A friend's kid has a 97 250 Trail Blazer. It won't start or fire, but cranks well. The spark plug sparks well when laid on the head. After cranking with choke, the throat of the carb is wet with gas. When cranking, the carb seems to suck in air well (hand over throat feels suction). Gas appears clean and I'm told it's fresh. In the past the ATV would run fine for 15-20 minutes, then sputter and die, then would not restart, but would start after sitting a couple of days. I'm stumped. Any suggestions?

 

Have you checked compression??

 

Haven't checked compression other than feeling suction at carb throat. Don't have compression gauge. What do I need to check compression?

 

$20 dodad from our fav autoparts store that you screw into your sparkplug hole *Taking out the sparkplug that is* and it measures the compression as you crank it over..
I had a problem with mine where the lower gasket *I think it is called the crankcase gasket* was leaking..low compression = start sometimes or a bi*** to start..just a thought

 

I'm headed out to get a compression gauge at NAPA. It's getting gas and spark, so I agree that perhaps the compression is too low to cause firing. Thanks.

 

Good luck..

 

I have been dealing with problems of my modded 2001 not starting lately. If the compression on that 250 is good check your CDI. I had good compression (120psi) fuel and spark by pulling the plug and checking when cranked over. Eventhough I have air, fuel, and spark the spark was at the wrong time and I can't get the 250 started. I'm buying a new CDI right now and hopefully the problem will be fixed.

 

Good thought..

Hay Nitro...what kind of engine mounds did you replace stock ones with?

 

Sisyphus2k2, I picked up the engine mounts from HPD.
HPD Engine Mounts

I haven't done a ton of riding lately but the rubber should be stiffer and keep the engine aligned with the belt better.

 

Maybe I'll give them a try..Thanks Nitro