When accelerating scoot stalls out can't past 20mph or 3rpm By kevondeck (Read 643 times)

[kevondeck]

I have a 2008 roketa 250cc scooter with the 257cc motor just bought it used been using it for a week runs great tops out at about 75mph. Recently after i tried to ride it it just won't exceed more than 3-4rpm when giving more throttle it stalls and cuts off everytime except when on service stand. I can rev it all the way to almost max rpm it seem to only do it when I'm on the scooter! I've changed spark plugs, gear oil , motor oil, cleaned carb and it still does the same thing? Please help really want to enjoy my scooter!

[scooter12]

I would do a valve adjustment.

[Bashan]

Yes, the valves are first. Then I'd check the air filter and make sure everything associated with the intake system is tight and something hasn't worked loose like an air hose.

[kz1000st]

If it's not the valves your carburetor diaphragm is torn. It's a pretty typical problem on the Linhai 257.

[kevondeck]

Thanx for the quick feedback i will def check the valves and the hoses


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[JR]

Apr 16, 2014 0:13:48 GMT -6 kevondeck said:

I have a 2008 roketa 250cc scooter with the 257cc motor just bought it used been using it for a week runs great tops out at about 75mph. Recently after i tried to ride it it just won't exceed more than 3-4rpm when giving more throttle it stalls and cuts off everytime except when on service stand. I can rev it all the way to almost max rpm it seem to only do it when I'm on the scooter! I've changed spark plugs, gear oil , motor oil, cleaned carb and it still does the same thing? Please help really want to enjoy my scooter!

Nope a torn diaphragm is not the typical problem here, man hasn't even touched a 257 linhai but what is typical on this problem is the main jet stopped up. Torn diaphragm is a possibility and does need to be checked but it's not typical of this scooter.

If you said it was dying at every stop then valves is the problem and while it won't hurt to adjust the valves while ya got it down, open the carb up again and look very closely at the main jet, check to make sure the tiny holes are all open. Had this happen to my wife's linhai last year and did a quick clean of the carb but didn't pay close enough attention to the main jet and after another look found this was the issue.

Also if it does have a torn diaphragm it's almost as cheap to buy a whole new carb versus the diaphragm.

JR

[Alleyoop]

Its the valves if it was a ripped diaphragm it would also do it on the center stand opening the throttle. The problem is it can't take a load due to loss of power which valves not sealing will cause.
Alleyoop

[JR]

My thought too but can't rule out partially stopped up main jet, same thing happened to me. You could get her up to top throttle on the stand by easing it up little by little, put a load on her and the bottom fell out.

I would adjust the valves first, then if she still stalls time to get the carb main jet out.

JR

[kevondeck]

Thanks everyone it was the air box i was told by a mechanic he fixed it now it runs smooth


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[Guitarman]

Huh? That makes no sense...

[kevondeck]

Idk thats wat he told me


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[Bashan]

Apr 17, 2014 1:14:30 GMT -6 Bashan said:

Yes, the valves are first. Then I'd check the air filter and make sure everything associated with the intake system is tight and something hasn't worked loose like an air hose.

Hello?! I think I'm being ignored! Actually it does make sense. First, a pre carb air leak dramatically leans out the mixture so you hit the throttle and the gas is woefully inadequate to balance out the air. Second, it reduces the vacuum inside the CVT carb which operates by the vacuum pulling the slide up. Slide no up....needle no up....no extra gas. Hello?!

[Guitarman]

There ya go 'splainin' stuff again... Yep. I thinked of that afterwards.