Clutch Question(s) RD350

[suey1958]

I have a 73 rd350 project . Prior posts indicate that some earlier clutch assemblies are different,... Just want to figure out exactly what I have here.
Case numbers are 351-112436  . I think that means that I need 7 plates and 7 fibers ?

Also, I have 2 different types of plates and was wondering what the differences are.

[Jspooner]

If you have a 73 you most likely have a 6 plate clutch unless someone already upgraded it to a 7 plate. The plate on the left in your pic is an RD400 steel.

[suey1958]

Thanks J Spooner. The bike was a mess when I got it and many things had been changed (Not upgrades though) Is there any way to measure anything there just to be sure?

Metal plates always go in first, Right?   Thanks Again

[SUPERTUNE]

Yes, post pics of the inner hub. If its a 6 plate clutch it will use a spider inner hub.
7 plate clutches use 6 metal plates and 7 fiber plates.
6 plate clutch has 6 metal plates and 6 fiber plates with one steel plate being thicker and is used as the first plate to go in as its the back plate.
Stock mid year '74 and later use a aluminum back plate and don't use a thick steel plate.
Chuck

[suey1958]

Thanks Chuck, I will post pics later today.   

[suey1958]

This one had 6 metal and 7 fiber plates in it when I took it apart,....I didn't think that was correct,...I though you always start with a metal plate.    ?

[Jspooner]

That style of hub and pressure plate should only have 6 of each plate.

[suey1958]

OK, Got it. All my steels are the same thickness,...Any idea where I can find the thicker plate (that goes in first) that Chuck referred to in a previous post?
All the ones I am seeing for sale look like the same and make no mention of thickness. Thanks

[Jspooner]

OK, Got it. All my steels are the same thickness,...Any idea where I can find the thicker plate (that goes in first) that Chuck referred to in a previous post?
All the ones I am seeing for sale look like the same and make no mention of thickness. Thanks

I have some.

[Jspooner]

So it should have one thick steel 5 thinner steels, and 6 fibers.

[suey1958]

Thanks JSpooner for the clarification on that. I will be sending you a PM,... First going to try and determine if I am missing any other parts before I message you.

[EE]

From here it looks like hes got an early cover with a later inner hub. Either way if Joe has the parts upgrade to the later 7 plate clutch, Yamaha changed the design to eliminate slippage issues. You just use the later inner hub, later cover (it will have "teeth" that engage the inner hub), and 6 thin steel plates.

[suey1958]

Does this look like the cover that I should be using?  The previous owner had some things all mixed up,...Truth is that I dont know much more than he did. LOL

[Greaser Greg]

I really appreciate all this info, as the decaf project I'm working on came with seven steels and washers on the screws. Didn't the washers get added in '72? Thought they caused the scraping in the case, but now I think it was the extra plate, since the cover wasn't centered over the six screws when I pulled the cover. Do the '71 R5Bs get washers on pressure plate screws, or not? The manual's I have say no, according to the pics.

[SUPERTUNE]

Does this look like the cover that I should be using?  The previous owner had some things all mixed up,...Truth is that I dont know much more than he did. LOL

Yes, that is the right top pressure plate. Use that with the inner hub you have installed.
The inner hub is right for a 7 fiber plates and 6 normal steels. This is known as the 7 plate '74 mid later and all 75 RD350's.
A thick plate is only used on the inner spider hub with 5 normal plates and 6 fibers and 1 thick is the first one in as a back plate.
These are all known as early '74, 73 RD's, R5's and DS7's 6 plate clutch.
We call them by 6 or 7 is how many fibers each clutch have.