xr250 keeps dieing

[bourneaussie]

Went on a big ride staurday, 4 hours in to my ride it just cut out whilst going. I left it for a minute and it fired back up, turned around to ride back and 15km's later it died again, waited and restarted, died again about 15km's later. This kept happening and it started dieing in less km's and became harder to start. I ended up ditching it and hitching a lift off an old german bloke who looked like micheal caine! Recovered it on sunday and left it at home. Got up this morning, it fired straight in and i rode it to work. So obviously its an intermittent problem. The fuel tap isnt blocked and neither is the fuel filter, when it died i pulled the fuel line from the carb, tipped the bike and fuel came out so i dont think its a fuelling issue. Also i have completly stripped and cleaned the carb with brake cleaner and compressed air and replaced the needle, jets, float valve and all gaskets. So i think its an electrical fault. The coil is brand new but the cdi is still the same as came with the bike and i havnt looked at the pick up or stator yet but i wouldnt know how to test them anyway. The kick starter feels very easy to kick over, i can push it down easily with my hand, so ill compression test it later. Any ideas what it could be?

[bourneaussie]

The carb strip, clean and internals replacement was done on wednesday just gone

[Oil Baron]

I would rule out the CDI.  Check the kill switch and ground to frame for corrosion . . . . also frame to engine grounding.

Edited October 27, 2014 by Baja Rambler

[bourneaussie]

I disconnected the kill switch on saturday and that didnt fix it. I will check the grounds though. Thanks

[GregWB]

Try changing spark plug?

[Trailryder42]

Make sure fuel tank cap is venting properly. If you have one of those stubby vent lines with a valve in the end of it for your cap vent, ditch it, as they are nothing but problems.

Make sure the carb drain/vent lines are not plugged up.

If this happens again, the second it dies on you, open the fuel tank cap. If there's a rush of air when you remove it, its not venting.

[bourneaussie]

There is no pipe coming off the fuel tank cap. I removed the cap earlier and put the brake bleeder vaccum on it at work, it sucked straight through, no blockage. I also did a compression test while i was at it, tested with the decompressor disconnected (i removed it ages ago) and with the throttle held wide open. Gave it a few kicks and it read 80psi. Should be 92-107psi according to the manual but it dosnt give a service limit. The compression isnt ideal, i still think it should have more but i dont think this is what is causing my problem.

Does anybody know a way to test the stator and pulse pick up?

[ITLKSEZ]

You have to first cut the possible problems in half. Carry a can of starter fluid, and the next time this happens, give it a shot and try to start it. If it fires, you know it is more likely a fuel problem.

[Trailryder42]

What year model XR?

Edited October 28, 2014 by Trailryder42

[bourneaussie]

Im trying to avoid using starter fluid, i hate that stuff. Seen it lock up engines and even heard of it locking engines and spinning the crank in the caps!

Its a 1999 xr250r

[w00dzy]

Where does the engine to frame ground usually occur? Engine mount bolts?

[Oil Baron]

Where does the engine to frame ground usually occur? Engine mount bolts?

 

Yes, and if you painted the frame this could be a problem.

 

Also, there's no law against running a separate wire ground from the frame to engine or engine to coil.