Fuel pump yamaha ybr 250

SOURCE: Oil

drain the fuel, locate the float bowl drain screw, lowest screw on the carb and loosen it to drain the carb. replace the fuel with proper pre-mix, replace the spark plug and it should be fine

SOURCE: Front sprocket

Hi ........... One tooth less will give you more top speed (if you can pull top revs) but will reduce accelleration. If you go for one tooth less you'll need to tighten the chain and/or remove a link. It's a trade off ............ decide what you want the bike to do.

SOURCE: What are the valve clearances of the engine of

Valve clearances are
in 0,12 mm
ex 0,15 mm
on cold engine

SOURCE: yamaha ybr 125 top speed

Hi les
Not much to start with here unfortunatly mate. A free flow muffler will help top end speed, change the factory airbox to a K&N style pod air filter, other than that, hugging the tank at top speed :) If you do change these parts, you may also need to increase the main jet size to richen up the mixture for better tuning of the motor with the better flowing parts. This bike has a top speed of 100kmp and produces 10 hp, so you may only expect to get at best less than 1 extra neddy, and perhaps another 5 km/hr.... I suggest upgrading to a bigger machine of you feel the need for speed :)
If its 125's you are into, test drive a Honda CBR 125R 6 speed fuel injected 13.4 horsepower, and good for 120km/hr
regards robotek

SOURCE: 2001 yamaha ttr 250, starts, idles ok, bogs at acceleration

I have the same bike and same problem. Check the intake hose that connects the carb to the motor it may have a crack mine did and lost power when the bike warmed up. They don't make a replacement hose for it so I am using a rubber plumbers coupling with hose clamps. Might work? The hose is inch and a half diameter and about three inches long try that maybe. Good luck If it makes a chirping sound when the bike gets warm it's probably that hose sucking in air and screwingup your mixture.