Hey new to the site and looking for some help. I have a 87 Indy 400 L/C it won't go above 50 mph and it's really boggy when wide open. sometimes worse than other times. No matter what i do to it. I have cleaned the carbs again and again put it back to factory jets (at least from what i have read) (220 main/35 pilot) it should be rebuilt because the compression is 100 psi and 90 psi the other I'm lost I guess my question is could the low compression cause this? I feel even with those numbers it should run better. What else could cause this?
Plugs are a dark brown. I think I'll pick up a new set of rings and throw them in this weekend. hopefully that will solve my power issues also going to replace all the gas lines just for sh*ts and giggles. what is the proper way of making sure the rings seat before going crazy with it again? i was told a tank of premix and oil injection and not to go over half throttle is this correct?
OK, well i took a little video and uploaded it to YouTube the quality is pretty bad because i took it from my phone while trying to drive the most important part anyway is the beginning you can see me punch it and nothing happen at all i know it need a rebuild but i'm sure it has more problems than that because with the same PSI the motor had been doing 76 mph.
Engine sounds OK, clutches are the most neglected part on most sleds, particularly older ones.
Do this test;
remove belt, with a marker draw a straight line on both units from center to outer edge.
Put belt back on and run it. Then see how much of the lines are worn off.
That sounds like clutch problems to me. That could be a broken primary spring, or a binding secondary. Even a really bad belt could make it act like that. Hold off on a top end rebuild until you have clutching and carburetion sorted out.
I totally agree that its your clutches. 26 year old springs will do that lol. Kinda sounds like the secondary is either broken/worn/not preloaded. I'm sure once you open the secondary you will also find more wrong than that. Best plan of action would be to refresh both clutch springs and make sure you preload the secondary when you put it back in.
"Do not go where the path may LEAD, go instead where there is no path and leave a TRAIL"
Originally Posted by Rubi
Nobody on this site likes Ski Doo except Dirty Harry, and he's better at making babies than buying or fixing sleds, so you don't want to listen to him.
figured out it wasn't getting enough gas pulled the fuel pump crud in it and the pulse section was full of watery oil... saw air in the lines when it was running too need to add more gas to see if it's just a low tank or bad lines for that. I agree that the clutches should both be rebuilt but i have no way to pull the primary any tips?
All the stuff you can do to the primary without expensive specialty tools can be done in the sled. Put a Quickgrip clamp on the clutch to hold the cover plate on while you remove the cover bolts. Carefully release the clamp because the cover will be spring loaded. Check the fiber bushing in the cover plate, and inspect your spring. Unless you're on the super-tight budget plan, have a new spring on hand to throw in there. If you don't want to buy a new spring, at least inspect the old one. They do break. Make sure all the rollers that the weights hit are free-spinning. Make sure the pins that hold the weights allow the weights to swing freely. Wiggle the weights back and forth to make sure there isn't enough slop to allow the weight to swing off the roller.