Primary weight options for a tune

[Motorhead]

I will likely change the primary spring too as I'd like to keep the engagement around the stock level and I see good things about the XS825 belt so I may just try that next winter too.The guy here in NB that is the TD rep told me the 270 Power Trail tune is what would work best for me.I don't need to push the limits,I'm really only looking to add the tune so I can run the muffler mod and get better fuel mileage out of the sled.I told him I didn't want to get into changing the BOV or have to monitor t

That Power trail tune with a performance muffler is one of their first tunes. My dealer/TD rep sold those back in 2017/2018 winter. The stock clutch set up with the added 1.5 grams to the tip, the 35/39 helix and the machining secondary to avoid coil bind, was his set up!

Now I see that TD offers both the Eco and Power trail in a stock muffler tunes! Just a lot of tunes to choose from huh?

So yes, nice plan but beware of the Boost addiction, it’s real!! Ha Ha...

 

[justinator]

Stock primary spring works well if you add about 1.5 gram to tip! That’s done by drilling out your stock weights, and then adding new 4.5gram rivets with an added 1.5 gram washer while installing all! That combination worked best for me with a 35/39 helix. The helix helps with WOT over rev! Secondary setting at 6/1 is my fav!

Problem with stock primary spring, they break after 4-5K miles, so this year I also tried an old set up from my MS16 2 bar days.The Yamaha Blue Brown Blue with stock weights and no extra added to tip. That set up likes the stock helix for the added revs, it didn’t like pulling the 35/39, again belts are a big difference with WOT revs!

Note: not all primary weights are the same on all years of the winder! My 17 came with the 8LR ramps and heaviest rivets (17.2mm) or 4.5 gram on all three holes!

Some come with 8KC Ramps and last River is a very light aluminum!

With that said, you see why many go the way of Daltons or other easy to adjust ramp/weights…

Not sure about mtx models of sidewinders but all other models on all years use the 8lr weight. 19 and later have .85 gram in tip and 35/39 helix instead of 4.5gram tip and straight 35 like 17-18.

 

[earthling]

Not sure about mtx models of sidewinders but all other models on all years use the 8lr weight. 19 and later have .85 gram in tip and 35/39 helix instead of 4.5gram tip and straight 35 like 17-18.

Including the 21/22 SRX?

 

[Motorhead]

Not sure about mtx models of sidewinders but all other models on all years use the 8lr weight. 19 and later have .85 gram in tip and 35/39 helix instead of 4.5gram tip and straight 35 like 17-18.

Good info to know if you are planning on playing with stock clutch ramps/rivets..

I bought a new used set this season, they came off a 2021 or 2022. They looked brand new and that’s when I noticed the much lighter tip weight on the same 8LR ramps as my 17.

Very tough year getting Yamaha parts this season, so in working with a friend rebuilding a set of 17 weights to make a full set, the ones that the dealer tried to give him were the other ramps. We said wrong ones, So he took them back to his stock room and returned with the 1 proper ramp that we needed!

So just an FYI to those playing with stock weights! There are differences with winder weights of different years! You have a better understanding of what and where then some, including me.. Ha Ha!!

 

[justinator]

Including the 21/22 SRX?

Yes should be 35/39 with pink spring at 3-3 and 8LR weights with light .85 gram aluminum rivet in tip, gold-red-gold primary spring. Same clutching as other models 19 and up.