600RacerX

I'm trying to help my friend with his sled, so I'll try and describe his problem the best I can.

He has a 98 MXZ 500 and was riding one day when it had a definite bog under heavy throttle. Then once up to top end it ran fine, but all at once it just died "as if it was blown up or something". Waits a few minutes later, and the thing fires right up and seems to run fine. Now since then the sled will only go 80 while still turning 8000 (when it used to go 90). The compression is fine and the belt is fine (according to him).

My thought was that it was two seperate problems. The first being he just overheated it or maybe vapor locked it (idk) and the second being definitely something in the clutching.

Any ideas?

jordandakota

Sounds like he could have a spark issue maybe? For the only going 80 instead of the previous 90, that seems like clutching to me also if he was still running the same 8,000 rpm's. My cousin had weak spark on his 98 formula 500 (basically the same sled) and it would bog out and almost die on occasion but other times it would run fine. I just learned about this problem the other day...go figure. He said they replaced the ignition coils and it solved the issue. It could also be as simple as bad plugs. My RXL would seriously only run about 25 mph once when I had bad plugs.

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1974 Arctic Cat Cheetah 340
Gonna be set up for ice fishing. Should be good for it's purpose!


Most snowmobile problems are caused by a loose nut connecting the handlebars to the seat.

skidoostud

I seriously doubt there's anything up with his clutches, It sounds like a spark plug issue to me. So I'd say buy a new pair, put em' in, and see what happens!

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Current Sleds-
95' ski doo Mach z 780 triple (stock)
98' ski doo formula sl 500 (Stock)
98' Arctic cat 440 Jag (studded)

Previous Sleds-
00' Mxz 700
1992 Ski doo Mach 1 (DG pipe)
1976 El Tigre 5000
1972 Arctic Cat Panther 440

"Ride em' till you can't feel your toes"

Spun222400

Could be running really rich, idk if the 98's are choke but mite be something to look at

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2010 crossfire 8 H.O. Sno Pro
2006 Crossfire 6(Wifes)
2000 MXZ 500(sold)
2002 Honda foreman 450(plow bike)
2005 Yamaha Banshee 350 (crazy)
2008 Yamaha Raptor 350 (wifes)

skidoostud

Take your plugs out and see how they look!

__________________
Current Sleds-
95' ski doo Mach z 780 triple (stock)
98' ski doo formula sl 500 (Stock)
98' Arctic cat 440 Jag (studded)

Previous Sleds-
00' Mxz 700
1992 Ski doo Mach 1 (DG pipe)
1976 El Tigre 5000
1972 Arctic Cat Panther 440

"Ride em' till you can't feel your toes"

600RacerX

ok, I'll be sure to tell ask him to check his plugs.

Any Mods wanna chime in?