Stock primary weights indentations?

[Motorhead]

Doing a quick check on sled prior to a last upcountry (county) trip, and found some wear on my primary weights!

Weird thing for me is, these were new end of last season, and I’ve never seen any of my past Yamaha weights do this.

Last season, I replaced both roller and ramp/weight, I think at about 8k, and instead of utilizing stock rollers 14.8mm, I tried the Gforce 15mm rollers. Checked rollers half way through season and one of the bushings was showing egg shape wear starting, so I put another set of the same 15mm Gforce back in, and at that time, weights looked perfect! So not to ruin last trip, I simply put my Dalton QA 70’s in!

Have never seen any wear like this on any of my many Yamaha sleds primary weights, so wondering if the 15 size may cause this?

First dimple on heel is at engagement spot.
Dimple 3/4 ways up is at about 3/4 clutch not full shift out! So probably my cruising spot 80 - 105.

 

[Stubbs]

The three holers are hard on weights, period. This started with the original 973cc Three cylinder Vector/Venture motor and has been a thing ever since. If you spend a lot of time cruising at one speed this is just something you’re going to have to deal with. Roller size doesn’t seem to have an effect on this wear. In my experience the stock weights actually resist grooving better than any of the aftermarket weights I’ve tried.

 

[Trailleader]

Is that a hardening issue?

 

[Motorhead]

The three holers are hard on weights, period. This started with the original 973cc Three cylinder Vector/Venture motor and has been a thing ever since. If you spend a lot of time cruising at one speed this is just something you’re going to have to deal with. Roller size doesn’t seem to have an effect on this wear. In my experience the stock weights actually resist grooving better than any of the aftermarket weights I’ve tried.

Yes on this 3 cylinder motor being hard on primary clutch components, but very strange that the only reason my original weights got damaged, was from roller bushings wearing out, and causing damage on one of the weights because of how it no longer rode flat on the roller, and only used a portion of it causing that one weight to have a wear spot the entire length of the weight! The other 2 are still in use on my friends sled whereas he needed some last season, and I had a couple! This new set with the added 15mm rollers only lasted maybe 2K! Wow, really got to keep an eye on these, they start wearing fast and if you don’t catch them, they will come apart!

Maybe time for an Apex type clutch!

 

[Stubbs]

Yes on this 3 cylinder motor being hard on primary clutch components, but very strange that the only reason my original weights got damaged, was from roller bushings wearing out, and causing damage on one of the weights because of how it no longer rode flat on the roller, and only used a portion of it causing that one weight to have a wear spot the entire length of the weight! The other 2 are still in use on my friends sled whereas he needed some last season, and I had a couple! This new set with the added 15mm rollers only lasted maybe 2K! Wow, really got to keep an eye on these, they start wearing fast and if you don’t catch them, they will come apart!

Maybe time for an Apex type clutch!

Vectors have the exact same clutch as an Apex and will also groove weights and eat roller bushings if you spend extended periods of time at a constant RPM and don’t keep an eye on them. It’s the harmonics of the three banger, no getting away from it. I do agree that the previous gen Yammy clutch is much more reliable than that new POS they’ve bolted to the ‘Winder though.

 

[Stubbs]

Is that a hardening issue?

Not 100% sure, but some wear faster than others. Likely a combo of hardness and contact area between the cam arm and the roller. In my experience narrower weights with less roller contact seem to wear faster than arms that are wider and have more contact.

 

[Motorhead]

Is that a hardening issue?

If a slightly higher profile roller isn't the issue, my bet is what you have stated. Hardening issue with some?

 

[Motorhead]

Not 100% sure, but some wear faster than others. Likely a combo of hardness and contact area between the cam arm and the roller. In my experience narrower weights with less roller contact seem to wear faster than arms that are wider and have more contact.

I can surely say that some wear faster then others, whereas two of my original weights that had 8K on them, were needed for a friends sled at the end of last season, so he bought one new, and bought new bushings for my old two weights. They are still in use and looking great!
My newer model weights, not so good!

 

[Motorhead]

Vectors have the exact same clutch as an Apex and will also groove weights and eat roller bushings if you spend extended periods of time at a constant RPM and don’t keep an eye on them. It’s the harmonics of the three banger, no getting away from it. I do agree that the previous gen Yammy clutch is much more reliable than that new POS they’ve bolted to the ‘Winder though.

Yes compared to the older style Apex/Vector/Nytro clutch, this sidewinder clutch is a POS. It reminds me of the clutch that they put on the 2000 phaser, that one also had no set screws for the roller pins, but had no other issues because it was an underpowered twin?

 

[Stubbs]

Twins can be just as bad, if not worse depending on the design of the crank. Old school VMax 540’s were really hard on clutches, but the Exciter 570 motor wasn’t nearly as bad. The late 90’s VMax 500’s were a little hard on roller and weight bushings as well, with the 600 motor being better. All of those issues vanished with the introduction of the 600/700 red head triples.
Back in the day I piled a ton of miles on an improved stock Phazer with both YPZ and YXRC primary clutches and don’t remember either set up being that hard on clutch parts.

Holy post de-rail! Sorry about getting so off topic.

 

[1nc 2000]

I have had stock and stm weights wear like the pics above.
I have been running thunder products clutching weights and no wear issues.
This is in a Nytro primary on a sidewinder.

 

[Stubbs]

I’ve seen STM Supertips groove in a 4 stroke triple with lots of miles on them, and had Dalton QAY’s of my own start to groove in just a season and a half on a Nytro. My father just put some Thunder HH in his Vec and all he really does anymore is tour with it so we’ll see how they hold up.