VintageVmax.com

Hey guys, I just got a new 108C for my 81 srx and would like suggestion on spring and weights to use for a good performance on the trail. Thanks. Richard.

Thanks anyway I found the answer on the Comet site

I found the setup on the comet site was engaging too soon and needed about .040 inch of shim on the spring to work right.

The instructions on the site say to start with their settings, but my kit had three 0.020 spacers in the kit to adjust engagement to my taste. I used two of the three spacers. Each spacer is good for about 200 RPM increase in engagement RPM.

yeah we have found that the recommended spring from comet comes in too early on the vmax, i wouldnt be suprised if that held true with the srx.... unfortunatly i dont know what to recommend... something tells me you want the srx to engage at 4900, but dont take my word for it on that

Tyler Do you think the N-1 ramps with a purple spring will do the work ?
I am using a 108exp clutch

mmmmmm not sure.... at one time my 81 had a 108 on it with a square yellow spring... i believe it was coming in at the right rpm but unfortunatly i never got that motor to run right.... the clutch was a 108-c not the exp and i dont know what the weights were... i am by no means an expert in this area im just telling you what little i do know.... honestly im not completely sure what clutch belongs on the 81srx... if it is a 102 you should use a 102, if you have one.... from what ive seen and read those 108's just make things even more difficult (not impossible but not sure fire either)....

the main problem with using the 108 is that it is a overdrive clutch which requires a overdrive secondary to maximize its potential.... things can be modified here and there but you kinda need a bunch of parts to swap in and out.... its kinda like a "hmmm wonder what this will do?" thing....

one person who would most likely be able to help more than me is YAMMIEGOD3:16 (tony) over at http://www.totallyamaha.com ... he comes in here on occasion, and i figured maybe he would jump in on this and set you straight but i havent seen him yet...

chuck(vmax540) is running a 108exp on his 86 vmax but he also had the secondary milled down so that it will open wider and allow the belt to get higher in the primary and lower in the secondary, thus actually utilizing the overdrive ratio.... (pain in the butt if you ask me) he has the purple spring and one or two washers, with (i assume) A3 weights and it comes in at like 4400 or so... which is good for the vmax but the srx is a different animal (more like a demon)

like i said im not an expert on this clutching stuff but ask me questions and ill throw my two cents in

sorry i dont mean to make this seem like rocket science..... its not, its just nicer if you dont have to mess around ordering different parts and wasting money... if you put the purple spring on, with the N-1 weights its will go.... how good? im not sure.... i posted over at totallyamaha.com.... hopefully some one jumps in with some experience in this

Rick, Try doing a search in the Garage, lots of good reading from opsled, agfirecat and others on Clutching !

Let me recall about utilizing a 108 EXP on my '78 srx oval sled. The simplest way I could think of to have to secondary open further in order to compliment the higher gear ratio of the larger circumference EXP was to chuck the helix of your chosen angle (45,47 or 49?) into a lathe. With the helix spinning in the chuck, I cut the circlip groove, only the groove, deeper into the helix casting. This would allow the driven to open further. I remember seeing that at idle the plastic pucks installed in the fixed half of the driven barely sat onto the edge of the ramps of the helix, but that was not a problem because you immediately shifted right out of it. Of course there is the question of the difference between the sheave angle of the faces of the factory driven vs. the angles of the EXP and its accompanying belt. These were not the same. I thought this was important as I wanted the maximum grip for hole shots, corners,whatever. I went to a shop and asked them to recut the angles on the faces on the driven, so that it would match up to the angles of the new driver. We got pretty close until I said "stop! we are getting thin, enough metal taken off". The transmission ended up shifting out fully, and the secondary never got weak and blew up. Thats my story and I am sticking to it. See you later guys. MJD.