670 questions

[JHG]

A friend of mine just bought a 96 670 summit for his first sled. He only paid about 1000 bucks for it so he doesn't want to put a lot into it. We took it for a ride and it will rev to about 7200 rpms then fall back to about 5000. Even on a stand it falls back to about 6000 rpms.

I think the secondary spring is probably shot and not backshifting...sound about right? Any other ideas?

It also burned a full tank of gas in under 40 miles. The local dealer says the HAC system is probably screwed up and a new part for that is like $300+. They said just take it out and plug the hoses but we would have to drop jet sizes. Does anyone have any idea what jets to use for 6000-9000' with the HAC system bypassed? Sorry for the long post but I've never messed with a doo before.

 

[H20SKE]

First get the secondary off and clean it!! The springs sack out in about 1 season of riding, but my money is on the helix binding up and the bushings in the secondary are worn out too.

I would say to run 380's to 370's to start and do some pulls and check your plugs and wash.


H20SKE...

 

[ak]

370 380 are stock jetting with The Hac. I would remove the HAC and jet it similar to a MXZ 670 its the same motor without the HAC. Clean the clutches and rave valves also.