My 92 250 ran fine one day and after being washed 2 days later it won't start. I have never been able to get this thing to idle right but it always ran strong. Mods include: K&N Filter, FMF Exhaust, Boyesen Rad Valve. This thing just doesn't even try to start at this point. When I kick it every so often it backfires and that's it. The exhaust heats up like it's been running and nothing else. I never had problems starting it before.

Here's what I've done:

Cleaned carb., replaced plug, cleaned all wiring connections, checked for broken reed valves, checked for spark (looks good), plug is wet when pulled out so there does seem to be gas reaching the chamber, plus the backfires means something is exploding. Compression is no different then before it ran and no strange noises are heard when kicking this thing.

 

Have you tried pull starting it?

 

You said "pull", did you mean "pop" start it by throwing it in gear when going down a hill? The answer is, No, if that is what you meant. This thing is kickstart only. I thought about giving this a try but wasn't real encouraged with the lack of effort it gives when kicking.

I was reading through the manual (I refuse to turn to instructions and manuals at all cost, but like I said, I'm desparate!) and the problems I am having seemed to point to a possible CDI or electrical problem according to the book. I priced these parts and for the resistor, regulator and CDI it would run about $400!

 

You say you have spark, if so, the cdi and everything else electrical is good.
Did you actually do a compression check, or just by the effort to kick start?
Youre best bet, is to try having someone else pull you with a tow strap, and try to bump start it. You only need to go about 5 mph and be in third gear,..if its possible to start it will.
Are you sure gas is getting to the carb? Open the drain at the bottom of the float bowl and make sure some comes out.
Where is the air screw set at?
Have you tried starting it with 1/4 throttle, if the pilot jet is plugged, this will bypass the problem.

 

I did loosen the nut on the bottom of the carb to see if gas would come out and it did. As far as compression I didn't test using a gauge, just the feel from kicking it. I tried several different air screw settings, the last is 3/4 turns out like the stupid manual says. I believe before that adjustment it was closer to 2 turns out (this is what it was at when it ran fine also). I think I tried every combo of throttle position without any luck. I'm glad to hear that you don't feel this is an electrical thing. I will try to pop start it tomorrow and if that fails I will do an actual compression check.

What should the compression be?

 

A trick to get a temporary increase in compression, which may help you.
Pull the spark plug out, and put a few good drops of two stroke oil, in the hole. Spin it over, with the plug out, a few times. Then put the plug in and try to start. The oil will seal the rings for better compression, and lube the walls, so itll spin easier. Using two stoke oil works best because it wont leave any ash( if its synthetic).

 

when u where washing it did u get water down the pipe?? also dose it feel like u have good compresion???it also kinda sounds like somthing is cloged in your carb?

 

Check this out before you jump track..........
Go around each and every base {cylinder} nut and make sure there pretty snugged up as well
as the head bolts samething. Try that mine did the same thing as yours and thats what it came
down to, if you hosed off the engine while it was hot or near hot, chances are that these nuts & blts, tend to do their contracting{at a faster than normal rate}, causing them to loosen up, so try that before anything else you do. You may or may not need to pop start it for the first time
after doing this to get the seal to swell up again for a good compression.
Let me know how you make out!!

 

did you maybe get water in it through the K&N filter,you getting spark?If your getting spark,try pulling the plug and pour gas in the plug hole,replace plug and give it a kick.

 

have you opened it up and checked out the magneto stator rotor coils pickups and all that. last wed. at the track i had the same symptoms and the key was broke so the timing was all wacked. we cut off a piece of a lockwasher and stuck it in there. not recommeneded for long term use[img]i/expressions/face-icon-small-smile.gif[/img] if youre getting any spark at all i wouldnt think its your cdi. that or youre just flooded. give it a squirt of starting fluid in the airbox.