Looking for some advise (process of elimination) on a '00 Trailblazer 250. It is new to me and is hard to start but hasn't always been. New plug, carb kit by me, carb cleaned again & again by me, fresh fuel. Cold (70 deg F) seems easier but when warm hard to start. Pull start broken so using electric and usually the battery gets low and I use a jump. That spins faster and depressing full throttle usually gets it to go. I can put a little mix gas into the cylinder and quick to fire but quicly dies. When running seems to run good although a little sluggish for quick takeoff. Ran the other day for two hours (Plug greyish brown), ran out of gas, then refuled and cranked and cranked then jumped, turned over faster and started. I removed the intake boot(bolts not terribly tight), no cracks, o-ring seemed ok and no signs of short circuiting the carb. Don't know much about the choke, don't see how it works and doesnt seem to make any difference engaged or disengaged. Where to start? Fuel, Spark or both.

Thanks for any help.

Rob:

 

Check the compresion!Sounds like it may be time for a rebuild

 

for a quicker start just remove air filter and cover intake with your hand for about 2 revolutions, should start immediatly if it doesn't you have other issues. sounds like low compression or broken piston skirt. remove carb and look at piston skirt while you turn it over, if its broken you won't get the cylinder to seal so it cannot draw air mixture into crankcase.

good places to start