (Ali-Baba).
HPI Make's a rocket ship set up that can start anything... http://www.hpi.be/index.php (http://www.hpi.be/index.php)
For the spark Denso or NGK Iridium.
Welcome aboard!
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upgraded ignition coil/wire/plug
ScrappyDog Red Hot (http://www.scrappydogscooters.com/125_150cc_Performance.html) coil test video (https://youtu.be/p63JXW29tVo?t=14s) . . plug cap replacement video (https://youtu.be/4s0WHJTOReQ?t=1m57s).
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Imho those "racing" coils are garbage. They are cheap and of less quality than the OEM Kymco part. You won't notice a difference and it'll wear out faster than the OEM.
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I see a lot of this refers to four stroke engines, but the results would no doubt be similar. A timing advance seems to be the ticket for anything ignition related. Thanks all for the input!
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I see a lot of this refers to four stroke engines, but the results would no doubt be similar. A timing advance seems to be the ticket for anything ignition related. Thanks all for the input!
In this case you don't need to buy anything. Just dremel the slots the pickup coil is bolted with, and move it counterclockwise scoot 1/16" . I've also seen offset flywheel key, but idk if I would trust that. Advance in the ignition won't = power by itself.
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I sheared two of the off set keys. The only way to avoid it is to burnish the crank/flywheel to develop a perfect match.
Same goes for the HPI inner rotor kit. That doesn't even use a key. It depends on a perfect fit on the taper.
If you go for rotating the pick up... 2mm is all you want to go. I melted an intake valve at 2.5mm, and an exhaust valve at 3mm. 2mm is the sweet spot. I believe that equals 25-28^ initial, and a REAL 7-8^ at 10k rpm that is normally 0^. Up jetting is required to cool the intake valve.
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I sheared two of the off set keys. The only way to avoid it is to burnish the crank/flywheel to develop a perfect match.
Same goes for the HPI inner rotor kit. That doesn't even use a key. It depends on a perfect fit on the taper.
If you go for rotating the pick up... 2mm is all you want to go. I melted an intake valve at 2.5mm, and an exhaust valve at 3mm. 2mm is the sweet spot. I believe that equals 25-28^ initial, and a REAL 7-8^ at 10k rpm that is normally 0^. Up jetting is required to cool the intake valve.
Man, that's what I was thinkin' too! This is great stuff (what is this, Latin?) pass the cheese? (I cut 3/8" out of the middle of my plug/coil wire, and still couldn't kick-start my LIKE200i)
Stig
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;)You have to be somewhat mechanically inclined to understand this stuff. A 3/8" mid run splice is a delicate procedure best left to idioy... or is it idiots. Latin class sucked. :-*
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In this case you don't need to buy anything. Just dremel the slots the pickup coil is bolted with, and move it counterclockwise scoot 1/16" . I've also seen offset flywheel key, but idk if I would trust that. Advance in the ignition won't = power by itself.
While all instances are different, this guys results suggest otherwise.
https://www.youtube.com/watch?v=3d8qHNNi5CA&list=PLD60FEB66F10B4BD6&index=10 (https://www.youtube.com/watch?v=3d8qHNNi5CA&list=PLD60FEB66F10B4BD6&index=10)
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That's a good demo, I'd have to see dyno results to know if there was actually more power produced.
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I would have to say that in this example, with this bike, in those circumstances, a timing advance did in fact create more power. I would give 'real world' application the same merit as a dyno in this situation. If you follow this guy, he does follows a fairly rigid and thorough method of testing. While a timing advance may not create more power in all circumstances, it is not reasonable to say that advancing timing does not create more power on its own. In this instance, it would appear that it did. As far as power adders go, there are bigger gains to be had, but it is also worth noting that this is essentially 'free' power. That in itself might just be reason enough to give it a go!
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Timing does create HP. The reason is the combustion pressure goes higher. (not the ratio). Capturing the pressure at exactly the right piont in the rotation is the entire point of setting the Ign. timing.
One issue (I may be wrong...) He was advancing the stator. That only controls the point at which the CDI charges (prepares for firing). The Pulsar coil is the firring trigger. If you want to change when/where the spark is fired you have to advance the pulsar coil, AND the stator.
This part is so Stig can understand...
Morbi id efficit HP. Cuius ratio est, inflammatio pressura superiorem. (non ratio). Pressio piont adprehendit diligenter oportet ponere in ratione totius orbem provoco. sincere.
Constitutionis (... ut fallar) illo, stator. Quod autem ad hoc perveniant quod moderatur solum sumptus CDI (praeparat accendi). The Pulsar coil est firring trigger. Si vis mutat quando / ubi ignis accenditur habes progredi pulsar spiram et Stator.
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Timing does create HP. The reason is the combustion pressure goes higher. (not the ratio). Capturing the pressure at exactly the right piont in the rotation is the entire point of setting the Ign. timing.
One issue (I may be wrong...) He was advancing the stator. That only controls the point at which the CDI charges (prepares for firing). The Pulsar coil is the firring trigger. If you want to change when/where the spark is fired you have to advance the pulsar coil, AND the stator.
That makes sense, i was under the impression it just allowed the motor to work better at higher rpm allowing the scooter to max out right. On the zuma/minarelli engine the pulser coil moves with the stator plate, unlike gy6 and kymco where the pulser coil is bolted to the engine case.
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Ok. That too makes sense. I did not see the pulsar was mounted to the stator plate on the Mina type engine.
I messed around a LOT w/ timing curves in the ZX. Both having Sutai program an OEM cdi, and programing my own in the HPI cdi.
There is something just like the air/fuel ratio that applies to Ign. timing. Unfortunately I forget the formula.
It is based on flame front travel/A/F ratio/compression ratio, and compression pressure.
These all combine to create the Exhuast gas Temp. so the reason I forgot the formula is I have been using an exhaust gas temp gauge (on my 2t)
Something like if the timing is too far retarded, all the heat, and the expanding gasses dump into the pipe, and power is wasted.
If timing is too far advanced all the heat is kept in the cylinder, and the expanding gasses actually slow down the rotation.
Imagine spinning a ten ton wheel with a hand crank. At first you need to apply power all thru the revolution. That can be related to advanced timing.
As the wheel gains momentum, you only need to apply power toward part of the revolution, allowing momentum to continue the cycle.
That's why timing curves start out w/ more advance. The power needs to start sooner. As the rpm increases you retard the timing so as not to interfere w/ the momentum. Just a little "kick" at the top of the cycle is all that is needed to maintain,BUT you still need to allow for the flame front to expand Inside the cylinder or that spark cycle is wasted, and the power dumps.
Something like that...
Customer ready engines are tuned to run well thru all conditions that can reasonably be expected. Therefore they are "mildly" timed. All of our scooters will respond Very well to re-programing the Ign curves to suit our style/needs.
In Kymcos' the only option is changing the advance. Nothing can be done about the curve UNLESS you contact Sutai. They will program any curve you want (NO WARRANTY) in a custom cdi.
Unfortunately there is no way to know how your bike will respond except for trial, and error.
That's where after-market Ign systems shine. It's too bad most people don't want to plop down 5-600.00 bucks to try them.
In the long run a custom timing curve will save money on fuel, and engine life. Not too many see this aspect.
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Great info guys! Here is a cool video showing a timing advance trick on a Tao Tao. I am not sure if this same technique could be applied to the Super 8 2t or not?
Zombie, you said you sheared the offset keys due to them not being burnished. Looking at them, they would appear to be of such design that would weaken them significantly. Any more input on that would be appreciated!
Thanks
https://www.youtube.com/watch?v=p63JXW29tVo (https://www.youtube.com/watch?v=p63JXW29tVo)
My bad. Here is the path to the video. Thanks Zombie!
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LOL... You forgot to install the link...
The flywheel, and crank taper are obviously produced on separate machines. Those machines have tolerances so every part will be slightly different.
To burnish the tapers you need to start with 120 grit emory paper, and wrap it around your taper so it fits w/ an end to end but joint. They can not overlap but there can be a slight gap.
I use spray glue to hold that on the crank taper. Next get that paper soaked w/ oil, and install the flywheel by hand. You need to spin it slowly in both directions while pushing it against the crank. Spin it four or five times in each direction, and re apply oil.
Do this until you see the inner taper is completely hatched all the way around. NO bare spots.
Then reverse the paper to the flywheel so it will now hatch the crank. Repeat the process until the crank is completely hatched.
step down to 600 grit, and again w/ 1000 grit. For the final hatch, rubbing compound... It's a paste.
The crank, and flywheel should look like glass, and they will fit so well that you don't need a key to retain them. The key is now just a guide for timing alignment, and those "weak" looking offset keys will hold forever.
To remove the flywheel will be a BITCH unless you strike the end of the puller. ONE sharp rap will allow the wheel to pop off.
Those keys create 2 or 3 degrees of advance. In reality you want around 6-7 degrees.
You HAVE to run premium fuel, and be SURE your jetting is rich enough. Borderline lean jetting will pre detonate, and melt valves.
Like B&L posted... cut the stator plate AND the pulsar coil so you can move them between 2, and 4mm counter clockwise.
Every bike is a little different but like I posted before 2mm was the "sweet spot" for mine (around 5-6* more initial, and 5-8 total at 10k rpm).
The OEM timing I believe is 18-22* initial, and 0-2* total at 10K rpm.
This mod makes 23-28* initial, and 5-8 total.
PREMIUM FUEL + PROPER JETTING!!!
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;)You have to be somewhat mechanically inclined to understand this stuff. A 3/8" mid run splice is a delicate procedure best left to idioy... or is it idiots. Latin class sucked. :-*
What "splice"......
I clearly recall the advice oftentimes given here....".trim 3/8ths off the plug wire to improve the ignition."
So I did, in the middle.
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You're an 1/8" off, and a card short.
I think perhaps Home Ec. would suit you better. Try on some aprons while I try to find the Betty Crocker forum address for you. ;)
;D ;D ;D