Primary clutch modification

[racerone3]

I was needing a 1 1/8 clutch for my coot project, and after a few too many beers decided to modify a one-inch clutch I had laying around. (Comet 780) While studying on the project i saw a few things that make me think it started life as a 2 stroke clutch.

Anyway... Chucked it in the lathe and bored the ID out to the size I needed, then broached a new key way. Now that it is installed and in use, I am quite sure that it was a two stroke. My plan is to add some weight to the clutch arms, to lower its engagement speed. Does anyone on here have any experience doing this sort of thing. Any advice or warnings would be appreciated

[Surfer Dude]

Maybe i'm wrong but if it was a 2 stroke clutch wouldn't it of been a tapered shaft clutch? In any case. here is the website I found a while back on clutch weights and engagements rates. If you have never done one of these clutches they are super easy. remove the top 3 bolts by bending the tab out of the way and simply unscrewing the bolts. there is no constant spring pressure on a 780 so no need to worry about the top flying off or anything. once you pull them top three bolts out just remove that bell and inspect for any "deep" grooves where the weights ride. you need to figure out what weights antd spring you currently have. The max factory used Blue weights/blue side cones and purple springs from 1998 and up. which according to the site i've linked would be an engagement of 1,850 rpms. let me know if you need anymore info than that. Don't know how much you were looking for.

http://forums.bajasae.net/forum/uplo...SAECatalog.pdf

[Joe H]

Hey Race, I gave hydromike some weights for a salsbury a while back that I believe are for a four stroke maybe there is a part # on them. If not try searching for old golf cart parts, I am thinking Yamaha used a salsbury for a while.

[hydromike]

That's the first thing I thought of Joe. I offered him up the weights, but Race is a staunch DIY guy and is only going to take charity if he fails miserably at every other option. Birds of a feather, ay?

[racerone3]

Maybe i'm wrong but if it was a 2 stroke clutch wouldn't it of been a tapered shaft clutch? In any case. here is the website I found a while back on clutch weights and engagements rates. If you have never done one of these clutches they are super easy. remove the top 3 bolts by bending the tab out of the way and simply unscrewing the bolts. there is no constant spring pressure on a 780 so no need to worry about the top flying off or anything. once you pull them top three bolts out just remove that bell and inspect for any "deep" grooves where the weights ride. you need to figure out what weights antd spring you currently have. The max factory used Blue weights/blue side cones and purple springs from 1998 and up. which according to the site i've linked would be an engagement of 1,850 rpms. let me know if you need anymore info than that. Don't know how much you were looking for.

http://forums.bajasae.net/forum/uplo...SAECatalog.pdf

Signs that it had been a tapered shaft were what had me thinking 2 stroke. Thanks for the link. It at least gives me some idea where to start

Hey Race, I gave hydromike some weights for a salsbury a while back that I believe are for a four stroke maybe there is a part # on them. If not try searching for old golf cart parts, I am thinking Yamaha used a salsbury for a while.

Mike already offered me a set. And as he mentioned... I gotta try it myself first.

That's the first thing I thought of Joe. I offered him up the weights, but Race is a staunch DIY guy and is only going to take charity if he fails miserably at every other option. Birds of a feather, ay?

Pretty well sums it up.



Today I made my own set of rollers. More than three times the weight of the ones that were in it, and saw absolutely no change in Performance. Hydromike is sending me a set of true 4-stroke parts to try. I truly believe that adding that much weight should have made some difference. It may be time for me to get educated about speed-sensitive secondary clutches. Perhaps the problem lies there

[Joe H]

I understand the wanting to do it himself perfectly !! There is a whole array of springs for the salsbury and the shape of the dust cover also affects shift... just a little food for thought.

[ARGOJIM]

Brian, are the face angles the same as one of your 4 strokes?

[racerone3]

Brian, are the face angles the same as one of your 4 strokes?

Not a clue! I've had great luck for years just winging it on clutches, and therefore never been forced to learn about them. The Wild wolf is still running the secondary that came on it from the factory with the2 stroke spring. I will look at the face angles on a few other machines and report back.

[ARGOJIM]

Never mind that , watching the tv and typing, Joe is onto something. What I think also was seen is that the driven, in one picture looked to have been a 7/8" or 1" belt similar to the early Attex machines, did you widen it with spacers changing the spring rate? Belt alignment looks off in the pic, but may just be pic.

[racerone3]

Belt alignment is off. I need to space the clutch out from the trany a bit. The belt is 1 3/16 wide, and I didn't change anything on the clutches to accept it. Lubed up both clutches with dry graphite last night, then found that the belt is chunked, so I didn't try it. New belt ordered