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Discussion Starter #1
I ran my new-to-me 99 SnoPro this weekend and have a couple of questions. It's not running like it should.
First it kind of hesitates off the line and then it feels like it shifts gears and rockets up to 6500-7000 RPM , but then starts stuttering and will only run at 7000 (about half the time, it does better with new plugs untill you stop and start again)and eventually it will open up and rocket up to 8000. It probably hesitates at 7000 from anywhere from a second (only a couple times) anywhere to maybe 30 seconds. Mostly happened from a stopped start, would do better from a rolling start. Also starts cutting out at full throtle after a while, slmost feels like a plugged fuel filter or something.
Also it's running lean. Changed out the plugs a couple times to make sure.
Now here's my guesses (and I'm no mechanic. This is my first sled in several years)  The hesitation off the line then the shift I'm guessing it might have a dual or Tri helix in it, because the guy said it had a clutch kit in it.
The 7000 RPM thing I'm guessing is the power valves are in need of some cleaning and maybe even the update. I'm not sure if the update's been done to it.  
Also I switched oil from whatever he was running)I forgot to ask) It was red and had a sweet smell,  to Amsoil Synthetic green oil.
I need to know how to turn up the oil so it's not running so lean. Hopefully I didn't hurt the motor any. My friend said I probably didn't. We ran about 80 miles.
Other than all that, it was a great ride!
I would appreciate any of your input. If you could help, I'd greatly appreciate it.
Thanks in advance.
 

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I have the same problem with my '99 sno pro just not as bad.  I have found that it is from a rich mixture not lean.  some times it will not go off the line if you back off and roll on the throtle it will go.  this only happens if i let it idle. so i don't let it idle.  it doesn't happen as much when it is colder (around 0 degrees F) if you run in warmer conditions this might be the problem.  If  you think it is lean then i would check your jetting and oil pump settings.  I run 310 main jets in mine which is plenty rich for me good to -10 F.  I would also check the power valves. make sure they are clean and move freely.  The updates will do nothing for performance unless one is broke (there would be a big difference then).  If possible I would try to check with the previous owner to see if they were updated just so you know.  mine also had worn clutch weight bushings which made it shift slow.  red oil that had a sweet smell was probably Klotz techniplate.  this is a good oil but so is Amsoil I run amsoil.  the previous owner if experienced could have adjusted the oil pump to the different oil flow. also make sure your plugs are BR10eya's unless you run it slow alot.  but then you shouldn't have got a sno pro.  you can also do a compression check it should be around 120psi.  also check that your timing adjuster   is on 0 or less unless you run raceing gas.  and i would keep it on the cold setting.  this all I can think of.  So I would first check jetting, the oil pump and the power valves.
 

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sorry forgot some things. changing oil types should not affenct the way it runs.  but to adjust the oil pump you losen the adjusting nuts on the cable, so the markes on the pump arm lin up with the line on the pump. the first line is at idle and the second line is at WOT. It is hard to get to the oil pump to make these adjustments.  But if you take your carbs off, which you should do just to see how it is jetted, then at the same time it will be alot easier to check the oil pump.  with the carbs off you can also take your reeds out and check those for damage. another thing, the sled will run like crap when it is snowing or if you are going through deep snow and jumping drifts, because the snow will clog the air intake. be carfull when this happens because you can burn it down if snow gets in the motor. a snow screen filter (like a pre filter) that gos on the hood will help.
 

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Discussion Starter #4
Thanks Fire Cat!  I really appreciate you taking your time and sharing your knowledge.  
My friend also owns a 99 snopro and I'm getting together with him this weekend and we'll go over it - check the compression, jetting and oil pump. Thanks for letting me know how to turn up the oil pump, because neither of us knew.
Thanks again.
 

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Discussion Starter #5
Fire Cat:
We looked at my sled this weekend. It's got good compression and the updated valves that are fairly clean and the reeds look new. Heard from someone that synthetic oil makes it hard to read the plugs, that must be right, because it's running really rich. Only thing is, my friend didn't know how to re-jet, so I'll either have to learn myself or take it to someone who knows how to do it. The oil pump may need to be turned down too, but we didn't mess with that either. Might be fixed with the jetting.
Thanks again!
 
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