Do R5/RD cases have to be used as a set?

[Greaser Greg]

I have a decent top half, will it work with any good bottom half? Do the cases get matched at the factory when produced?

[Barrie]

Yes , it is normal for them to be machined as a pair,
but I know people who have changed just one and have got away with it without any major consequences.

[Greaser Greg]

 ;D

[m in sc]

ive done it a number of times. its fine.  hell, one time i was desperate and used an r5 lower case with an rd upper one. 

[teazer]

Hm.  That's odd.  I have a set like that here.  RD top half and R5 or DS7 bottom half.

[Diablo007]

Interesting.  I have heard that they are machined as a set so should not be mismatched.  I've also heard that the manufacturing tolerances were good enough that it "shouldn't" matter.  I have a factory replacement case with no VIN stamped into it.  Somehow the bottom half had a big hole punched in it.  I've been debating for years whether I should toss it, sell it, or just swap the bottom half with another motor and stamp the top to match one of my bikes.

Guess I'll hang onto the cases and follow this thread.  Unless someone wants to make an offer on them... ;)

[m in sc]

This conversation has come up before. Ive -never- seen a mark that links numerically the top to the bottom end from the factory, ever.
teazer, that's not my old motor, i know where that one is. 

[Greaser Greg]

Like this?

[m in sc]

like that. ive never seen that on a set of cases i have, as far as i am aware.  I can double check sets i have tonight, ive been wrong before. 

[m in sc]

just checked 2 bikes i have here at work in the warehouse.

dead stock, motor never been out of frame 75:



and my lightweight. I need to clean this, yeesh (at least it proves i actually ride it) 



no numbers on case on either. prob was done at a shop at some other time? or they quit doing it because it didnt matter? who knows. But ive never seen it on a stock unmolested set of cases. i can check the R5 tonight. 

[Greaser Greg]

That's what I thought, doesn't matter so they stopped stamping. Pic is from 71 cases.

[m in sc]

i'll check my 70 R5, its serial #2000 so in the 1st run.  Im 99% sure it doesnt have it either.

[Diablo007]

Hmm, maybe I'll have 2 numbers matching RD350's...was going to sell one but now maybe not.

[rodneya]

Banshee cases are still sold by yamaha as a set. They are machined as a pair
All you can do is trial fit mismatched cases.
Best case the crank spins freely, worst case the crank binds. Somewhere in the middle and you actually run them and your bearings don't last very long.

[m in sc]

its never been verified they are machined as a set, but they are sold as a set. This conversation has come up a few time son forums over the years.

I've never had a crank bind with mismatched cases.  if it had plain bearings would be a totally different scenario. for example, the primary and crank gear -are- factory marked as a pair, but not cases. that should tell you something. as far as those cases greg has, beats me but ive never, ever seen that on motors from the factory. -maybe- replacement cases had it, but never stock ones that were on bikes, ever.