mtn viper questions???

M

mtnviperbam

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Nov 22, 2008
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milo,maine
i just bought a 2003 mtn viper it was all stock and would only rev..8500-9000 before i put a snostuff can ,boysen reeds just the reeds,and reed spacers and now it is maxing out the tach at 10,000rpms up on a stand do i need to jet it and if so anyone know what jets to go with? and do i need to do clutch work?

:2strokes:
 

Dont know much about it but that seems like some excessive reving to me... I thought you should be looking in the 8100-8400 range. But like I said, I dont know much about it.
 
i dunno but i dont really wanna blow it up... im wondering if its to lean and thats why it is turning up so hard?
 
Check the plug color and piston wash. Not sure if you can check those unless you get out and run it though. I havent seen anyone doing after running it on a stand but it should give you something to go on.
 
Are you running it without the belt on? If not, does it have the right belt? There is no way that the clutches should have enough load to keep from quickly shifting all the way out on a stand. Generally you can not reach full rpm on a stand in stock setup. Maybe it is geared down, or maybe the stock gearing of the mountain setup allows it to overrev when fully shifted out on the stand. Are you holding it WOT for very long?

I also question whether you created an air leak when you changed reeds and spacers.

The stock Viper engine works real well with stock reeds and no spacers. There is much posted here on that topic. Aftermarket reeds come into play when you pump more air through them than stock.

Look for a response from Mrviper or Turk . . .
 
You want to be at about 8,500 rpm unless you do triple pipes like slp. I only rev to 9,000 which is correct for my set up. Something is not quite right. Post specs on clutching set up, carb set up, gearing and etc.
 
It is impossible to set up jetting/clutching from reving on a stand. I always thought it would over-rev without a load, but just recently learned that it will usually under-rev. At any rate, every good tuner out there has always said you have to run it on the snow to see what it is really doing. Like akmntviper said, your target is 8500 rpm. Usually you'll want to see about 100 rpm over your target on the trail, once your in powder the extra load pulls it down right where you want it.

By the way, what elevation are you riding at? Weight in the arms has to be changed the higher you ride. Stock set up is notorious for over-rev.

Anytime you change your air/fuel mixture in any way, you'd better check your jetting or risk a burn down. Most manufacturers of after market goodies will be able to give you a recommendation to get you close. If you want the best performance out of your sled, plan on riding it and then going back and fine tuning. Usually more than once is required to get it "perfect".
 
i would not "rev" it on a stand as this does not tell you anything about the sleds performance. check jetting and clutch specs for your altitude, then ride it and see where you are at.
 
well i guess im gonna put it all back to stock minus the can because i sold my stock can ....anyone wanna buy some reeds and spacers??
 
mtn viper bam said:
well i guess im gonna put it all back to stock minus the can because i sold my stock can ....anyone wanna buy some reeds and spacers??
Click to expand...

I have a never used, brand new take off stock can I'll sell you For $40 Plus shipping if you can not get it to work with the existing can.
 
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