I have a 2000 cbr f4, and it ran great until I did some maintenance stuff to it. Now it won't run. It sometimes feels like it kinda tries to start but won't. If I leave it for a couple hours it will start and run for like 30 seconds but then dies like its running out of gas. It has new sparkplugs and carb rebuild, the only thing I can think of is if while cracking, it just washed the cylinder walls and drained fuel into the oil. Does that sound like it could be the cause or any other ideas?

 

no, that is not a likely problem to have since you did NOT do anything to the piston rings/cylinder walls.

here's what happened. and this is what you need to be able to do in order to break down the question of whats wrong.

Bike works. - but could use maintenance

you changed sparkplugs and rebuilt carbs.

bike doesn't work now.


if you replaced sparkplugs with the correct ones - which if they went in easily enough, id assume so as long as the gap wasn't rediculous, that's not the problem.

id say the problem is in your carbs still. could be that they're not synced, could be that something is in the jets, float valve, the list goes on and on. i don't have anymore info than that, so i don't know what it is. but you have to work through the problem with cause and effects.


you can do a compression check in order to test your theory, but i'd doubt thats the problem since nothing was done to the inside the motor.

 

Well it started this problem before I did plugs and carb rebuild. Those were just things I tried. I first cleaned the plugs with a wire wheel like I do my car plugs but that must have messed them up cause that's when the problem started. Then I replaced the plugs and pulled and checked the carb but it still won't run for more than 30 seconds at a time if I let it sit for a few or more hours. Then dies like its running out of gas. I also replaced the clutch lever on the clutch cover cause it broke but that has nothing to do with the problem unless I messed the crank position sensor up. At least I think that's what it is.

 

When you rebuilt carbs, did you remove the mixture screws or turn them at all? If so, they may need re-setting to the basic settings. Turn each screw clockwise gently until they won't turn any more. Now unscrew them anti-clockwise and depending on your bike model and your location the following number of turns: European model 3 turns. Californian models 2 and 3/8s turns. Swiss market models 3 and 1/4 turns. US 49-state and Canadian market models 3 and 1/8 turns. I assume you didn't alter any of the carburettor floats heights as this determines how much fuel enters the float bowls. Too much will cause engine flooding-too little and they will not have enough fuel to keep the engine running. Hope I've given you something to work that may help? Let us know how you progress?

 

Yah ill try that tonight... I now have the bike to the point it will run awsome for 20-30 seconds then sputter off and die like its running out of gas so ill try adjusting the floats first. Sounds like thats the most likely culprit. Thanx for the help. I'm kinda a tard with carb stuff