On the right track to cure idle hang?

Backwoods M Max

Backwoods M Max

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Joined
Mar 31, 2011
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New England
Just wondering if I'm on the right track. I started out with a 1700 rpm idle, but it was "cold" never really was able to get the sled to operating temp just by sitting on the dollies. Changed my drive belt and this new one might just be a ch longer with a bit less drag because the idle jumped to 2100. I went out for my first ride the other day and had a 4000 rpm idle hang, a shot of choke would drop it right down but it wanted to climb. I came home and pulled the carbs and added 1/4 turn to my idle jets 1 3/4 now. I went out this morning and it still had the idle hang, came home and added another 1/4 to bring the idle jets to 2 turns. I went out this afternoon and it still had the idle hang. I rode home and backed off the idle speed screw 3/4 turn and the idle came down to 1600, but the motor is absolutely at operating temp. Since it wasn't a partial warm up, but 15 miles of up and down logging roads I should now have a stable idle because it was set at operating temp? On a cold re start the sled will kind of chug along at a 1200 rpm idle but I guess that's just the nature of the beast to have it run right when it's warmed up. How is the 2 turn idle jets? Is that what most guys do to cure the ethanol blues? I'm thinking the 2 turns are ok the sled doesn't stutter from a dead hit, and the needle clip shims are both on the bottom in the middle clip for ethanol. Pulls hard all the way to wot with no flat spots. Pto plug is dark tan, ctr and mag are light tan, burn is at the bend on the ground on all 3. I think she's dialed in jus wanted to be sure about the idle hang. It's no fun having a sled that stalls all the time because of a low idle
 
I think you're on the right track. One thing that you should do is spray around the crank seals, carb boots, etc. Just to check for air leaks. 1200 rpm's is low I think. Your plugs sound good, how is the piston wash? Really need to check that in conjunction with the plugs to get the real story.How are your reeds? I didn't have really good luck with my VF 3's. Does the sled start normally? Is this something that just happened or has the sled been like this since you got it? Those MBRP cans sound great but it's a known fact that 2 stroked need back pressure to operate properly. If you've got the stock can, I'd put that back on just for sh*** and giggles . I've got a Viper and fuel screws set at 2 turns. Needles set a little richer. The fuel screws took care of my idle hang. My idle is set at 1500. You caught my attention when you said after you blipped the choke the idle went down and then right back up again. Did that go away when you brought the idle down to 1200?
Sounds like you know what you're doing. Keep us posted.
 
I did the carb cleaner trick the other day and it was fine. It was idling cold at 1700 so I think it was just climbing when the motor was warm. I cold started it this morning and to load it in the truck and it started second pull, it was idling at 1200 and as it warned up it was coming up. It was idling at 1500 by the time I got it in the truck. The important thin is that it doesn't hang now. When I let off the throttle it will settle down nicely from 3000 to 1700. When I got the sled last spring the idle was low so I brought it up, I guess it was just too much. I like the vf3's. The sled has much stronger mid range and the stumble is gone. The reed cages are shorter and have 3/16 spacers so I think the transfer port is really opened up. I think the only thing noticeable from the mbrp is it takes a little longer for the idle to come down than stock. Now that the idle hang is squared away I think she'll be good to go. I was really looking for feedback to make sure I was doing the right things to get the idle down.
 
The idle didn't go back up after the choke blip, it would stay at 2100 but just breathing on the throttle and it would rev back up. I really think I just had the idle set too high
 
I got about 45 minutes of ditch banging and hill climbing this afternoon. The idle still drops right down which is sweet. It will hang up near 3500 if I'm coasting down a hill, but you can tell its being pushed by the belt not singing along on its own. It drops right down when I stop.

There was about 6" of dense powder to play in, not enough to try carving but I got to see how well the new skis float.

Praying for snow
 
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