KymcoForum.com
Scooters - 50cc => Agility 50 => Topic started by: Matty on December 18, 2011, 02:37:30 PM
-
ok, here's a classic.
Having been messing around with just about everything on my agility 50 for the last 4 months, I seem to have got it running ok.
Then on the way home last week it suddenly went from running fine to giving very little power and not revving to maximum. I rode it about 2 miles like that.
Scratched my head for a bit and realised I hadn't changed oil in forever. Turns out there was only about 250mm in there. Ouch. Changed it this morning (went from 10w40 semi synthetic to 15w40 mineral as it's all I had).
Took the bike out - it ran fine again for about 7 miles, then started failing again in the same way as before - poor power, won't rev fully.
Have I stuffed it?
-
You said your messing around with everything can you explane that better. Did you do valve check and clean the carb and at one time did you cut the cdi box because if the cdi box got wet you may need a new one. how good is the belt and the rollers and did you take the clutch apart and clean it.
-
Valves - yes checked these. They're within service limits
Carb - checked, was clean. Replaced main jet with #82 (I have been trying to re-restrict as I think the last owner de-restricted)
CDI - not cut. Original
Belt - new.
Rollers - original 6.5g (I think). A bit dirty but I've given them a spit polish. Within service limits on diameter. Tried 5.5g but revved like crazy.
Clutch - not taken apart. Only taken apart the driven pulley of the cvt. Couldn't get the cluth nut off.
Bikes only done 5000k. Could all this be down to the oil type? Like I said it seemed fine for 7 miles after the change, then died again??
-
wont hurt anything to try a oil change I would go with 15/40 full synthetic valvoline I have been useing that in my scoot for 5 years now.as far as restrict or scoot you need a bigger jet and change out the drive boss and cut the cdi box. Good luck.
-
I would be intrested to know where the oil is going over half a litre in less than 5000km, i check mine every 1000km and change every 4000km and in that time never have to top up, i wonder if its getting into cylinder from pre worn valve guides or piston rings and fouling your spark plug, although with only 5000km on your scoot you should not have worn piston rings etc if your bike has ever ran leen/hot for any length of time this can cause your piston rings or valve guides to soften and wear faster, is your exhaust giving out much smoke otherwise to be losing that much i would think you have a leak somewhere, kymco recomend 10w50 or 15w40 mineral so you should be fine i use 10w40 fully syn as i want the scoot to last me as long as possible and 10w40 being a littlle thinner flows better especialy in winter....
-
Thanks, Kisbee
Yes it did seem strange to lose so much I did a full replace at around 3000km.
I can't see any evidence of smoke.
Where might a leak be? Could a leak be affecting pressure and therefore performance? Or does oil pressure not really matter for scooters?
-
Is there not oil on the floor where the scoot is parked over night if not i would guess its not from the drain or oil filter bolt other places could be crankshaft seals and it leaking down behind the variator pully but that amount i would have thought would have got on your drive belt causing it to slip and also found its way out of the cvt cover by now and if it was the stator/fan side would be leaking out onto floor if you cant see any oil drops under scoot or on floor then i would guess its being burnt up in the cylinder, have you checked the plug lately to see if it looks oil fouled could explain the poor running....
-
If it runs fine, then goes bad, I doubt it would be a mechanical fault, unless it is something heating up.
For the losing power, I would be looking at the fuel system, Filter, hose, vacuum hose, and fuel cap vent as it sounds like it is starving for fuel. If it is running too lean, it could be heating up to the point of almost seizing, hence your loss of power. Did you have this problem before you changed to the 82 jet? What size jet was in there before? Is the air filter stock? Or has it been opened up for better flow?
-
No oil on the floor
No oil evident inside the clutch/variator casing, and no oil on the belt :(
Never opened up the crankcase so can't comment there.
Air filter stock
Don't know what jet was in there before, but suspect it was actually the stock 80 (the last owner doesn't know if it was rejetted or not)
No obvious leaking around the drain bolt or oil filter.
Plug always looks fouled to me but I checked and cleaned it immediately before the oil change so I can't imagine it's clogged up that quickly? Is it possible for a plug to foul up in only 7 miles of running?
What's odd is that after the oil change it was running fine for 7 miles (say 30 minutes) then slowed right down. Now when I start it it's already in the "go slow" state.
Maybe it is the spark, but that would mean either it's set waaay too rich, or there is too much oil in the cylinder ie. failed piston rings. Correct? Or possibly weak battery - I did briefly charge the battery before I started the 7 miles. Does it make sense that it would produce a weaker spark after 7 miles of riding? I thought they charged as they went?
Maybe that's it? Any thoughts?
-
to much oil is just as bad as not enough. drain a little tell it shows on the dip stick the right amound.
-
If oil is getting into cylinder especialy the amount you are going through over 500ml in 2000km then i would say it could foul up the plug within 30 mins of riding, i dont think even my old peugeot 2 stroke engine went through that much oil LOL ;D have you checked plug since your 7 mile trip. As for the batt after your 7 mile trip did you try the elec start if it can still turn engine over then it must be charging itself and yes it does charge when engine is running, are you having batt problems why did you need to give it a charge or are you just draining it because its hard to start?
-
Hi kisbee
Yes still turns over fine after the 7 miles with electric start and always has.
I just had a few people suggest it might be weak spark so charged the battery to see if this made a difference.
I also replaced the high tension wire/coil with new but that made no difference.
Think it's time to take it to a garage or put it in the bin...
-
Try reinstalling your original jet in the carb. Or, remove restrictors in the air box. How is the exauxt tip? Is it moist whith fuel? What color is the plug? When you say it slows down, is it the engine that is losing revs or is it just slowing down as if someone was applying the brakes? Have you checked the oil level in the rear transmission? Is the rear wheel spinning freely (normally) when the scooter is on the centerstand? Could be the transmission seizing up. Is the fuel properly reaching the carburetor? is the fuel filter clean if one is installed? Is the fuel petcock functioning properly? Does the engine regain its power after being stopped for a while? Is there gas leaking on the ground when it stalls?
What i'm trying to get at here is the fact that you are not clearly describing what really happens. It is therefore somewhat difficult to try to find some kind of explanatio to your problem!
-
Thanks for this, Spidrgr.
Interestingly, here's what just happened on my way home tonight:
0. As discussed, I left the bike at the office last night after it died, and when I tested it at lunchtime it still had poor power when I started it up.
1. I trickle charged the battery after lunch for 4 hours
2. I put the battery back in the bike this evening and it ran fine for 3 miles.
3. Then it died back again to low revs and low power. It stayed like that for about 4 miles whilst I rode slowly at lower revs
4. Then it suddenly picked back up again and worked fine for the last mile of my journey.
Mental. Could too much engine oil be the cause of this? Ie. when hot it expands and the power goes, then when it cools back down again, the engine runs ok? Anyway, I've drained some oil out, cleaned the spark, recharged the battery and replaced the fuel filter tonight so let' see what happens in the morning (UK time!).
Spidrgr to answer your questions:
1. I can't face reinstalling the original jet. I don't think it's this as the bike has been working fine with the current jet (if intermittently)
2. Restrictors in the air box...I didn't even realise these existed - probably one for later - I'd rather get it running normally first
3. The plug when I took it out tonight was black on the metal part around the white central "island", but the island was white, not black
4. Engine is losing revs. It's not as if someone was applying the brakes. Acceleration dies to super slow and top speed drops to around 28kph
5. oil level in the rear transmission - I replaced around 2000km ago, but you're right I will check this weekend
6. Rear wheel spinning freely when on centrestand
7. Fuel - I have thought this too, but I cleaned out the fuel lines, and fuel was flowing freely under gravity
8. Fuel petcock - Tested this a month ago and was fine, so don't expect this is the problem.
9. Does the engine regain it's power? Not after being stopped for a while. However if I recharge the battery, it will regain it's power after being stopped and the battery charged.
10. No evidence of gas leaking, plus have decent mpg still.
-
mmmmmmmmmmm when you had the cab apart how was the diaphram. is everything in the carb working ok.
-
diaphragm a-ok. everything else clean as a whistle.
-
Still running poorly after sitting says that it is not a heat problem, picking up and running ok for a time and then going back to running poorly again, I would now be looking at the electrics, firstly going over all the connections making sure they are clean and tight.
-
thanks sid
i've ordered a new battery as a starter for 10.
I'm learning a lot, but this is getting expensive! ;)
-
learning is good.But befor you spend to much be sure of the problem frist so you dont over spend.I learned that the hard way. Good luck with your scoot.
-
Thanks, blue.
Here's one to add to the diagnosis clues:
This morning, having cleaned the spark plug, charged the battery and replaced the fuel filter everything ran fine for...1 mile.
Then I stopped at a traffic light and the engine cut out (this is normal for my kymco and not part of the diagnosis).
I restarted using the electric start, and after this the bike was low on power like it was yesterday. It stayed like that for the rest of the journey.
Thinking back, it was after restarting from warm on the electric start yesterday that the power dropped.
Does this suggest anything different?
Spoke to Kymco and they seem to think if the battery is strong enough to start the engine (which it comfortably is) then the above is unlikely to be a battery problem. I'm not sure that's right though - seems like a big coincidence to me.
-
Did you ask kymco them about your oil loss, i doubt it is your batt as once your scoot is running your stator will provide your electrical system with all the current it needs even if the batt was near the end of its life, many people who's batterys fail drive round for months before replacing and just rely on kick start and dont have problems with weak spark even i have done it on a boatian scoot i had a few years ago.....
-
ok. developments...
Found a loose bolt on my crankcase last night, though can't remember which bolt it was. May have been the refill bolt, may have just been a bolt to hold it together.
Either way I replaced my transmission oil last night. This morning on the bike, I had 5 miles low power first, then 3 miles good power (if a little poor at low speed), all on the same journey.
So, may have been transmission oil, but still suspect my battery - my lights dim and flicker pretty seriously when the bike is idling. If not the battery, and not the coil (recently replaced), I guess this may be some other electrical issue. Will get the manual out.
-
sounds more like a power think to me like a new battery.When comes to batterys rember this a battery well stell run lights and horn. But hey have a cranking charge also that need to be stronger then the power to run the lights if the cranking charge is low the stator wont charge the battery at all.ounce you lose the cranking amps the battery is toast.
-
Are the headlight and dash lights powered by the battery or the generator? If powered by the battery, then there may be a fault, but if powered by the generator, then flickering with engine at idle is normal.
-
My scooter buddies would call this "a test from the Gods"! Good luck and hope you get her fixed.
-
Thanks, guys. This bike has been a headache since I got it. Sidthesloth - I don't know whether the lights come off the battery or the stator, but I would guess the latter.
on the plus side I figured out how it was derestricted (variator boss), but in terms of running, if it's not one thing it seems to be another...
Here's what's happened the last two times I've used it:
Runs fine in the morning full power UNTIL my first stall of the day (normally at a traffic light). After restarting using the kick OR the electric starter, the power has gone and it stays at low power.
I know I can get round the above stalling by adjusting my idle, but I'd still like to get to the bottom of the problem. New battery is going in tonight but this is mainly a short in the dark. So the question is...
What happens when a bike stalls that might create a "low power" condition immediately afterwards?
Answers on a postcard to "losing the plot, london, uk".
-
Go over all the electrical connections, test the stator, cdi and regulator, if you can replace these I think you would have it sussed. If not willing to throw the money at it that way, just test the items with a meter using the manual for reference.
-
changed the battery today. No difference.
That was an expensive test.
-
Boy you got me thinking.I would just keep looking over everything make sure there are no holes in the air box or hose that goes to it. make sure everything got put together nice and tight. what year is the scoot did you buy it used.
-
With you saying the scoot runs ok the first couple of miles im thinking that maybe it could be the auto choke sticking on and causing it to run to rich once the scoot is at running temp and fouling plug, or from what else you have said maybe possibly a wet spark plug caused by oil slowly getting into the cylinder especialy as you have still not found a external leak and all that oil went somewhere and you did say your spark plug always looks dirty.....
-
Agree with Sid this sounds electrical. One thing you haven't said you've replaced is the spark plug. I'd do that at least.
Keep reporting back. I hope you get somewhere with it. ;)
-
try unpluging the auto choke and run the scoot like that for a few miles.
-
Ok then, a Christmas update.
This seems to be a carb problem.
I took the carb apart, blasted some compressed air around it (again) and put it back together again. In reality, I don't think it was blocked in any way, but did it for good measure.
After that, it seems to be working ok again now.
Then I rode it 45 miles twice (visit to parents) and now it seems to be running ok, if a little hard to start. In fact, it's now running faster than ever.
I'm sure it will fail again - at the very least I don't think the carb is property tuned - but at least I know it has something to with the carb in one way or another.
Thanks everyone for your help with this. I seem at the moment to have got there.
Matty
-
Try to take it in for a carb adjustment.good luck happy you found the problem.
-
Congrats on getting it running like it should.
-
Congrats on getting it to run properly :)
And its always good to have a fresh battery, as the more powerful spark easier will ignite faulty mixtures, giving more room for faulty carburator adjustments, than a flat battery. :D
-
Happy my Yager does not have a carb.
-
yeah. I get the feeling the new battery has helped.
It seems to be starting ok-ish now as well.
I think i've squashed the carb gasket as it was ill-fitting and now it stinks of petrol all the time. Probably leaking a little so have bought some instant gasket to seal it up when I get the chance.
Other than that seems to be more or less there.
Don't suppose there's any other known causes of petrol smell?
-
If you have problems igniting the fuel mixture and cant fix it by adjusting the carb, an iridium Spark Plug and a 30k volt coil will help alot. These will also help keeping the engine temperature down.
The gasket sometimes loosen itself, and become ill-fitting, from the high temperatures right over the engine. Put it in the freezer or refrigerator (or if you live in the colder areas of the world, like I, you can leave it in the garage over night.), and it will fit perfectly into the carburator again next morning. :D