I just wondered if you found anything out on your sled because my cousin just got the same sled and is having the same problems.
We have cleaned the carbs numerous times and the first time we found the piloit jets completely plugged. After that if the sled would sit and idle for a little bit when you went to take off it would bog and act like it was loaded up. We went through most of the jetting we could find and verified it was correct.
Main Jets 290
Piliot Jets 22.5
Needle was in the 3rd clip or middle clip
Inlet Valves were 1.5
Throttle Slide 4.0
We looked into the float setting and float inlet valves a couple of times. The float height is set correct. We did find the o-rings on the inlet valves to be bad and replaced them. Also found the vaccum hoses off the engine to the fuel pump to be leaking. The last thing we found was when he cleaned the piliot jets out with a torch cleaner he actually increased the size of them and we are ordering new jets to try that. I had a set of 25 Piliot Jets we put in and it seemed to help so we are hoping new 22.5 Piliot Jets cure it.
I was just curious what you found and the problems you were having with your sled?
Thanks for the help. I'll check my jets and see if they are correct. No I haven't figured it out yet. I had my dad ride it yesterday and we figured it was the pilot jets. It runs rich. When you pin it from a stand still It blubbers its way up to 5K rpm and then takes off. It doesn't bog and die. So it's not lean. On a normal sled if you pin it it will take off with in a second. Mine takes 3sec.
What are "o-rings on the inlet valves" that you talk about?
The way your sled is acting is exactly how is acts. If let it idle and pin the throttle it acts like it's loaded up, if you don't let it idle and load up it seems like it is good. The o-rings I was talking about seal the brass fuel inlet seat to the aluminium carb body. If they are bad it will leak gas around them. The other big thing we noticed was the vacuum lines to the fuel pump leaking where they attach to the engine. Like I said our next step is to get new 22.5 piliot jets since we think by cleaning them we took the hole size oversize. Keep me posted on yours and i'll keep you posted on ours. Also what number do you have your ignition box set on? His is on -1 but i'm not sure that is right.
Where do these vacuum lines attach to the engine?
I just got my sled 2 weeks ago, I didn't even know the ignition box could be set. How do you tell what setting it is on? The settings change the timing right?
OK, HERE IS THE FIX!
I changed my pilot jets from 22.5s to 20s. And bingo, She runs great! I didn't think it would be that easy but I guess a little jetting goes a long ways.
To anyone else out there, also check your choke plunggers to make sure they are set at the right height. They can get out of wack when you clean your carbs.
Thanks for all the help guys!