i have an old 1987 250 polaris cyclone atv 4 wheeler. it runs great and has tons of power, but it is aweful to try and start. no electric start so it's no fun to yank away at. good gas and oil, 90 some psi on compression test, spark looks good, cleaned carb out and adjusted choke and throttle. it takes starting fluid and alot of pullin to get it started. checked tube to head, changed hoses, swapped spark plugs and it didn't seem to do anything for it. even after driving it for hours it still sucks to start. any ideas anyone? i'm out of ideas i welcome any thoughts about it.

just about got to be in the low idle adjustment try finding the factory specs on carb settings and then adjust it a little rich
Yamaha Honda Can-Am Kawasaki and all others are the way in but POLARIS IS the way out....

i found in the book i have where the compression is 115 psi minimum. so i pulled the head and the jug off and took the parts to a friend with a machine shop. the piston is good but standard size and the jug is bored .010. the rings on it are standard size so maybe that is the cause of the problem. i honed it out and got gaskets and oversized rings. i'll put it together and see what happens.

Your on the right trail, you need at the very least 100 PSI of compression for it to start easily with the pull start. Also be certain the throttle is wide open when you do the compression test or you will get a false reading. If you liked the power with 90 PSI you should have a huge smile on your face when you goose the throttle with a fresh top end rebuild after a careful break in period.

Happy trails,
Curley

i ended up with it bored to 20 thousanths over stock and a rebuild kit. put it together and now it starts on like the 2nd or 3rd pull and has more power than ever. i adjusted about every thing i could while waiting for parts etc and we are already having a blast with it. it sure runs, starts, and rides nice now for an old wheeler. i had bought some new rings and gaskets for 10 thousanths over that i didn't end up using so i am going to go through one of the other wheelers we got around the place and freshen it up as well. it is pretty easy once you have done it a few times and ended up costing me about $125.

glad to hear it worked out