VintageVmax.com

Will the p-85 clutches work on an 1985 vmax?

For clutches to work right and belts to live depends on two things, the center to center distance and the offset between the two clutches.
Most clutches use a 30 mm taper, thats common. Where this gets weird is the depth measurement of where the taper starts.If you look at a Comet catalog you find many clutches listed, The tunning parts are interchangeable, but the differance is where that taper starts inside the bore of the clutch There are many clutches that are identical EXCEPT for this off set. This offset is what keeps your clutches aligned to each other, and this is inportand AT THE FACTORY SPEC.

Were talking a relatively small differance between these different offsets so here is what I do.
My V Max has the factory clutch on it. If I had the engine loose, I use the factory spec to line it up again , which is right where it came from the factory. Now, My SRV has a different offset clutch on it, I still tighn it up to the factory number, but because the offset depth is different my engine is slightly offset from where it originally came with. In other words I slide the engine over exactly the amount of the differance between the factory clutch and the new one you are using. The engine moves so the offset between the two clutchs remains where its supose to be.

At that point you can use the same tunning arms and springs in either the P85 and the Comet 102-108. Again in other words, you can put Comet parts in a Pol. clutch or vise versa

I had the p-85 on my old vmax but it had the polaris secondary as well...

where did you find the shaft to run the secondary polaris clutch? were they off an xlt? i see alot have converted to either the xlt or xcr setup. thanks to all for the feed back.. snows comin!

I sold it to my buddy i dont know, we could take some pics i guess...I think its just a polaris jackshaft couldnt tell ya i got it out of michigan it had the polaris clutches, heat temp gauges , studded track, carbides and the guy i bought it from said
it was just a trail sled lol ya right.

Hey Bob,
I read your reply about the clutching so your saying that an srv primary will work on the vmax but you just have to move the motor over? If this is true do you know how far you have to move it? I just got an 87 srv clutch to put in my 83 vmax I am hopping it will work please let me know thanks.

Two seperate issues. First, is it a Yamaha version of the comet, or is it the basic Yamaha clutch, sorry don't know the name, thought it was YPZ or something. If its a comet style then you can just use the Arms and spring they recoment for the VM. If its the Yamaha style, I don't know if they ever came on the VM so I don't know whats available for a set up. The SRV set up will not be right.

Now for alignment, measure the differance between the offset on the two clutches you have and which is closer to the edge of the shaft. That is how far you have to move the engine. What you want is this clutch to sit exactly where the factory one was. If you have to move it much, check for clearance on everything so nothing rubs or hangs up