engine problems???

R

rwalton3563

New Member
i have a problem getting my bike up 34 mph like it used to... it now barely gets up to 22!! the engine used to pull hard with no problem right up to 34mph..now it takes a while just to go 22mph...any ideas on what happened i run the engine 20:1, 25:1 i dont think the fuel is a problem...any ideas??? thanks... rwalton3563
 
I'd check your head bolts first. Then use some wd-40 and give it a few squirts where the carb attaches to the intake, where the intake attaches to the motor. Listen for the motor idle to slow down. Then some squirts around the cylinder base. Listen again for the motor to slow and look for bubbling out of the base gasket. Oily residue around the cylinder base, or around the underside of the head are sure signs of a leak too.
 
Did you check for leaks at the carb mount and intake mount? Did you find any oily residue at the head seam or the cylinder base? If you don't find any try removing your exhaust and using carb cleaner spray/pour into the cylinder end of the exhaust and flush it out well.
 
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Oh man this is getting hard, If you have one of the mufflers with the cat in it try flushing it out with carb cleaner like I said. If it's been a slowly getting worse problem the muffler may be getting plugged up. Your still using a pretty high oil mix. Try going to synthetic and 32:1 (4oz per gallon) after you flush the muffler. If that fixes your problem. You cannot tell by looking if you have a intake leak. Even if you use water mist both ends of the intake. Ok and I'm assuming the problem is the motor is running slower not just as fast but the bike isn't going.
 
O.K., Look at your plug first. Should be light brown thru black but not too oily. White or gray is lean, black sooty or oily is too rich. Brown like chocolate is about perfect.

Confirm fuel flow and check the float bowl and jet to be sure they are clear.

How many miles are on it? How do you know for sure it's lost speed?Check the accuracy of your speedo.

Does the engine sound or feel any different than before other than the loss of speed and power?
 
I had the same symptoms: loss of power and the choke had to be constantly adjusted. I tightened the head bolts and the intake bolts - it helped a little but when I took off the float bowl, there was this brass thing about 1 inch long in the middle of the float that had come along for the ride. The jet had completely unscrewed itself! Made a big difference. I also found a bunch of crap in the fuel shut off valve. The only way to really clean it out is by blowing compressed air through it both ways.
 
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Make sure the Ex port is no carboned up, also make sure the rings are free in the piston, not gumed up. Vic
 
Take exhaust off barrell and check the port is clear and not carboned up. Also lock through port at piston and rings (rotate motor to align).
Does the motor still have good compression?
 
When checking for Air Leaks use Starter Fluid Works ten time better the any thing else. If there is an air leak the motor will speed up. It's harder to check crank seals, but both sides are very important. A small air leak will cause a lean mixture and hesitation when accelerating. Lean Mixture runs hot. When your breaking in a new motor never run long periods at any one RPM. If you are running lean at 1/2 throttle you could size a piston at 1/2 throttle. Never go down a long hill with the throttle completely closed. If you go directly to wide open you can do damage due to lack of lubrication. Blip the throttle ever once in a while when going down long grades.
 
Probably yhe piston circlip has fallen out of its groove and the gudgeon pin has graunched into the barrell. You will need a new piston,piston rings and barrell.
 
no i did not get it fixed...top speed is 25...im really thinking about a different carb...something that is can be tuned..like some have a high speed screw and a low speed screw..thanks for the info everyone:-||
 
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