Possible Clutch Problems By usmcmech87 (Read 778 times)

[usmcmech87]

First post here, so I hope I am not doing this wrong.  I am attempting to diagnose issues I am having with my 150cc GY6... I was riding and one day I went to start it and it decided not to go past 30 mph and takes some time to get up to the speed.  

When its on the stand, it accelerates just fine RPMs and all shoot up no problem.  It's when there is weight that the scooter has problems (I am only 180 lbs).  So I started with replacing the belt and rollers (not performance) and I am still having the same issues.


I have a hard time thinking its fuel since its fine on the stand, but I am no scooter mechanic.  Any help would be greatly appreciated as I am trying to avoid nickel and diming myself.  

[Alleyoop]

It could be the clutch slipping bad but usually if it is slipping starting off will be jerky lerky slipping and grabbing etc.. Try it get on it and throttle up slow and see if it shudders and or jerks on you. Also make sure there is no oil in the CVT that will cause the belt to slip. If oil it could be the crank seal behind the variator or the seal the the tranny seal. Or could be oil from the valve cover vent hose is above the cvt area.

[tvnacman]

the brakes could be tight or draging.

John

[rosiemoto]

Another place to check is tire pressure... it could be contributing. My tires were both only 2 PSI under normal and it was making my bike feel sluggish. I fill mine up to what the side of the tires say... for my bike that's 33 PSI rear and 32 front.

[aloharide]

Fuel filter/filters partially clogged? Air filter dirty?

[usmcmech87]

Replaced rear clutch, out new fuel in, rollers and cvt replaced, wiped the belt down, and the problem persists. I was going to bite the bullet and buy a whole new assembly but I am feeling a little hopeful still.

[Alleyoop]

Can you describe what it does when you are on it and you open twist the throttle to go? Sounds like it has a problem with the fuel delivery.
Alleyoop

[usmcmech87]

It sounds like it's bogging to get up to speed. Max speed was 37mph.

[Alleyoop]

Great!! now bogging is the sound it sort of makes when you open the throttle which MEANS to much AIR and not enough fuel.

Have you done anything else to the scoot like putting on a free flow filter or changeing anything on it?

[usmcmech87]

No I have mmt changed a thing. Rode it fine and parked it. Went to ride the following day and now I'm where I'm at.

[Alleyoop]

First thing is to check all your hoses and see if something has come off their connections and or the air filter tube partly came off the carb etc.. If you could take some pictures of the carb area hoses it may help maybe spot something not connected. Have you checked the fuel filter, and make sure it is not partly clogged, you can usually tell if it is dirty or clogged when you can see black specks on the filter.
Alleyoop

[Alleyoop]

If all that is good then the next thing is to adjust the carbs fuel mixture, if the temps changed from mild to much coler then the motor needs more fuel.
Follow this procedure to adjust the mixture it is a step by step so you can't go wrong.
Alleyoop


scooterdoc.proboards.com/thread/1499/4ts-carb-tuning

[usmcmech87]

Thanks all to who participated with this. The problem was an eye opening experience for me in the scooter mechanic world. Took the carb off just to inspect and the problem was right there. A tiny cut in the rubber diaphragm on the carb was the issue. Replaced the carb as I had already purchased a new one and scooter is as good as new.

[Alleyoop]

Great news!! Good job
Alleyoop