MM clutching help

Backwoods M Max · Nov 17, 2014

I figured this may be a long shot trying to get help with a sea lever clutch setup on here but I figured it's worth a shot. My 2002 mountain Max has been extended to a 151. I ride in New England and the elevation ranges from 1500' to 4000' at the most. Last year I was running a w-w-w primary with 8cr weights 13.3 heel 17.2 tip rivets. Gearing is 20/39 (has reverse) on 8 tooth anti ratchets. Secondary spring was a silver at 60 wrap on a stock 43 degree helix. The setup just didn't work. In deep snow when it was time to pin it and power through I was seeing high 8000 / low 9000 rpm with only half up shift on the primary. I have asked around on Ty but not really gotten good advice.

The guys are getting hung up on my final drive ratio and driver size instead of explaining to me how to get full shift out when I pin it and need the track speed. I'm looking for advice on how a mountain sled should be clutched and I have some components on hand to test with.

For this winter I will have 17.2 rivets in both holes and the following primary springs available to me. W-w-w, y-w-y, w-s-w and w-g-w. I am going to start with the w-g-w. I also have a silver, green and red secondary springs to play with. Overall condition I'm trying to remedy is over rev and low track speed without complete shift out.

Thanks all!

Givemeaboost · Nov 17, 2014

If you want track speed with a 151 and about 110 hp you need to gear it down. I used to run a 136 with powerinc pipes and a few other mods with a 18-42 gear ratio. It ran good at 8000 ft. If you go to an 18 tooth gear you need to run the chain tight or it will tear off the teeth.

Ken.........

Backwoods M Max · Nov 17, 2014

I use to get full shift out before I did the track extension.

The stock calibration for sea level is based around 23/40 which I'm nowhere near with the 20/39 I have now. Unfortunately I can only swap a 13.3 for 17.2mm rivet and the weights are maxed out for tuning. At that point I think I'm down to playing with springs to make it work, just need some pointers in the right direction.

SRXtreme · Dec 1, 2014

Backwoods M Max said:
I figured this may be a long shot trying to get help with a sea lever clutch setup on here but I figured it's worth a shot. My 2002 mountain Max has been extended to a 151. I ride in New England and the elevation ranges from 1500' to 4000' at the most. Last year I was running a w-w-w primary with 8cr weights 13.3 heel 17.2 tip rivets. Gearing is 20/39 (has reverse) on 8 tooth anti ratchets. Secondary spring was a silver at 60 wrap on a stock 43 degree helix. The setup just didn't work. In deep snow when it was time to pin it and power through I was seeing high 8000 / low 9000 rpm with only half up shift on the primary. I have asked around on Ty but not really gotten good advice.

The guys are getting hung up on my final drive ratio and driver size instead of explaining to me how to get full shift out when I pin it and need the track speed. I'm looking for advice on how a mountain sled should be clutched and I have some components on hand to test with.

For this winter I will have 17.2 rivets in both holes and the following primary springs available to me. W-w-w, y-w-y, w-s-w and w-g-w. I am going to start with the w-g-w. I also have a silver, green and red secondary springs to play with. Overall condition I'm trying to remedy is over rev and low track speed without complete shift out.

Thanks all!

Are you piped? IMHO the 43 is too shallow. Try a 47 they came stock on alot of sleds. This will force the upshift. The primary weights primary use is RPM, the shape of the curve changes shift characteristics. The primary spring controls engagement and shift rate. the W-W-W is 45, 2.5, 119 to lower shift rpm you need a spring with a lower rate(total force) so a B-W-B is 45, 2.0, 111. This spring will engage the same but shift sooner.Your W-S-W will give a lower engagement and shift similar to the B-W-B. This is a starting point, give me some feedback and I will try and get you closer to what is needed.........SRXtreme

Backwoods M Max · Dec 3, 2014

Thanks for the feedback. That is something I can really use! Some other responses I have gotten have been all theory with no help suggesting what parts to look at. No pipes, single pipe with race can. I will start out with the w-s-w and maybe even throw in the w-g-w just to see what it does. I picked up a 51/43 helix from an rx-1 for short money so I will try that. How do you tune the secondary on a multi angle helix? I know the 51 will grab belt fast and the 43 will back shift as the track starts to load again when I pin it. I have a red, green and silver spring to play with.

I have my stock 8cr weighs set up with 4.5g rivets in both holes and I picked up a set of 8dn-20's for a song brand new. I figure I can start playing with the 8dn's of I need to and only weight the heel to start with.

My engagement last year was around 4500 rpm which was way too high. There was a lot of hole digging trying to climb away from a dead stop. If I can get down to 3500-3800 I will be psyched.

willinwillys · Dec 3, 2014

Hey man I have 4 Yamaha 2-strokes I run 8dn-10s or 20s and like a straight 45 to 47 helix and love it.

SRXtreme · Dec 4, 2014

Backwoods M Max said:
Thanks for the feedback. That is something I can really use! Some other responses I have gotten have been all theory with no help suggesting what parts to look at. No pipes, single pipe with race can. I will start out with the w-s-w and maybe even throw in the w-g-w just to see what it does. I picked up a 51/43 helix from an rx-1 for short money so I will try that. How do you tune the secondary on a multi angle helix? I know the 51 will grab belt fast and the 43 will back shift as the track starts to load again when I pin it. I have a red, green and silver spring to play with.

I have my stock 8cr weighs set up with 4.5g rivets in both holes and I picked up a set of 8dn-20's for a song brand new. I figure I can start playing with the 8dn's of I need to and only weight the heel to start with.

My engagement last year was around 4500 rpm which was way too high. There was a lot of hole digging trying to climb away from a dead stop. If I can get down to 3500-3800 I will be psyched.

The 51/43 should work pretty good, Try it with the spring I mentioned earlier.The 8DN's will load your motor too much, it will bog. If you want to try them, start empty. Check for out of the hole performance first and engine RPM. The heel hole will load the motor more. The tip hole use it to adjust top end and final RPM adjustments................SRXtreme

SRXtreme · Dec 4, 2014

OH ya get some PIPES!!!! wake that thing up........SRXtreme

Nebraska700MM · Jan 4, 2016

So what did you find out? Haha

Backwoods M Max · Jan 17, 2016

I was tired of messing with the yamaha weights and probably would have saved a lot of money if I had just bought the heel clickers first.

I ended up with the heel clickers kit and they are set up for the non piped sleds. it has the long bolt and either 3 or 4 washers in the shoulder. The engagement is still a little high it grabs around 5000 but I did it late season and things weren't warn in yet. The weight pivot bushings were a little tight on the clutch shafts and the spring still wasn't broken in yet. I only got a few quick rides in it last year, waiting on snow for this year still. putting on the primary cover with the heel clicker spring is a pita though. you either really need a primary spring compressor or have to go get much longer bolts and step them down in 20mm increments because there is no way you are going to compress that spring enough by hand to get the yamaha cover bolts started.

I like the way it shifts, hits real hard and works great with my current gearing. I'm around 8600 rpm wot and the thing wails and isn't falling off the pipe which is great too.

I had a bad plug when I was trying to tune as well that didn't help my problem. I had a dirty tors switch that I was trying to work around for the start of the winter and hitting the rev limiter from a wot pull killed a plug. It would still idle but was giving a weak spark at WOT which through in another variable trying to tune my peak rpm's. Once the heel clickers were in the problem became real apparent. 3 new plugs and cleaned the tors switch and things were right where they were suppose to be.

lonerider1 · Jan 20, 2016

Glad you found the prob. No disrespect but if SRX Extreme talks you might elect to listen. Very experienced and intelligent.
p.s. I've got a bone stock kinda 162 MM that is a lot of fun at 4k or 13k. Just a little tuning goes a long way.
Ride on.

Ford428CJ · Feb 19, 2016

Backwoods M Max said:
My engagement last year was around 4500 rpm which was way too high. There was a lot of hole digging trying to climb away from a dead stop. If I can get down to 3500-3800 I will be psyched.

I run a 141 crap track... My engagement is about 4200~4300 and feel its perfect! Light throttle and I dont get stuck as easy. I would think 3500 to 3800 is a bit to low. JMHO

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MM clutching help

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