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The 2-Stroke Garage => Turning Wrenches => Topic started by: ElFuegoBlanco on July 22, 2020, 07:59:45 PM

Title: RD400 re-assembling crank case, mystery piece
Post by: ElFuegoBlanco on July 22, 2020, 07:59:45 PM
I came across this piece when disassembling the crankcase on a '76 RD400. I set it aside in a bag, but never did figure out what it went to. It's not quite a half circle. It's slimmer than a half moon clip. It's not bendable and doesn't appear like it snapped. I've checked all the washers and circlips on the gears and I'm stumped.
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: 27 Cycles on July 22, 2020, 08:12:13 PM
Looks to me like the shim that goes on the kickstart shaft before you put on the clutch cover.  Not unusual for them to get left/lost in there.  Probably went through some gears and that's what broke it up.
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: ElFuegoBlanco on July 22, 2020, 09:09:44 PM
Quote from: 27 Cycles on July 22, 2020, 08:12:13 PM
Looks to me like the shim that goes on the kickstart shaft before you put on the clutch cover.  Not unusual for them to get left/lost in there.  Probably went through some gears and that's what broke it up.

You're a genius! I picked up the clutch cover for the I-don't-know-how-manyth time, turned it over, and the other half fell to the ground. Mystery solved!
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: patastinky on July 22, 2020, 09:13:31 PM
True detective  8)
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: ElFuegoBlanco on July 22, 2020, 09:49:29 PM
It's really hard to tell from the fiche, but it looks like the part is #12 in this diagram https://www.yamahapartshouse.com/oemparts/a/yam/500419bdf8700209bc78557c/kick-starter (https://www.yamahapartshouse.com/oemparts/a/yam/500419bdf8700209bc78557c/kick-starter)

Now, of course, there are 2 #12 in that diagram:
12Washer, Conical Spr
90208-20022-00

12Washer, Wave
90206-20058-00

One of those is in tact. Neither appears to be available anywhere. In fact, I can't even find a picture of either of those part numbers online. So my next question is this- is it reeeallly necessary?
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: SUPERTUNE on July 24, 2020, 11:56:54 PM
Wrong,
Not on the kick starter shaft...
It's the wave shim on the tach/starter idle gear to the clutch hub gear.
Goes on the shaft first, then the gear, then a flat washer shim and then the circlip.
I like to just throw them away and buy the flat washer shim to replace the wave one, will never break again!
Chuck
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: ElFuegoBlanco on July 25, 2020, 11:57:01 AM
Quote from: SUPERTUNE on July 24, 2020, 11:56:54 PM
Wrong,
Not on the kick starter shaft...
It's the wave shim on the tach/starter idle gear to the clutch hub gear.
Goes on the shaft first, then the gear, then a flat washer shim and then the circlip.
I like to just throw them away and buy the flat washer shim to replace the wave one, will never break again!
Chuck

I actually have that wave shim. I thought the same thing, but it was still in tact and stowed away neatly when it was disassembled.
Which leaves only the wave shim on the kickstarter assembly. Is there a replacement for the obsolete kickstarter wave shim that you know of? I ordered a NOS RD350 shim (90206-25029) in hopes it would fit, but it looks like the diameter is larger.

Thanks
Rob
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: ElFuegoBlanco on July 25, 2020, 07:50:42 PM
A thousand apologies, Chuck. I misread your reply and you are (as usual) 100% correct.

Are you saying you replace it with the same flat washer from the end of the shaft? (#41 in the diagram)

Unfortunately, I'm still missing the other wave washer for the kick starter as well. Any advice on that one?

Thanks again and sorry for not listening the first time.

Rob
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: SUPERTUNE on July 25, 2020, 08:56:15 PM
Hi Rob, Only 1 apology is needed!
Yes, to using 1 of the #41 shim to replace the breakage prone wave washer, still will use a #41 outer one with the clip
Yes, you can use a RD350 shim in place of the 2 spring washers that came on the 400's kickstart shaft.
I have to stock these shim washers due to the wave washers broken or worn badly and you would be surprised at how many RD 400's and 350's kickshaft shims are missing when I do rebuilds!
Chuck
Title: Re: RD400 re-assembling crank case, mystery piece
Post by: ElFuegoBlanco on July 26, 2020, 12:10:52 PM
Thanks again. Parts are on order.