I put new outer main bearings on my RD crank, and it rocks just a little bit resting in the bottom case. It's the bearing on the left side (gen side) that doesn't use the 1/2 circlip. I can press down on the outer shaft and make it drop down a bit. If I put the top case on and press down on it, it nearly goes away. I'm thinking (hoping) it will go away entirely when I install the new seals and torque down all the top and bottom case bolts/nuts. Still, it has me concerned. I pressed that left bearing on as far as it could go. There is a slight gap between the bearing and the side of the housing (you can see it in the second pic) - Can you press them on too far?
no you can't. its fine. do a test bolt together of the case w no sealant, check for free spinning, I'm sure its fine
Awesome! Thank you Mark!!
Do those bearings have the little locating pins? are the centre ones in their pockets?
After setting the crank in the lower case I take a wooden hammer handle and tap the bearings and center seal down so it settles in nice.
Quote from: rodneya on August 25, 2022, 10:50:07 AM
Do those bearings have the little locating pins? are the center ones in their pockets?
^ this, but i assumed you knew that. good point though.
Quote from: rodneya on August 25, 2022, 10:50:07 AM
Do those bearings have the little locating pins? are the centre ones in their pockets?
The new outer bearings don't have the locating pins, and the center ones are in their pockets. But don't assume I know anything :huh:
Quote from: 1976RD400C on August 25, 2022, 05:51:50 PM
After setting the crank in the lower case I take a wooden hammer handle and tap the bearings and center seal down so it settles in nice.
I will give that a try, thanks :like:
Quote from: JBeasty on August 27, 2022, 03:39:19 PM
Quote from: rodneya on August 25, 2022, 10:50:07 AM
Do those bearings have the little locating pins? are the centre ones in their pockets?
The new outer bearings don't have the locating pins, and the center ones are in their pockets. But don't assume I know anything :huh:
What are you using on the flywheel side to stop the bearing spinning in the case if it does not have a locating pin?
So I've read 2 schools of thought on this. One is that if the bearing freezes and it has the locating pin, it'll just tear up your case. And the other is the bearing can potentially spin around in the housing (if it doesn't have the pin) causing damage that way. In any case, apparently people have done it both ways without issue? I went ahead and got some cheaper NACHI bearings with no pins. Hopefully I won't regret it :undecided:
chuck q used to talk about this. just use a tiny drop of loctite on the bearing saddle in the bottom case. itll be fine.
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
Thanks guys. Probably should have asked. I'm trying not to ask about every little thing. I'll do the loctite trick.
Loctite green, retaining compound 680. Just a tiny drop as Mark said. I saw a picture of someones with it gobbed on... don't do that lol.
Quote from: rodneya on August 29, 2022, 05:53:04 PM
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
Quote from: JBeasty on December 29, 2022, 02:02:59 AM
Quote from: rodneya on August 29, 2022, 05:53:04 PM
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.
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
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
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.
Are you trying to save some money? Why not get OEM bearings with grooves and pips? 93306-20621 inners, 93306-30549 outers
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?
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
Here's some pics of my pipes that I am quite sure are Pipelines
(https://i.ibb.co/ZMCtjWc/pipelyne2.jpg) (https://ibb.co/Vq8r12M)
(https://i.ibb.co/ZRrKdqZ/pipelyne1.jpg) (https://ibb.co/RGKP2R5)
those look exactly like mine.
Here's mine on the bike, before ending up in the rafters.