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The Clutch Decision
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We spend a lot of time in our shop making large output V-Max engines for people all across the country. Many of these bikes are shaft drivers as well as chain bikes. The one thing everyone seems to have in common is the propensity for huge, super sticky meatballs for the drive wheel. The rear tire compound recipes available today are awesome especially in the seventeen inchers. You have to know by now that your V-Max just has to have wider, lighter wheels large enough to hook up all that V-4 torque!
"I want the bigggggest, badddddest tire I can get. I'll saw the swing arm up if I have to but get me that tire NOW!!!' This is only part of the conversations we have on a weekly basis. There is one thing those crafty Japanese engineers found with Max that is very important. They set that bike up to spin the tire. Most of us agree that tire spin is an annoying way to lose that race against your neighbors "hot rod" GSXR when actually it is a carefully calculated relief valve for Max. Clutch and associated drive line reliability are dependent on that tire spin. Don't lose faith big tire worshippers! Help is on the way. After years of burning clutch plates and trying all the different remedies we finally found a practical solution. No, it's not a coil spring conversion even though that is the popular belief. Coil spring conversions require a tremendous amount of additional spring pressure to function at all. This translates directly into a ion of handlebar lever pull resistance yielding less clutch clamping pressure than a new stock diaphragm spring!
Hold on, I'll explain this so don't start screaming at me yet. It's time to bring back those crafty engineers who designed all this stuff and who I've learned to respect very much. They wanted a clutch that was simple, light weight and most of all smooth. Yamaha started out with the Venture in the early eighties and it had a coil spring clutch. After the VMax came on the scene and they realized how well the diaphragm worked they changed the Venture's clutch to that design. Two up with a trailer, up the mountain side in third gear, 5500 rpm no slip. Period, the end.
The entire V-Max clutch is set up around the big, smooth reacting diaphragm spring. The clamping pressure of the big spring is delivered directly over the clutch pack on it's outer most perimeter. A coil spring conversion delivers it's pressure on the much smaller bolt circle which was the center of the old diaphragm spring. This type of geometry requires the pressure plate to transfer the clamping pressure to the outer edge of the clutch pack where it is needed. Well, guess what boys! Max’s pressure plate flexes like crazy. You take the valve springs out of your car and put them in there and it will still slip.
Don't give up on Max's clutch because there is a solution. Go to your local Yamaha dealer or call our order desk and ask for a V-Max diaphragm spring like the one you already have in your bike. We call it the Double D clutch mod in our catalog. Simply unscrew the six hex headed bolts that hold your existing spring in place and add the new spring right over top of the old one. Put the six bolts back in the center, hang the cover back on and off you go. You will notice a slight increase in handle pressure but you will be rewarded with ridable, workable clutch. This double spring unit has held more than 220 rear wheel H.P. on our dyno and can break: your crank in half in fourth gear if you use a little too much NOS!!!
There is another small trick that helps extend clutch life. This is the removal of the "shock absorber" which is installed at the bottom of your clutch pack. Through the use of another small wave washer, Yamaha figured they could tame that low end punch and soften aggressive clutch engagement by springing the platform that your plates sit on. It sounds great in the brochure, but it's just too bad that it absorbs a lot of your clutch spring's valuable clamping pressure. Simply remove the retaining wire, full sized steel plate, small friction disc, wave washer and steel shim. Replace that metal trampoline with a single standard, full sized friction disc Yamaha part #26H-16307 -00. Put the full sized steel plate over the new disc and re-assemble the rest of the clutch.
Call or write our shop (info in PCW Racing ad) and we can send you a service flyer with step by step instructions on the clutch mods. Oh and by the way, the old retaining wire is a great way to hang the 8 by 10 glossy of you and Max posing proudly and of course, fully assembled!

By John Ganey
VBOOST Voume1, Issue 2, 1997


Posted on: 2013/10/18 13:43
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Be safe out there and enjoy the ride....

Mike Moore
VMOA Webmaster


Re: The Clutch Decision
Not too shy to talk
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I have the Barnett Clutch Spring Conversion Kit (it comes with 75 lb. Gold Springs) and love it.
Barnett Part # 511-90-10002.

It does increase the lever pull by about 20% but it's no where near as bad as with the DD mod.
And you can always upgrade to Green Springs (or 3 Green and 3 Gold) for even more grab.
501-82-06023 (MT-23-6) = green 82 lb at 1-inch

Posted on: 2013/10/25 17:57


Re: The Clutch Decision
Webmaster
Joined:
2001/8/20 12:00
From Mount Airy
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Posts: 459
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I personally run the DoubleD mod and I use adjustable levers which make it just as easy to to pull the clutch in to shift as stock. I love this setup and I have been running it for years.

For more information and purchasing adjustable levers, contact captainkyle-3558 on here for a great deal. His contact number is: 813-270-0000.

Posted on: 2013/10/26 11:29
_________________
Be safe out there and enjoy the ride....

Mike Moore
VMOA Webmaster






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