hey guys it's been a while since i logged in. nice to see every one is busy writing forums. i actually am swamped as i'm now the G.m. of Peak Motorsports in cheyenne Wy. so anything i can help any one with please email DanV. at Peak motorsports.com... and i will try to log in here more frequently... anyway one of my technitions is working on a 00' polaris 250 explorer. it ran fine until he washed it. now it cranks but will not start. we have a book and have tested all the safety swiches etc. it has 98psi compression, good spark, went through carb. has fuel flow, we even tried starting fluid and it won't even fart. we disconnected the notorious black wire and still nothing... please help... thanks danatack.

 

Think the 98 pounds of compression is the key to the problem. Should be at least around 120 or so to run properly. Probably time for a new top end,BUT being 12 years old now best to do a complete rebuild! I would check the rod for play up and down and any bearing noise as you roll the rod around. If the customer only wants to do a top end, I would emphasize that there is no guarantee on a machine that old that the bottom end would hold up. I've been down that road and learned pretty quick after being snake bit on a couple engines that I THOUGHT would be okay with just a top end. Good luck. OPT.

 

Forgot Again! It's also possible that you could have popped a crank seal(particularly the one behind the front clutch) if it was running ok before you washed it. If the seal pops out or started leaking badly could be part of the problem. Has to have bottom end compression also for the gas/oil mixture to atomize properly. Have had that happen before. OPT

 

Hey thanks, being this high in cheyenne wy. we need higher compression. what you said makes perfect sence, and i guess i was in denial... lol. we got it to run but it takes a lot to get it running. thanks again. i will est. a engine O/H.

 

i have a 2000 polaris explorer 250 4x4 ,has 120 psi compression,fuel, and spark,but still wont start

 

it was flooding,so i cleaned the carb,i have tried starting fluid but nothing, doesnt even try to start, im going to look at the reeds, any info would be greatly appreciated,thanks struggling on this thing

 

You don't have reeds on this model. If you didn't replace the carb needle and seat,plus replace the float arm and pin if worn,plus check the float arm setting could be the problem of getting too much fuel. 120 psi should be enough to crank it. Eliminate the carb as the problem first,if still fouls plugs could be loosing bottom end compression because of leaking crank seals. OPT

 

wouldnt it at least try to fire even on starting fluid with bad crank seals,nevr worked on a polaris before, its getting aggrivating

 

Even starter fluid may not help if the seals are bad or the crank case is full of gas. Try draining the 10 mm drain bolt at the bottom of the engine to see if the crank case has gas in it. If gas drips out,let it drain for awhile,replace the bolt,hold the throttle WIDE open without the plug in to clear any excess fuel,then see if it will crank. If it does crank then I would check out the carb again and replace the needle and seat. Also on these models make sure you turn the fuel valve off when not in use. Will eliminate any future crank flooding from the carb. If none of this helps then I would proceed to replace the crank seals then see if it runs. 120 psi compression should be enough if the seals,carb,etc are ok. Plus excess gas in crank case can cause it to show more compression than it really has! After you eliminate any possible gas in the crank,check the compression again and see if it's lower than 120! Could be time for a top end? OPT

 

ah hah, there was about 8 -10 ounces of fuel in the crank case ill let you know what the results are from the 2nd compression check i appreciate it OPT