2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: Tommo on September 02, 2025, 09:42:09 AM

Title: Crank work?
Post by: Tommo on September 02, 2025, 09:42:09 AM
What's required to disassemble an RD 350 crank?
I realize there are experts who provide this rebuilding service but I was curious if this was something I could do on my own.
Thanks
Title: Re: Crank work?
Post by: m in sc on September 02, 2025, 10:23:43 AM
a press a jig runout gauges v blocks and a big brass hammer.  im serious. or just buy a replacement crank new from vitos
Title: Re: Crank work?
Post by: 1976RD400C on September 02, 2025, 10:27:41 AM
 It definitely takes some practice to have things go smoothly.
Title: Re: Crank work?
Post by: m in sc on September 02, 2025, 10:34:32 AM
true.  i did a few rd cranks, an s2 (triple) and my t500.  it's not 'bad' but times consuming. to be fair, to buy all the rebuild parts for a 250/350 crank, its within maybe 100-150 for a replacement new crank that doesn't have weights that will come loose. I've just resorted to buying new ones for the 350s
Title: Re: Crank work?
Post by: 1976RD400C on September 02, 2025, 10:49:22 AM
I've done lots of 400 cranks if anyone needs one done at a bargain price.
Title: Re: Crank work?
Post by: sav0r (CL MotoTech) on September 02, 2025, 11:20:01 AM
I find it fiddly but not difficult per se. I recently did a old Honda 300ex Odyssey crank that had been cut on, hammered on, and generally was just beat up. On top of that, the crank pin that's available is slightly too short for the crank.

That one got frustrating after a while. Managed to get it to .002" total runout and gave up. Other than that, all of the ones I have played with were pretty simple to get under .001".

That said, the Vito's crank is the way to go. I have two Yamaha cranks and one Vito's crank and by the time I build my Yamaha crank it's not much cheaper than the Vito's. The big cost of having cranks done is shipping them two directions. Vito's solves that.
Title: Re: Crank work?
Post by: RDnuTZ on September 02, 2025, 12:21:49 PM
HPR on eBay has cranks for RD350 as well. Mine were a little less overall $ cost than the 1 I got from Vito's but they are same design as OEM instead of upgraded like Vito's. Can't go wrong either way IMO. Plug and Play saves a bunch of my time which I have a finite supply of  :thumbs:
Title: Re: Crank work?
Post by: Tommo on September 02, 2025, 12:59:31 PM
Okay I see. I would just be embarrassed to send this out to anyone, it's in really rough shape.
Title: Re: Crank work?
Post by: sav0r (CL MotoTech) on September 02, 2025, 01:10:10 PM
Post some pictures so we can commiserate.

It's probably not that bad. Unless the bearing surfaces are heavily rusted/pitted it can almost certainly be saved.
Title: Re: Crank work?
Post by: paul1478 on September 02, 2025, 02:38:47 PM
my crank went from what you see in parts to the nice shinny one (not from my doing).

old_crank.jpg
good_crank.jpg
Title: Re: Crank work?
Post by: 1976RD400C on September 02, 2025, 04:31:24 PM
If something doesn't sound quite right, roll back on the throttle.  :umm:
Title: Re: Crank work?
Post by: SoCal250 on September 02, 2025, 09:50:22 PM
Quote from: paul1478 on September 02, 2025, 02:38:47 PMmy crank went from what you see in parts to the nice shinny one (not from my doing).
Chuck did great work  :thumbs:
Before any new folks get their hopes up, unfortunately he has closed his shop and is no longer doing two-stroke work.
Title: Re: Crank work?
Post by: quocle603 on September 03, 2025, 06:54:41 AM
I miss seeing chucks post and information on this forum. There are just so few people doing stuff on these things now.
Title: Re: Crank work?
Post by: NYSingh on September 03, 2025, 11:24:02 AM
Quote from: 1976RD400C on September 02, 2025, 10:49:22 AMI've done lots of 400 cranks if anyone needs one done at a bargain price.

Where in NY are you located? Might have to take you up on that
Title: Re: Crank work?
Post by: Yamanatic on September 03, 2025, 12:06:13 PM
RD crankshafts plus all the rebuild parts fit in a USPS Medium Flat Rate box: $18.50 'Click and Ship,' $21.05 OTC.
Title: Re: Crank work?
Post by: 1976RD400C on September 03, 2025, 12:11:54 PM
Quote from: NYSingh on September 03, 2025, 11:24:02 AM
Quote from: 1976RD400C on September 02, 2025, 10:49:22 AMI've done lots of 400 cranks if anyone needs one done at a bargain price.

Where in NY are you located? Might have to take you up on that

Albany