50cc Scooter - Loss of power)

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If your bike has no visible fuel tap.....
Disconnect the petrol pipe that feeds the carb. If no fuel flows, discover the vacuum fuel tap, under the seat somewhere.
Note there are three pipes - one from the tank, one to the carb, and one to the engine. This is the vacuum pipe. Disconnect the pipe and suck on it....petrol should now flow from the tank to the carb.
Its always worth checking this, even if its just to rule it out.
John :)
 
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hi i have took it all apart and found that there was air and oil and fuel leaking from the crank shaft seals so im buying some of them, will that fix the problem i have do you think? thank you :) reece
 
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On two stroke engines, air can indeed be drawn through worn crankshaft bearing seals...this upsets the fuel mixture big time and makes carburettor adjustment impossible and unreliable.
Usually its best to replace the main bearings as well as the seals. Seal failure is usually a lubrication issue unless the engine has done a huge mileage.
John :)
 
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ok where would i get the bearings from? ebay? its a cpi aragon gp 50, and ok im gunna buy new seals for it :) and would that be the only problem if ive replaced everything else? and everything else is spot on! its only done 9,000 on a 08 plate :)
 
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Any bearing factor will match the bearings for you, so long as you take them with you....the oil seals are more of an issue, so check out scooter importers as the seals are often the same and aren't make dependant.
I use a firm in Newcastle called Formula One Engineering, Westgate Road when I need bits like these. It may be worth a Google.
John :)
 
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hi sorry for late reply, i changed the seals and put the 21mm carb back on instead of my 17.5mm and my 60cc big bore kit and everything back on and it is still doing the same thing! and not accelerating that much does like 5mph then when i push it and go down a hill it starts geting up speed but then when i slow down to a stop it does it again :cry: :mad: :mad: :mad: :mad: :mad: :mad: :mad: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :mad: :mad: :mad: :mad: :mad: :mad: :mad: :mad: :cry: :cry: :cry: :cry: :cry: :cry:
 
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This may sound a bit anal, but when you put the new piston on, did the arrow on the top face the exhaust port?
John :)
 
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Did you try it with the exhaust disconnected?

Could be blocked
 
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yeaaah it did and no ;/ i dont know if it needs a new exhaust like a performecne exhuast for air and fuel
 
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Did you try it with the exhaust disconnected?

Could be blocked

Excellent point - guaranteed to nobble a two stroke , that one ;)
Still not the issue, it seems......a performance exhaust wouldn't affect the general running anyway.
Have you had the ignition flywheel off at some time, Mr Reece?
John :)
 
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hi i have tried everything else except from the taking off the exhaust, and no i havent why? and is it better to just buy a new engine?
 
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