RD400 crank install question

[1976RD400C]

Koyo max Load 8 ball banshee crank bearings are only about $30 each and come with an o ring. Quality bearing and no worries about a locating pin or locktite

I ended up pulling my cases apart again and I'm gonna send the crank to John Ritter. Are these the right bearings, and can they be used to replace all 4 (inner and outer)?
https://www.amazon.com/Yamaha-Banshee-Crankshaft-Bearing-6305NRC3/dp/B07PYKD3BG

The 2 inner bearings are different from the 2 outer bearings. The inner ones have a bigger ID.

[bitzz]

The 6305N are the inside/center, and you need 6206 for the outside
The bearings in your link are "C" clearance bearings, if you use those be SURE the 6206 you order are "C" also 

[JBeasty]

So I found these, but they appear to be 9 ball? Maybe it's not the actual representative image, but when I image searched 6206 they all look like 9 ball. https://www.amazon.com/Koyo-Single-Groove-Radial-Bearing/dp/B000MNC6C0

[bitzz]

The inner ones don't need the circlip groove.
If you're using C3 bearings, look for 6206-C3. The "N" suffix denotes a groove

... I think they're out of stock everywhere. You can use a SKF EXPLORER 6206-C3 , which is the equivalent in performance.
Unless you're doing something weird with your RD, the standard bearings are fine. You don't need up-rated bearings, you don't need C3.

[1976RD400C]

Are you trying to save some money? Why not get OEM bearings with grooves and pips? 93306-20621 inners, 93306-30549 outers

[JBeasty]

Thanks guys. The "old" inner bearings on my crank do have the circlip groove - so it must have been rebuilt at some point using the incorrect bearing? Is there any negative to just using one with the groove? The reason I'm trying to go with Koyo is that's what John Ritter recommended, and he said something about using O-rings in the grooves. I'd ask him, but he's off for the next week or so. Also, I'm finding the Koyos are ~ $15-25 a piece, so not too expensive. I'm guessing the extra ball in the inner bearing is due to the larger ID?

Just to give an idea of where this build is going: John is also doing stage 1 porting on my cylinders, cutting my heads to correct squish, and port matching the intake manifolds. The carbs are 30mm(?) Mikunis, and I'll probably go with a Y-boot and foam filter. The pipes are of unknown brand, Mark (m in sc) thinks they may be pipelines?

[bitzz]

The RD series inner OEM stock crank bearing had a pip or dimple on the outside, a little knob that stuck out that sat in a slot in the cases. BE AWARE OF THEM IF YOU USE STOCK BEARINGS.
The idea is if you spin a bearing, the little "pip" is going to stop the bearing from spinning.
PERSONALLY I am not a big fan. If you spin a bearing at speed, that "pip" digs a nice trench in your cases and more often than not ruins the cases.
You can use "N" bearings on the inners and put Orings in the groove BUT the Oring will do absolutely nothing. (Do the math. the mass of the crank x 9000 rpm. That's a LOT of force and that's in neutral)
Don't put anything on the outside of the bearing. If your cases aren't biffed, anything you put on the bearing will be squished out, where it will do nothing but contaminate the bearing.
IF your cases are biffed, your cases are biffed. All the glue in the world ain't gonna fix it.

The Koyo with 8 balls is an uprated bearing. It's performance specs are higher, (higher RPM limit, higher dynamic and static load, that sort of thing) (that you don't need) than your average bearing like the stock one... and the reason we all recommend it is it's $15. The SKF Explorer equivalent is $35. The SKF not Explorer,or FAG or Timken  bearing is $25, which would be equivalent to the stock bearing, which is Nachi (if you're lucky) or NSK  (IIRC)which is $13 (without the "pip"). OEM with the pip is $65

[1976RD400C]

Here's some pics of my pipes that I am quite sure are Pipelines

[m in sc]

those look exactly like mine.

[JBeasty]

Here's mine on the bike, before ending up in the rafters.