1975 Polaris Colt problems

[mn_bowhunter]

Hi all. Hopefully you can help me out with this. I have a 1975 polaris colt ss that I cannot get to run correctly. I rebuilt and synced the carbs after putting on a new throttle cable. The sled has been sitting at least 10 years. It has 120-130 lbs compression and seems to have decent spark. The sled will idle great, but when I give it gas it will only rev to about 4000 rpms, and when I hold my hand near the carbs fuel and air are coming back out. Exhaust gas slowly rolls out, so maybe the exhaust is plugged. The other thing I was going to check is the points. Any other tips and things to check. It also occasionally backfires when dying out so could it be timing related?

[leech~~]

Hi all. Hopefully you can help me out with this. I have a 1975 polaris colt ss that I cannot get to run correctly. I rebuilt and synced the carbs after putting on a new throttle cable. The sled has been sitting at least 10 years. It has 120-130 lbs compression and seems to have decent spark. The sled will idle great, but when I give it gas it will only rev to about 4000 rpms, and when I hold my hand near the carbs fuel and air are coming back out. Exhaust gas slowly rolls out, so maybe the exhaust is plugged. The other thing I was going to check is the points. Any other tips and things to check. It also occasionally backfires when dying out so could it be timing related?

I would check the air box and take off the muffler and make sure it is clear. I have worked on two sleds over the years of friends that had sat for a few years. One had the air box packed with a mouse nest and the other had the muffle packed with cat food. Both of them would start but not pick up any speed past half throttle, smoked bad and backfired. You have to take the muffler all the way off and shake it to make sure. Good luck!

[Surface Tension]

The swirling fuel at the carbs throat and sneeze usually means lean by way of too much air.

Double check your carb flanges for cracks.

Could be the engine not breathing and if your lucky a mouse nest in the muffler.

Other then that and considering the year leaking crank seals will do this.

[mn_bowhunter]

Got lucky and had an exhaust system packed full of acorns and hair. A little time with the torch on the outside to begin burning the contents and some wire got it clear. She revs to 7000 fast, hopefully we get some more snow and cooler temps so I can get it out for a ride.

[Surface Tension]

Good to hear.

I had a wheeler spit sun flower seeds out the exhaust for a few minutes.

[leech~~]

Got lucky and had an exhaust system packed full of acorns and hair. A little time with the torch on the outside to begin burning the contents and some wire got it clear. She revs to 7000 fast, hopefully we get some more snow and cooler temps so I can get it out for a ride.

Great to hear, it sounded just like the issues I had with the others sleds I worked on. Glad to help!