Factory Carb Setting's - Snowmobile Forum: Your #1 Snowmobile Forum

newrider · 09-10-2006, 09:34 PM

Have a 95 550 and 580 EXT. Rebuilt carbs on 580 and would like to know what the factory setting are for Throttle Stop Screw and Air Screw and Pilot Jet 45. Pilot jet was set all the way in on both carbs. I set all screws as they previously were and matched them turn for turn to my 550. So I think I'm OK but would like to check with someone if anyone out there knows.

Also have a excesive oil/smoke problem. I think I have it narrowed down to the oil pump as there is a inch of slake in the cable. Any suggestions are appreciated.

Thanks,

Troy

**smallengineguy** · 09-10-2006, 11:04 PM

Air bleeds should be 3/4 to 1 turn out. Idle screws should make it so when the track is off the ground, it just starts to turn, but doesn't actually spin. Is the lever on the oil pump returning all the way down? Sounds like it's stuck.

BC_Dan · 09-11-2006, 10:33 AM

Like SEG said, 3/4 to 1 out on the air screw. If you have to screw it all the way in to make it run right, the pilot jets are probably being restricted (dirty), the pilot jet passageways are gummed up, or you need to go to the next larger pilot jet. I'm guessing the first two...

newrider · 09-11-2006, 11:34 AM

Oil pump is not stuck. I was thinking that might be it when I saw the slack in the cable, but it seams to have the correct range of motion. Is there any other ajustment on the oil pump that would make it pump so much oil. It just smokes like crazy and does not want to idle at all.

So should the pilot jet be screwed all the way in as I found it or 1 turn out also? Sorry, I'm new at this.

**smallengineguy** · 09-11-2006, 03:01 PM

It may not be oil, it may be the chokes stuck open and won't close all the way. When it's running, does opening the choke make it worse?

newrider · 09-11-2006, 06:07 PM

I can't get it running good enough to see if the choke makes a difference or not. I had a lot of rodent crap literaly in the engine compartment. I'm going to check the air box and the exaust. But I don't think that would affect the problem I'm having.

BC_Dan · 09-12-2006, 12:15 AM

Stock setting is one turn out from lightly seated and adjust 1/8 turn in or out at a time until you get best (fastest) idle. Shouldn't be in more than 3/4 turn from lightly seated; if it is, you probably have some cleaning to do.

Some oil smokes more than others. Cold engines smoke way more than warm engines. An engine running in the summer jetted for cold will be running way rich. All of these things can cause you to have a lot of smoky exhaust. You will probably have to wait until it gets colder to get it fine-tuned, but it should still run. I have a 440 Polaris; when I purchased it, it was set so rich that I could not even drive it onto the trailer. To help initially, I dropped the needle (raised the clip) one notch to lean things up. It was pretty remarkable how much that helped. If you do that, make sure you put it back for winter...

newrider · 09-12-2006, 11:13 AM

I havn't tried that. I running out of things to check.
Thanks for the info.
Troy

newrider · 09-13-2006, 12:00 PM

Raised the clip and still have the same problem. I can occasionally get it to idle for 30 seconds to a minute. But if I even touch the throttle it dies immediatly.?.?!

**smallengineguy** · 09-13-2006, 12:11 PM

Have you checked to make sure the fuel pump is OK, and the line from the engine to the pump isn't cracked, etc.