77 RD400 Crank Seals (solved) & Rotor Removal (solved!)

[motodreams]

First time working on one of the 400's.

Architecture looks similar to the watercooled versions.

Can someone please confirm the cases have to be split in order to replace the crank seals?

Thanks!

[2 Stroke Jamoke]

Yep, you should definitely do the other seals while your in there

[2steve]

Both crank seals have a bead on them that rests in a corresponding groove in the case halves.  Probably not impossible to slightly separate the halves, dig out and replace, but not recommended.  Seems like Chuck Q mentioned long ago that it could be done when in a pinch.

You can get the seal kit from John at Economy Cycle and add that oddball crank o-ring with the keyway block seal on it for pretty cheap.

I'm interested to see what your upper case half looks like where the drive sprocket shaft bearing is...

[SUPERTUNE]

I always split cases on RD's...only R5 without the ribs can be done on the mag side for crankshaft seals,  the other seals as the pushrod and countershaft seals yes, no problem with those, just debur the edges before installing new ones.
C

[motodreams]

Dealing with a motor that is in good shape but sitting for about 8 years so it needs seals as preventative.

Figured the cases had to come apart like RZ/LC.  No biggie, just a couple more hours.

[motodreams]

What's procedure on the actual generator rotor?  Used to electronic CDI not points type.  Try and avoid destroying this thing.

So far motor looks awesome. 

Last item to remove before splitting cases.  Doesn't look like they have been apart previously.

[quocle603]

What's procedure on the actual generator rotor?  Used to electronic CDI not points type.  Try and avoid destroying this thing.

So far motor looks awesome. 

Last item to remove before splitting cases.  Doesn't look like they have been apart previously.

Eric from Oilypipes helped me with this. Take your top mount bolt and thread it in with lube and it will push out the generator, dont lose the keyway! Put it all back on with the magneto and you're all set.

[2steve]

Specifically the top rear engine mount bolt - and, assuming your crank gear and clutch basket are still on, stuff a rag in the gears on the other side.  I put a box end on it and tapped it with a hammer till it started sliding out.  Then, didn't know about unhooking the wiring and texted Mark.  He told me to chase the wires up to their hook ups in the area around the fuse box.  Here's the end result:

[motodreams]

This worked great.  Getting the generator off the crank seems even easier than removal of a flywheel with the flywheel tool on a CDI once you know what you are doing!

Thanks for the help guys!

[quocle603]

Gotta love it when you don't need special tools.