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The 2-Stroke Garage => Turning Wrenches => Topic started by: rd400greenhorn on October 18, 2020, 04:46:40 AM

Title: Rd250 frame rd400 engine
Post by: rd400greenhorn on October 18, 2020, 04:46:40 AM
Hi guys
So, i have a lot of parts i would love put into work( a working motorcycle)

Rd400 frame are Hard to Come by, but a guy had a Rd250. Frame

So, is that frame as the rd400, iam Thinking with rd400 engine, front end, swingarm, rims etc etc
Title: Re: Rd250 frame rd400 engine
Post by: Diablo007 on October 18, 2020, 05:06:28 AM
Are you looking for an  early RD400, or RD400F frame.  I have an early frame with the seat rails cut/shortened, apparently the previous owner was going to build a cafĂ© racer.  I would like to keep the braced swingarm, but could be persuaded to include it.  I really don't want much for the frame itself as it does not have a title, problem is it will ship from Hawaii.  Last frame I sold and shipped to California was a TZ350 frame, shipping was somewhere around $175.  Make an offer if you're interested.  In reality all I'm looking for is some compensation for the time and effort to make the custom shipping box out of cardboard, which was a chore for the TZ.
Title: Re: Rd250 frame rd400 engine
Post by: Diablo007 on October 18, 2020, 05:14:19 AM
I just realized there may be an RD400F frame at the shop somewhere also.  There are also complete RD400F's but those would most likely be cost prohibitive to ship from Hawaii.  Shipping on the RD400F frame would be in the same ballpark, though that belongs to my friend, he would know if it has a title and would also have to set the price.  Let me know if you're interested.
Title: Re: Rd250 frame rd400 engine
Post by: rd400greenhorn on October 18, 2020, 05:55:15 AM
Hi
Very kind of you, but I live in Denmark, so i think it Will cost quote a bit to get a frame over 😁
Title: Re: Rd250 frame rd400 engine
Post by: teazer on October 18, 2020, 12:04:27 PM
IIRC, the 400 motor sits a little further forward than earlier RDs and ss far as I know, the difference between a late model RD250 frame and early one is that the 400 has a removable front engine mount to allow the taller RD motor to be fitted with the heads on.

What I don't know is if the later 250 also changed to the 400 engine position or kept the earlier geometry. 

The 400 motor should fit without any issues and if you fit a longer swingarm, it should help to keep the front end down.
Title: Re: Rd250 frame rd400 engine
Post by: stresa on October 18, 2020, 06:32:43 PM
Quote from: teazer on October 18, 2020, 12:04:27 PM
IIRC, the 400 motor sits a little further forward than earlier RDs and ss far as I know, the difference between a late model RD250 frame and early one is that the 400 has a removable front engine mount to allow the taller RD motor to be fitted with the heads on.

What I don't know is if the later 250 also changed to the 400 engine position or kept the earlier geometry. 

The 400 motor should fit without any issues and if you fit a longer swingarm, it should help to keep the front end down.
European C/D 250 and 400 and E/F 250 and 400 share the same frame
Regards Uwe
Title: Re: Rd250 frame rd400 engine
Post by: rd400greenhorn on October 19, 2020, 03:19:10 AM
Can anyone see if this looks right? The 250 frame picture i got
Title: Re: Rd250 frame rd400 engine
Post by: Diablo007 on October 19, 2020, 03:53:34 AM
Wow, Denmark.  Yeah, shipping would definitely be out of the question.  Too bad.  I just want to find the frame a home.  I have enough projects already, I don't need to add a new model to the mix.  I saved it from a dumpster, I don't want it to end up in one anyway.
Title: Re: Rd250 frame rd400 engine
Post by: 1976RD400C on October 19, 2020, 07:00:15 AM
That looks like a US RD400 frame with the bracket for the rear master cylinder and plastic fender.
Title: Re: Rd250 frame rd400 engine
Post by: stresa on October 19, 2020, 07:58:28 AM
Quote from: rd400greenhorn on October 19, 2020, 03:19:10 AM
Can anyone see if this looks right? The 250 frame picture i got
That's a C or D frame, depending on the frame number
Regards Uwe
Title: Re: Rd250 frame rd400 engine
Post by: rd400greenhorn on October 19, 2020, 12:44:02 PM
What about the pipes and pegs? Any problems there?
Title: Re: Rd250 frame rd400 engine
Post by: stresa on October 19, 2020, 04:09:48 PM
Quote from: rd400greenhorn on October 19, 2020, 12:44:02 PM
What about the pipes and pegs? Any problems there?
If you mean the C or D frame. Exhaust and pegs are the same on both models
Regards Uwe
Title: Re: Rd250 frame rd400 engine
Post by: rd400greenhorn on October 20, 2020, 12:57:22 AM
Yeah
So i thought about if there was Any conserns regarding pipe mounting on a 250 frame with a 400 engine
Title: Re: Rd250 frame rd400 engine
Post by: pidjones on October 20, 2020, 07:44:46 AM
You can pretty well see similarities and differences in the parts diagrams, since they are common between the two. Just look at the accompanying matrix to see application.
Title: Re: Rd250 frame rd400 engine
Post by: Diablo007 on October 23, 2020, 12:59:50 AM
Oddly enough; Classic Motorcycle Mechanics, May 2020 talks about this in the article on page 8, 'Air Cool!'.  Not how to put the 400 engine in the 250 frame however, just that it was a popular mod back in the 'day'.
Title: Re: Rd250 frame rd400 engine
Post by: dusty350 on October 23, 2020, 02:51:28 AM
My current project is a European 400E engine in a 250D frame. In fact, my last 400 build 11 years ago was the same. It slots straight in, with no modding needed.

Dusty ;D
Title: Re: Rd250 frame rd400 engine
Post by: rd400greenhorn on October 23, 2020, 01:20:29 PM
Sounds good dusty 👍 :metal:

I Will find out soon i think, wheter i can get a rd400 frame or a 250