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The 2-Stroke Garage => Turning Wrenches => Topic started by: Greaser Greg on November 27, 2019, 09:46:05 PM

Title: Knock pins R5B
Post by: Greaser Greg on November 27, 2019, 09:46:05 PM
So I opened this new project motor today and there are no knock pins on the crank bearings. What's up with that? May not be the original motor to the bike? Rd motor?
Title: Re: Knock pins R5B
Post by: Jspooner on November 27, 2019, 10:19:24 PM
Do you mean the locking or retaining pins in the outer race? Someone probably rebuilt the crank with non OEM  bearings.
Title: Re: Knock pins R5B
Post by: SUPERTUNE on November 27, 2019, 10:32:54 PM
Are you speaking of the locator pips on the main bearings?
Not needed on RD's crank main bearings.
Yamaha did that as standard for a lot of engines to clock the
outer race for models that have oiling holes on the outer race.
RD's don't need them for location. The oil holes are in between
the lab seal or outer seal and not needed as RD main bearings are a
C3 rated bearing.
So the pip means nothing.
Chuck
Title: Re: Knock pins R5B
Post by: SUPERTUNE on November 27, 2019, 10:38:33 PM
So yes, like Joe said...was rebuilt before using non oem Yamaha bearings.
Title: Re: Knock pins R5B
Post by: Greaser Greg on November 27, 2019, 11:23:13 PM
Ok great, thx.
So I'll just fix this, and this!
Title: Re: Knock pins R5B
Post by: Greaser Greg on November 27, 2019, 11:26:50 PM
Quote from: Jspooner on November 27, 2019, 10:19:24 PM
Do you mean the locking or retaining pins in the outer race? Someone probably rebuilt the crank with non OEM  bearings.
Yes, silly manual calls them knock pins. :bang:
Didn't see any on inner bearings either.
Title: Re: Knock pins R5B
Post by: Greaser Greg on November 27, 2019, 11:28:55 PM
Quote from: SUPERTUNE on November 27, 2019, 10:32:54 PM
Are you speaking of the locator pips on the main bearings?
Not needed on RD's crank main bearings.
Yamaha did that as standard for a lot of engines to clock the
outer race for models that have oiling holes on the outer race.
RD's don't need them for location. The oil holes are in between
the lab seal or outer seal and not needed as RD main bearings are a
C3 rated bearing.
So the pip means nothing.
Chuck
Never know what you'll get used sometimes. Do you use non Oem for inner bearings in your crank rebuilds?
Title: Re: Knock pins R5B
Post by: m in sc on November 28, 2019, 07:17:06 AM
they aren't available any more.  doesnt mean its a bad thing.

I sold a friend a bottom end once, had a bunch of spares and he needed one, and it had flat roller tz bearings on the crank when he opened the cases .
Title: Re: Knock pins R5B
Post by: SUPERTUNE on November 28, 2019, 08:45:42 AM
You can still buy OEM Yamaha RD main bearings, too pricey, like almost double over the aftermarket high quality "Made in Japan" bearings I use in my rebuilds.
This allows for other upgrades to spend $$ on like using the RM125 rod bearings for the RD cranks.
Chuck 
Title: Re: Knock pins R5B
Post by: rodneya on November 28, 2019, 10:34:47 AM
Quote from: m in sc on November 28, 2019, 07:17:06 AM
they aren't available any more.  doesnt mean its a bad thing.

I sold a friend a bottom end once, had a bunch of spares and he needed one, and it had flat roller tz bearings on the crank when he opened the cases .

You need to run straight cut gears behind the clutch if you want to use TZ bearings or they wont last very long
Title: Re: Knock pins R5B
Post by: m in sc on November 29, 2019, 03:07:30 PM
oh, they were in there, basket and the primary, i was like 'wtf' :umm:. I was shocked when i saw it. was kinda pissed, i sold it cheap too. But, a good friend so was OK.  :metal:


i though the oem ones were discontinued. Huh, learned something.