Yamaha Coupler weights and dimensions

[OCD Solutions]

Messing around in the garage with parts today and as I'm now in the habit of weighing everything figured I'd post up some of the results for reference material.

1) OEM roundnose coupler set 1.74 lb
2) GP800 66E Coupler set 1.81 lb
3) Billet Superjet Set, make unknown 1.35 lb
4) side by side comparison of all 3
5) Stock SJ beside lightweight SJ

Not as much weight difference as one might expect but the difference in rotating mass due to diameter alone is quite significant.

 

[Berky]

Man I forgot to weigh my Danger boy coupler before the install.

 

[OCD Solutions]

Man I forgot to weigh my Danger boy coupler before the install.

I was talking to Chris about his, that's what actually prompted me to do this.

I just picked up a Pelouze 4040 scale for my Matrix build too. After seeing all Josh's pics and weights during his build I figured I'd get with the program.

My little scale will do up to 75lbs and this one is good to 400.

 

[OCD Solutions]

From the horses mouth...

Yamaha 701 / 760 Lightweight Drive coupler

Cold Fusion has Created what we believe to be the strongest, lightest couplers on the market today
A typical Yamaha coupler set with dampener weighed in at 1.878 lbs ( kawi style at 1.58 lbs)
the Cold-Fusion set weighes in at 1.275 Lbs, a savings of well over half a pound of rotating mass. Even more advantages is that this mass has been removed from the outer diameter

 

[Waternut]

Yeah I was getting ready to post "from the horses mouth" but then I realized you weighed your couplers with the dampers and Dangerboy didn't specify whether his weights were with or without couplers and the weights are close for stock but not the same.

I guess any way you look at it though, the smaller kawi style couplers have to be better since all the weight is closer to the center.

 

[OCD Solutions]

Yeah I was getting ready to post "from the horses mouth" but then I realized you weighed your couplers with the dampers and Dangerboy didn't specify whether his weights were with or without couplers and the weights are close for stock but not the same.

I guess any way you look at it though, the smaller kawi style couplers have to be better since all the weight is closer to the center.

I just wrote the difference off as a scale difference but you could be right about the dampers. If anyone would like to send me one I'd be happy to weigh it and add it to the post. :biggrin:

 

[Waternut]

I don't have a nice scale and kept meaning to take the couplers to the post office when I went but I always seemed to forget and eventually just said screw it and installed them.

 

[OCD Solutions]

I'm getting in the habit of weighing everything and it's easy right now with my ski torn down to pieces. My little scale was $18 shipped and I snagged the Pelouze for $70 shipped.

I'm planning to add the weight of each component to my build cost sheet for future reference. Can you tell I'm bored waiting for my hull to arrive?

 

[Waternut]

I did the same thing with my 750. I started with the SJ and once things started souring up to the 300lb mark with other parts to go, I stopped.

 

[Waternut]

Well I took one for the team. I removed my cold fusion couplers since it hadn't been torqued down from riding yet. With my modified 750 coupler, it weighed 1.28 lbs. Without the damper, they weigh 1.11 lbs.

For comparison between our two scales, my stock SJ couplers weighed 1.71 lbs but they have lost some material and most of the paint from rubbing the coupler cover and bilge pump. I'm calling the slight difference between our two weights on stock couplers due to that.