Nytro supercharger clutch weights

[TPAY243]

Going to be clutching my buddies supercharged Nytro. He wants to keep stock secondary for now(save some money)or i would just order a complete kit. I want to use STM adjustable primary weights. What base weight should I use the 50 or 60 grams and should I use the trail or turbo ones. It is a 2012 FX with MPI 180 kit shooting for 7 psi of boost. Any help of weight placement on the cam would be greatly appreciated. Am I going to be beating a dead horse here doing it this way I can try and talk him into a complete clutch kit but money is kinda tight right now.

 

[m.schuey7]

After some trail and error I came up with this with stock primary weights: Added the MPI BIG steel rivits (which you cant buy from them anymore but you may be able to find out the weight from them) on the inner two holes and and the heaviest Yamaha alum rivit on the outside hole. this worked perfect with stock secondary. would just touch 9000rpm in powder / 87-8800 in grippier snow.

 

[TPAY243]

M.schuey7 that's what I'm running into i can't find a heavy enough rivets. I have the biggest ones Yamaha makes in all of the holes in the weights and this thing is hard on the rev limiter(9300). There use to be a couple of different vendors years ago that sold lead rivets but I can find any anywhere now. Might try some Apex or Winder weights. Thanks for the input much appreciated.

 

[Srxspec]

Stm 60 gram weights, I can set you up with the weights if you don't have some already.

 

[TPAY243]

Thanks Allen I'll try and get a hold of you on Wednesday.

 

[Srxspec]

Thanks Allen I'll try and get a hold of you on Wednesday.

I looked through my notes, I used a different primary spring & the 60Y STM weights, stock secondary. Give me a call Wednesday and I can get you setup.

 

[TPAY243]

Would like to give a shout out to Allen from Ullmer Racing I called and talk to him with the problems i was having with the clutching on the supercharged Nytro. He sent me a set of stm weights and spring, I installed them to day and tested it everything was spot on, runs 8750 rpms and pulls way harder than it did with the stock weights. Thanks Allen again great guy to work with.