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The 2-Stroke Garage => Turning Wrenches => Topic started by: JBeasty on March 18, 2023, 10:03:42 PM

Title: Build RD motor in Frame?
Post by: JBeasty on March 18, 2023, 10:03:42 PM
I have the bottom end of the engine assembled, no side cases. I'd like to put it in the frame and build from there because it's kinda heavy and I'm a one man show. Also, don't want to scratch up my freshly painted side cases. Any reason I shouldn't do it that way?
Title: Re: Build RD motor in Frame?
Post by: rodneya on March 18, 2023, 10:53:03 PM
No prolem at all doing it that way
Title: Re: Build RD motor in Frame?
Post by: Striker1423 on March 19, 2023, 09:24:16 AM
If running points and its attached... just be careful with it. But, if you assemble the charging system afterwards, no issue.
Title: Re: Build RD motor in Frame?
Post by: kramdua on March 19, 2023, 10:40:12 AM
i have done several different bikes that way. much easier on back and paint.
Title: Re: Build RD motor in Frame?
Post by: JBeasty on March 19, 2023, 05:12:08 PM
Awesome! Thanks guys.
Title: Re: Build RD motor in Frame?
Post by: RDryan on March 20, 2023, 07:42:36 AM
+5 yeah your good to go, I did the same thing with mine.  :thumbs:
Title: Re: Build RD motor in Frame?
Post by: m in sc on March 20, 2023, 09:17:45 AM
yup. no issues to speak of. I usually do it this way as well, however we did matts 400 motor out of the bike (top end at least, left the  sidecovers off) because it was going to sit for a few mos till the frame came back and didn't want to leave the crank area exposed.  :twocents:
Title: Re: Build RD motor in Frame?
Post by: Brad-Man on March 20, 2023, 12:02:36 PM
If you are putting an RD400 engine in an RD350 frame do you have to have pistons and cylinders assembled or can you attach Pistons and install cylinders with case in frame.

I'm thinking I remember that cylinders and Pistons need to be assembled first, but my memory is getting suspect...

Thanks.
Title: Re: Build RD motor in Frame?
Post by: m in sc on March 20, 2023, 12:07:05 PM
ive heard people say it can't be done.. but it can. you just loosen the front motormount bolts, and the rear upper one if its being used and you can -just- squeeze the cyls on. heads are easy. but its tight.
Title: Re: Build RD motor in Frame?
Post by: Brad-Man on March 20, 2023, 08:14:09 PM
Thanks.

I'll try it.

I just have to blast the fins and paint the cylinders before I start to put the engine in....
Title: Re: Build RD motor in Frame?
Post by: 1976RD400C on March 21, 2023, 06:28:06 AM
On the 400 there is a flat spot made on the underside of the frame rail, to allow enough clearance, so you can just get the cylinder on.
Title: Re: Build RD motor in Frame?
Post by: pidjones on March 21, 2023, 07:11:27 AM
I'm a 70 year-old weakling, and never considered the RD400c very heavy. Having it in-frame might help torquing a few bolts, but I rebuilt mine on the bench and stored it in a plastic storage bin until the frame was ready. Maybe all the GL1000s I've wrestled changed my perspective.(https://uploads.tapatalk-cdn.com/20230321/b79d12244a4928ccee76ef7d4cbece2b.jpg)
Title: Re: Build RD motor in Frame?
Post by: Striker1423 on March 21, 2023, 08:41:22 AM
This GT750 motor has me questioning my arm strength. I do not look forward to hauling it up the basement stairs once built. It went down in pieces. I just like that the basement is somewhat temperature controlled for motor rebuilds... as Michigan does its Spring/Not Spring cycle.