I cleaned the carbs and put it back together but I noticed when you rev it and let off the gas the rpms stay around 4000 and take a while to drop down to 12 to 1500 rpm. It never did that before. Choke and throtle cable are not tight. Any ideas? Does it have anything to do with the air pilot screw
bluemonster1
LIFE MEMBER ONLY ONCE!!!
was your fuel screws set up properly.You may have to open them up more to resolve the hanging up.
They call for 1 1/2 turns and I have them at 1 1/4 turns out. There is no bog when you hit the gas. It just takes more time for the rpm's to drop down at idle. They sit at 4000 then slowly creap down to 1500
I ran mine at 1 3/4. Try flipping the choke on and see if this drops the idle. If it does your idle circuit is too lean.
Yes it does drop it down. So you say I must change from 1 1/4 to 1/12 turns out
mod-it
Member
Yes, your idle circuit is lean. I'd try the stock 1-1/2 turns and see what happens. Do you know where they were set at before you changed them? If you do, and it ran good before, then set them where they were. Just wondering why you changed them, was it running rich before?
I thought it would help in making it start easier and run smoother from a cold start.
mod-it
Member
I've not heard of many sleds running under the stock setting unless bigger pilots have been put in. By setting them less turns open you've reduced the amount of fuel in the idle circuit, thus creating the hanging idle because of lean condition. As far as starting easier, the choke gives it more fuel to help it start when cold, reducing the amount of fuel will make it start harder (although the choke should cover this while it is on). Also risky in creating a lean condition when running at zero to quarter throttle. Perhaps it was set a little too lean before and needs to be opened a little more? Stein says he has to run his at 1-3/4. My Viper is cold blooded too, just need to let it warm up before really getting on it. Plus, running them very hard when cold can cause a cold seize, seen that more than once. I always cringe when I see people pull the cord and then take off at full throttle. I let mine idle for about three/four minutes when were about ready to take off, and then run it easy the first couple of miles while blipping the throttle to let it warm up good before jumping off the trail into the powder and running it hard. I know, it's hard to have the patience to wait before letting it rip, especially on the first ride of the season.
What kind of hard starting are you talking about? How many pulls to fire it up? Perhaps you have some kind of choke problem causing this, such as cable is set too loose so it doesn't open all the way on double choke, etc...
What kind of hard starting are you talking about? How many pulls to fire it up? Perhaps you have some kind of choke problem causing this, such as cable is set too loose so it doesn't open all the way on double choke, etc...