05 Summit 800 only runs at 6500

[Can-Doo]

I just bought a 2005 Summit 800 151. I took it out for the first time yesterday. It revs up to 7500-8000 when I hit it then it drops to 6500 and stays there at full throttle. If I go back to around 5000 for a while then hit it again it pulls hard up to 75 or 8 then back to 6500. It idles good and pulls real hard. In the deep snow it pulled down to around 4500. The engine is suppose to be stock with only the pistons replaced. Any ideas?

 

[Can-Doo]

Anyone have any ideas?

help please

 

[smokin09]

check the spark plugs if they are black and running rich the dpm might have somthing not connected. check the carbs and make shure the hoses that run from the carbs to the dpm are not pinched off cracked or unpluged. check and make sure that u have head lights and that ur guages work if not there is a resister under the dash that went bad. somthing could binding up in the clutch.

 

[Can-Doo]

Thanks, the headlights work and the guages work. It acts like it has a rev limiter shutting it down. Does it have a computer that controls the engine?

 

[ak]

did you check the air sensor on the airbox? make shure its plugged in.

 

[hymark860]

Check your RAVE valves. If they don't open all the way you won't reach max rpms.

 

[PaulWatt]

Exhaust valves, probably ripped bellows, by the sounds of it. The pressure pushes open the valve at first, but then they slip back down, dropping your rpm.

 

[JedInUtah]

What is your elevation?? What are your clutches set at currently?

Stock Primary? Any changes in weights springs? etc.

 

[Motley Doo]

You said that it acts like it hits a REV limiter, like it drops a cylinder? Check your DESS key, mine did the same thing last year, the little taped in star in the key fell out, but mines an 01'. I STILL fight the thing, now it does it at 3k, like once every five rides, so when you find another thing wrong, please, LET ME KNOW!!!!!!

You might also take it down to the Ski-doo dealer and let them diagnose the thing through the MPEM. Not sure if it would turn up anything, but possible!

 

[allrevvedup]

My thought is that either your secondary spring is weak letting it shift out too far or the primary spring is sacked out again letting it shift too far. I think you should clean the clutches and replace the springs. my .02