Hello, I am new here and was hoping for a little help. I have what i believe to be a 1998 polaris xplorer 2 stroke 300 4x4 (but cannot say for sure, cant find definitive numbers). When I got it a few years ago it ran fine but would always die at idle. I ignored it and just gave it throttle anytime i was using it. I would also have to start it by using starting fluid in the air box, giving it throttle and then it would start and run fine. I recently rebuilt the carb but the idle problem continued. Now i cannot get it to fire at all, even with starting fluid. cold compression is 110 , and i have spark. i premix fuel, so the oil line is empty but still connected. Starter is locked up so i use recoil starter. Any ideas? Thanks in advance

 

shoot the SF down the plug hole & re-try...often, after carb work, folks have a hard time starting their atv's...so they shoot SF into the air stream...that doesn't produce a rich enough condition...

 

Compression is getting to the low end. If you have to use ether to start one it doesn't have enough vacuum to pull enough fuel on its on when cold. This can be because its time for a new top end ,crank seals or usually both.

 

Thank you both! I sprayed some starting fluid into the cylinder directly and it fired up for a second. What does this mean? Still a top end and crank seals causing this?

 

Crank seal behind the drive clutch was the worst to cause problems like this.I've seen some that would even pop out. You can start there first and replace it and see if it solves the problem. If it doesn't and you have good spark, a clean carb, good fuel supply,then it's probably time to check into the top end.

 

I'd say fuel delivery...carb needs a cleaning...if it fires on SF, then it usually just needs gas to get to the plug...Make sure you check your reeds...if it has them...

 

Thank you, I am thinking of ordering a brand new carb. Would a 30mm mikuni carb with these specs be correct:
Bore Size: 30mm
Spigot Mount: 40mm
Main Jet: 250
Pilot Jet: 40
Needle Jet: P-5
Throttle Valve: 2.5
Jet Needle: 6F5
Air Jet: 2
Mikuni Part#: VM30-83




also, when I turn the motor over with the pull cord I can hear a hissing sound like air is being released. sounds like it is coming from near the drive clutch. Could this be the crank seal leaking on that side? I have ordered the new seals and just trying to troubleshoot as much as possible. Thank you

 

Yes the hissing could be the crank seal. Don't buy a cheap Chinese carb when you can rebuild these easily.http://www.ebay.com/itm/POLARIS-XPRE...9TKJbg&vxp=mtr