Slippage in the scondary

sifton

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Joined
Aug 24, 2006
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219
Age
57
Location
Manitoba, Canada
I have the belt slipping in the secondary as the engine rev's and the secondary does not open all the way. If I feather and play with the throttle, it will shift out. Once that is done, it then works properly. Just seems to do it when I first start my ride. Any thoughts on what my issue is?

2000 M Max-151"- gearing? I think it is 23/40....
 

What did you do to "overhaul" the secondary, so we know what all is new or has been checked?
Not much to a secondary. Spring, can get weak or "sag"; tension can be adjusted by adjusting which holes the spring sets in; helix ramp buttons wear and get badly worn and/or notched; 3 wear bolts on the very back of the clutch that wear, they are for setting belt deflection, although if they wear it causes the belt to sit higher and many times squeal at idle...belt too low in sheaves is like trying to take off in second gear (belt deflection, the belt should sit even with the top of the sheaves or up to 1/8" above).
Belt can also get worn too thin and cause the same second gear takeoff kind of situation. Belt can also get spun bad enough to really harden the edges where it rides and ruin how well it will grip.
Sheaves should be cleaned well with a green scotchbrite pad. Just warm soapy water, don't want a solvent that will not come off and leave a slick film.
Could also be something else binding up that causes it to slip until it is broke free. You should pull the belt off, raise the track off the ground and turn everything by hand to see how freely it moves. If it only does it after it has sat, mimic that situation when you check for everything to move freely.
 
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Ramp buttons and bushings were changed- the 3 bolts were changed prior. Scotch brite was used to clean.

I think I might be blaming the wrong clutch! I rode again, and looking closer after this happens, I do see some belt residue on the primary sheaves. I cleaned and tried again and the same results. But like I said, ride it a bit and all seems fine...

Primary was also rebuilt last year, but spring was not changed. I have a Heel Klicker kit and the red spring in it.
 
Oh geez I shouldn't have missed that...good catch Vincent.

By comparison, my 144 Viper has 21/40, for a ratio of 2.14 with 8 tooth drivers.
Sifton, at 23/40 with 8 tooth drivers you are at a 1.96 ratio with a longer track than I have. I believe Mnt. Max's were a 141 stock? I wonder if someone put a 151 on but then didn't gear it down.
So it struggles to grip well with that tall of gearing until the belt gets warmed up a bit I'd say.
With a 151" you want deep powder performance. If you play in powder a lot or hill climb in powder you probably know what your peak rpm is and what track speed you maintain when wide open in deep snow or climbing? Best for that is maintaining high track speed when it is under all that load. I think you'll want to be at around 21/41 or so. You'll have to then play with clutching after gearing it down.
 
The Tech pages actually show that stock gearing on a 2000 MM 700 was the same as what I have, 21/40. If it was changed to 23/40 that doesn't make a lot of sense unless the previous owner was a top speed lake racer type person.
20/40 would put you at 2.25 to 1 and 21/41 would put you at 2.20 to 1. I personally would start with the 21/41 and see how it does. I like to shoot for about a top speed of 75-80 mph on a mountain sled when deep snow performance is desired. Mine will do about 85 on the top end and I could probably benefit from dropping gearing a bit too. I currently see the speedo bounce between 49-51 mph track speed when climbing in deep snow.
It's all about track speed in deep snow.
After gearing it down it will need some clutch tuning. You'll have to see what peak rpm you are getting after changing the gearing and then more than likely add some tip weight to the primary arms.
 
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The Tech pages actually show that stock gearing on a 2000 MM 700 was the same as what I have, 21/40. If it was changed to 23/40 that doesn't make a lot of sense unless the previous owner was a top speed lake racer type person.
20/40 would put you at 2.25 to 1 and 21/41 would put you at 2.20 to 1. I personally would start with the 21/41 and see how it does. I like to shoot for about a top speed of 75-80 mph on a mountain sled when deep snow performance is desired. Mine will do about 85 on the top end and I could probably benefit from dropping gearing a bit too. I currently see the speedo bounce between 49-51 mph track speed when climbing in deep snow.
It's all about track speed in deep snow.
After gearing it down it will need some clutch tuning. You'll have to see what peak rpm you are getting after changing the gearing and then more than likely add some tip weight to the primary arms.

Thank for the info. Since we have next to nothing up here for snow this year, agian… I am going to shorten this sled up.
 


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