nitromator
Newbie
I have an 09 Nitro MTX 153. Was having some problems in deep heavy snow last year, where I lost RPM while climbing. I think the secondary clutch was not backshifting fast enough or at all. Has anyone installed a roller secondary? Did that improve backshifting or would increasing spring tension on the stock clutch do the same thing? I see that MPI has a roller clutch available that works with the stock helix or you can also install a multi-angle helix. What helix angles would work best for 5,000 - 7,500 ft elevation.
HYFLYR
TY 4 Stroke Guru
You already have a 39 degree helix, that's a fast back shifting helix as is. I would try increasing spring load on the secondary first before switching to a whole new clutch. Don't be afraid to jump in there and make changes and see what works for you. It should be set at 3-3 in your secondary stock, try going to 2-6 or 3-6 and see if it helps. Its a simple fix and only takes a minutes even on the snow. Good luck and have fun.
Oh and make sure you have the yamaha black spring with white stripe.
Oh and make sure you have the yamaha black spring with white stripe.
clatla
Pro
I bought a clutch set-up from Scott at OFT Racing last year. It is spot on at Sea level and at 10,000'. Of course 2 different set ups. It was a primary spring, arms and a secondary spring maybe rollers too. All Yami parts. I tell you it was night and day difference from the stuff I had the year before.
nitromator
Newbie
hi, thanks for the information. I'm pretty sure my problem is with the spring tension in the secondary clutch. I have the stock 'pink' spring installed. Will install the 'white' spring and increase the preload, hopefully that will improve the backshift. Now all I need is snow for testing.
