Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: JPond53 on October 02, 2011, 10:09:44 PM

Title: YZ 250 Engine Problem!!!
Post by: JPond53 on October 02, 2011, 10:09:44 PM

Okay, so my buddy has a 1996 Yz 250. We were at the track today and were already riding for a good 30-45 minutes roughly. Then all of a sudden my buddy is on the side of the track so the problem is now the bike won't start! We checked the spark plug and it was pretty clean and also had spark, bike has compression, we checked the air filter which was dirty but not that bad to not start up again. We turned the fuel off and tried starting it with it full throttle and still nothing we tried bump starting it stilllll nothing! ???  We even tapped the float bowl on the carb a little bit because somebody said sometimes the pins gets stuck or something like that but we tried that and it didn't work...I'm out of ideas just about I mean the only thing left I'd say would be pull the carb and clean the jets in case a piece of dirt is in there, and if nothing after that pull the top end and check it out and see what's going on internally? Any help would be great thanks guys! 8)

Title: Re: YZ 250 Engine Problem!!!
Post by: TMKIWI on October 03, 2011, 12:29:07 PM

If you have spark it is probably fuel.
Do you have fuel in the carb ?
How did the bike stop ?
Did it quit suddenly or did it putter out. All are clues to what may be wrong.

Title: Re: YZ 250 Engine Problem!!!
Post by: JPond53 on October 03, 2011, 02:21:28 PM

Yeah fuel is in the carb and my buddy said it sputtered out...like as if you were to run outta gas. When we try and kick it over with no throttle it sounds completely dead but when you do a full throttle start it sounds like it has potential to start but doesn't.

Title: Re: YZ 250 Engine Problem!!!
Post by: overthebars on October 03, 2011, 02:27:56 PM

Checked the reeds?

Title: Re: YZ 250 Engine Problem!!!
Post by: JPond53 on October 03, 2011, 02:36:23 PM

That I have not!  ::) What would be wrong or something to look for if there was a problem with them?

Title: Re: YZ 250 Engine Problem!!!
Post by: oldermxr on October 03, 2011, 04:55:27 PM

you would have to pull the carb off and take the reed cage off and take apart and check the reeds for breakage and or cracks aspecially around the edges/corners if any are detected the reeds need to be replaced

Title: Re: YZ 250 Engine Problem!!!
Post by: JPond53 on October 03, 2011, 06:10:31 PM

Would that be enough to make it not start though??

Title: Re: YZ 250 Engine Problem!!!
Post by: SachsGS on October 04, 2011, 06:34:35 AM

120 PSI compression minimum.Blue spark (not white). New sparkplug - does the old plug show lean or rich? Check your flywheel key - they shear sometimes. ;D

Title: Re: YZ 250 Engine Problem!!!
Post by: JPond53 on October 04, 2011, 08:09:39 AM

^ I will do this and get back to you!  :P