1982 YZ80J clutch

[bruce g]

Hi Guys
Am a bit of a four stroke man only ever owned 2 , two bangers in my life a YZ80C and a Hodaka 80 which was a 10 inch wheel version of the 100 dirt squirt bike originally with lights
I acquired 2 near complete yz80Js for nicks my mate was going to throw them out
decided to do a resto on both so sell one and keep one
my problem is the clutch basket in the engine i have stripped is badly worn would love to put a billet basket on this engine, as im working this engine with a good port job and head chamber work that Dave 2 stroke performance is helping me with going to be a DG themed red and white one
even modified the intake ever so slightly to take a G Force reed
and milled up the head to look like a billet anodised VHM
have been doing some research on baskets and 1982 models don't seem to have a billet one available,but can get a 1986 billet one
I can only check out pictures of both standard baskets for 1982 and 1986 and they seem very similar
anybody on this forum got a bit of knowledge to know if they are interchangeable
I know some of the bigger Yamaha models are
am going to do a thread on the resto have already got some trick parts for it
thanks for any help in advance

[rocketfrog]

I cannot say whether it will fit or not but I am keen to see how this thread pans out. I would bet that the 86 clutch would be very similar.

Check out the parts diagrams for interchangeability of the components: for example if the J uses same Axle,main as the the S

( refer to http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1982/YZ80J/TRANSMISSION/parts.html )

Then it is a safe bet that the clutch assy will fit up to the shaft, take note of the following:

The primary gear from the c/shaft is helical (5X2-16111-00-00) on the J and straight cut for the S so this might be a show stopper unless you can splice the basket from the S onto your primary gear. Looks like a new clutch introduced for 1986?

The gasket for the clutch cover on the YZ80J is the same for YZ80S which leads me to believe the cover is SIMILAR, I am only speculating because there are holes in the parts diagrams where Yamaha have duplcated the H and J diagrams.

You need to find someone with an S that can verify a few details to be sure. If you post a wanted ad on this forum for a shagged clutch from a YZ80S you might get lucky that someone will send you a donor for the cost of the post. At least you can see what needs to be done and if it is viable before shelling out for a billet unit.

Best of luck, I hope you find a way to do the swap. 

[Viper666]

Here's a list of what uses the same clutch plate so it stands to reason the basket is going to be the same or similar.

http://www.boats.net/parts/detail/yamaha/Y-21V-16321-00-00.html

One listed is 1986 MOTOCROSS - YZ80S CLUTCH

[rocketfrog]

Remember that the plates are only part of the fitting aspect. I would suggest looking at the rivet layout on the primary driven gear between the two models as I believe this will dictate just how straight forward the swap will be.

Most aftermarket billet clutch baskets that I have seen are sold as a replacement which utilises your existing primary driven gear. That is to say, in order to fit the billet clutch, you must drill off the old basket and retro fit the gear with the new basket and rivets supplied with the (Talon, Mitaka, Wiseco etc) kit that you end up buying.

The primary gear must match with the drive gear off the crank end, and the also the kick start idler gear if you are going anywhere without custom machined components.

If the billet basket can be made to match the primary driven gear without too much fuss, your cooking with gas

[crossedup2]

A quick look at the different models shows the number of friction plates goes from 5 in 83 model to 7 in the 04 model. That would mean the basket would be deeper which might end up with a side cover clearance issue. The yamaha parts pictures show a different number of retaining rivets at the back of the primary gear 3 (83) to 6 (2004). That should not be a real problem.

Others have had similar issues and seem to have resolved with some luck.

http://www.thumpertalk.com/topic/852067-yz80-clutch-basket-cushions/

So with a bit of fiddling and some luck the new basket could be made to fit.

Peter B

[bruce g]

thanks very much fellas for the input great help
going to bite the bullet and buy a billet basket
as they say have lathe have mill can speak English so should be able to make it fit
been slowly getting all the other bits together
i will do a progress thread{think that's what you call it}
on the progress
thanks again the forum is a great wealth of people and knowledge
cheers

[bruce g]

http://s300.photobucket.com/user/logistics835/media/prox%20basket_zps5ey7pvgt.jpg.html?sort=3&o=0

Hi Fellas
Got the Prox basket and did a little bit more research
highlight the above link,right click and hit go to for a look at the pics
so the way it goes is prox only makes a basket as early as a 1986 yz80
this is the basket i brought after looking at it and working out it should be similar
the 1986 model runs the same clutch plates and discs as the earlier models but the difference is it has 6 plates
where the 1982 J has only 5
so got off evilbay a 1986 inner and outer pressure plates for 25.00
then have ordered 6x barnet plates and i have enough spare good discs
the next dilemma was clearance inside the cover, dummy assembled the basket and covers and used a fibre optic camera to have a squisz
these cameras are a invaluable tool when modifying engines to check clearances where you cant possibly see
looked all good but i have put a small chamfer on the outer edge of the basket just to make sure,that's the polished edge you see in the pics
clutch rubbers didnt need replacing they where all good
thanks again for all the people that helped 'cheers
Bruce