2004 yz250f starting issue

ken.milesky
Posts
40
Joined
3/8/2013
Location
Boonton, NJ US
3/15/2015 4:30pm Edited Date/Time 3/30/2015 6:05pm
Last year i was running into issues with the bike being hard to start when trying to kick start it. It will bump start every time with no problems but if I try kick starting it I rarely get it to fire up. When it's running it runs awesome. I took the carb apart checked the Jets and made sure they were clean as a whistle and they were all good. Changed the airfilter and even did a top end rebuild to alleviate the potential question of compression. Now when it is running it runs even better! But still when I try kick starting it i run into the same problem of it not wanting to fire up until I bump start it. When I did the top end I made sure the Valve clearances and timing was on point and it was. So I'm running out of things that it could be...im thinking a new kickstarter lever because it's pretty old and foot slips off pretty easily especially when Alil wet. Also the carb floods and overflows so It might be a a wrong air to fuel ratio in the carb. But it never had an issue until last year. Going to get a new float bowl and new jets (keeping the same sizes because like I said when its runing it runs amazing.) carb is clamped in perfect and air box is clamped perfect to ensure no leaks. Can the kickstart internal mechanism break down and become less effective? Also any other ideas on what could be happening that is preventing me from being able to kick start my bike and get it running? Oh and yes I made sure I had fresh gas, oil and changed the plug. Please help thanks everyone!
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Paw Paw 271
Posts
3640
Joined
4/3/2013
Location
Benton, LA US
3/15/2015 5:48pm
The kick starter should not be the problem.

When you did the rebuild....
Did you have to re-shim the valves? If so, it may be time for new valves. Have they ever been replaced? What are the valve clearances right now?

Did you replace the cam chain? If no, it could be stretched and not keeping correct cam and valve timing.

Are you sure the coil mounts and wires are free of rust and dirt? Do an OHMS test on the coil.

The flooding is a real problem and needs to be fixed as these bike are real stickers for having the right fuel mixture.
What is you fuel screw set at?

Is the fuel accelerator pump in good working order and timed correctly?

If you replace the jets....Replace the starter jet, pilot jet, main jet, the leak jet and the float needle and be 100% sure the carb is
100% clean.

Paw Paw
ken.milesky
Posts
40
Joined
3/8/2013
Location
Boonton, NJ US
3/30/2015 6:03pm
Paw paw, thanks for the trouble shoot list! It kind of scared me at first but I had a feeling that it was the carburetor but if it wasn't I wanted to have a list of other things that it could potentially be so that was very helpful but it was actually the carburetor. The fuel line hose that I was using prior became dry rotted and I think parts of the rubber got into the carburetor so after a good cleaning and new Jets and finagling with the float bowl that stopped the flooding and fired right up a couple kicks. I went riding on Sunday as a real test and stalled in the woods and was actually able to start it for once which was pretty exciting!!!! Thanks again
ken.milesky
Posts
40
Joined
3/8/2013
Location
Boonton, NJ US
3/30/2015 6:05pm
The kick starter should not be the problem. When you did the rebuild.... Did you have to re-shim the valves? If so, it may be time...
The kick starter should not be the problem.

When you did the rebuild....
Did you have to re-shim the valves? If so, it may be time for new valves. Have they ever been replaced? What are the valve clearances right now?

Did you replace the cam chain? If no, it could be stretched and not keeping correct cam and valve timing.

Are you sure the coil mounts and wires are free of rust and dirt? Do an OHMS test on the coil.

The flooding is a real problem and needs to be fixed as these bike are real stickers for having the right fuel mixture.
What is you fuel screw set at?

Is the fuel accelerator pump in good working order and timed correctly?

If you replace the jets....Replace the starter jet, pilot jet, main jet, the leak jet and the float needle and be 100% sure the carb is
100% clean.

Paw Paw
Paw paw, thanks for the trouble shoot list! It kind of scared me at first but I had a feeling that it was the carburetor but if it wasn't I wanted to have a list of other things that it could potentially be so that was very helpful but it was actually the carburetor. The fuel line hose that I was using prior became dry rotted and I think parts of the rubber got into the carburetor so after a good cleaning and new Jets and finagling with the float bowl that stopped the flooding and fired right up a couple kicks. I went riding on Sunday as a real test and stalled in the woods and was actually able to start it for once which was pretty exciting!!!! Thanks again
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