'75 RD350
Please don't think this is a dumb question.......but is the bolt that retains the rotor left hand or right hand threads? I ask because it is VERY tight. I have a big 1/2" ratchet on it and haven't gotten it loose yet. I just do not want to twist it off.
I have a manual, but it doesn't address this nor have I found any info with a search.
And just to be clear; to pull the rotor (that is IF I ever get the bolt out) I use the rear engine mount bolt to push it off with? That, I found when searching for which way to twist the bolt.
Any other hints, tricks, or thoughts would be welcomed!
Thanks
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Last that I recall, its not reverse threaded. Yes, the mounting bolt will push the rotor off.
Yes, turn counterclockwise to loosen. Put a drop of oil on the threads of the bolt you use as a puller.
Thank you!
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I always use my air impact for stuff like this. Don't have to go crazy but that quick initial "braap" to jar it loose a little is a must for me...
I have impacts. I just didn't want to hit that bolt with that much energy before I had some idea of what I was doing. :lol:
I found that using my oil filter wrench is the best way to hold the rotor. Almost fits like it was made for it.
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itll hold it but usually isnt nec. its a 7mm thread. keep that in mind.
Quote from: RDDave on February 22, 2026, 12:23:21 PMI have impacts. I just didn't want to hit that bolt with that much energy before I had some idea of what I was doing. :lol:
I found that using my oil filter wrench is the best way to hold the rotor. Almost fits like it was made for it.
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Having no idea what I was doing never stopped me :devil:
Quote from: RDDave on February 22, 2026, 12:23:21 PMI have impacts. I just didn't want to hit that bolt with that much energy before I had some idea of what I was doing. :lol:
I found that using my oil filter wrench is the best way to hold the rotor. Almost fits like it was made for it.
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You could always just use a breaker bar as it maybe too much stress not enough leverage for the ratchet. So if the rotor/crank wants to move while trying to loosen the bolt you could create a piston stop with some rope coiled in one of the sparkplug holes or either buy one or make one.
back in my 20s it was a 6 pt box end wrench and a hammer. im serious. its fine. :twocents:
yep done that :dawg: If motor in bike and chain on I used to just put in gear and step on brake and use the breaker bar or big wrench. The penny in Primary gears worked too.
After knowing that the bolt is right hand threads, the impact made light work of it and of pulling the rotor. Thank you for all that information.
Now, I have the new Yamaha seal and am ready to pull the original. But before I do, tell me what I need to know about the rib on the seal. I know that the seal is meant to be installed with the cases open. Obviously, I am trying to change it without splitting the cases. Can I? I have looked with the search and at youtube but have not found anything on this. Can I actually do it without splitting the cases?
Any tips, tricks, advice would be most appreciated.
Thank you! AGAIN!
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might be a bit late, but the r5 seals do t have the rib.
I already have the RD seals. Since I now know how to access this seal and will monitor the plug; what if I 'dress down' the rib on the RD seal and try it? If, for some reason it doesn't work, I can then go with the R5 seal.
And these seals go in dry, right? I usually use some alcohol on these kind of applications. It is a bit of a lubricant, but then dries and is no longer slick.
Thoughts, opinions..................
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very carefully shave it off. when I dirty dog it like that I usually use some case sealant on the outside of the seal. most will be shaved off but some will remain. have you dug the old seal out yet?
Plan to hit it tomorrow.
I have plenty of sealants to choose from. I will use some instead of the alcohol.
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use motoseal or yamabond. do not use regular silicone
Quote from: RDDave on February 25, 2026, 10:14:13 AMAfter knowing that the bolt is right hand threads, the impact made light work of it and of pulling the rotor. Thank you for all that information.
Now, I have the new Yamaha seal and am ready to pull the original. But before I do, tell me what I need to know about the rib on the seal. I know that the seal is meant to be installed with the cases open. Obviously, I am trying to change it without splitting the cases. Can I? I have looked with the search and at youtube but have not found anything on this. Can I actually do it without splitting the cases?
Any tips, tricks, advice would be most appreciated.
Thank you! AGAIN!
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Have never actually had good luck with just pressing in that seal. Tried it many times, just ended up splitting the case and doing it and it fixed my crank seal leak 100%.