suzuki RM with an XT250 motor?

[ghostdancing]

hello people of the yellow bikes, i'm investigating on the possibility to squeeze an XT250 motor in an RM chassis.. i like the late twin shocks suzies (78\80).. are the frames similar in these 3 model\years (78\79\80)? i assume the 400 is the larger frame, correct?

any of you guys can take a couple of measurements on your bike so i can understand if my motor can fit the cradle?

[80-85 husky]

your biggest drama is getting the countershaft sprocket to line up with the swingarm pivot. ive never done this so this is just a general observation of all those conversions ive seen over the years. some terrible things happen if they don't line up..seen that!

[LWC82PE]

79/80 RM250 frame is the same as 1980-82 PE250 & 400 frame, except for minor brackets for electrical items and rear loop. Also left vertical down tube  from footpeg up has a bend in it to to allow space for the PE battery holder next to the carby which RM does not have.  I would expect 79/80 RM400 frame to be the same as these frames too.

[ghostdancing]

husky: yes that's the first point to get done in a motor swap..

so RM 250\400 shares the same frame, correct? i see there was also a suzuki RS 175\250:

https://www.google.it/search?q=suzuki+rs+250+1982&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwinus-25PjTAhXpJZoKHbMQBRsQsAQIJQ&biw=1280&bih=640#imgrc=wUlHVqnhou6MEM:

pretty toy indeed.. i assume it's the same machine with different dress..correct?

[Momus]

If you have the skills and gear to fit a tall, relatively bulky 4 stroke in an RM/PE  a few minor frame variations should not worry you. It is going to involve fairly major surgery to the lower cradle to get the all impotant countershaft sprocket to swingarm pivot right.

[LWC82PE]

RS250 frame can be considered same as 79/80 RM & 80-82 PE
RS175 is based around RM125/PE175
They are pretty much parts bin specials although a few items were made especially for the RS.

[ghostdancing]

are the RM\PE so tall? i must admit that never saw one in real life.. anyway my the motor is not exactly a ripper with less then 20 ponies (enough for me in any cases)

actually i havent got great fabrication skill, but you must start somewhere.. anyway i work on my bikes since a couple of decades.
..i love work in the shed just as when i was younger.. let's say that my builds\projects are not for racing or agressive riding: it's more love for motorbikes and enjoing working on them

the XT frame do not has the low cradle (it's an open layout like some hondas of the same era (Xl\xr 250\500 s\r) so i do expect major modification of the lower suzuki frame design.. only dont want modify the main downtube.. so i figure the first thing to see it's

-the actual room in the frame in the front\rear direction, 
- the actual possibility to set the swingarm pivot trough the motor (as in the XT original design)
-the position of the front sprocket in the 2 motors (distance sprocket - center axis of motor, for example) to have an idea of how put the sprocket in the correct place

i saw in the web ( in the french version of this forum..)a very nice and well done hibryd RM 1980 with a suzuki 370 fourstroke in, the builder its' french and france people dont like english.. that's why i didnt asked info to that guy

[80-85 husky]

yep they can be tall from 1980 on..mate has a 82PE and he had the shocks shortened a tad to make it easier to foot in the scrub...he is 5'10 ish

[James Lee]

Ive checked this out and from what Ive seen you will need to cut out the bottom rails to get the counter low enough,also the down tube needs to be bent forward.I haven't done the conversion but seriously considered it until it went in the too hard basket and I ended up fitting IT250 swing arm etc to the XT,its not finished yet and wont be anything like an RM in handling,unless you have a rolling RM on hand you might find yourself buying a heap of parts you cant use,which is fine if you have the spare cash,Im not trying to talk you out of it,go for it,should be an awesome bike if you finish it.

[evo550]

I have a T&T article where a guy fitted a xt 500 motor to a full floater rm 465 chassis...lots of work.
If your hell bent on putting that motor in another chassis a twin shock Husky may be a better option. They seem to have alot more room in the engine bay.

[80-85 husky]

the 80 - 83 huskies are a popular xt xr engine conversion. no shortage of these about... tin tanks are good with hot fourstroke engines just underneath imo

[Ekka]

What evo550 said go husky frame , I did it with a tt 250 motor look at the Yamaha section topic mini hl project

[ghostdancing]

tnx guys for sharing your experience here.

ekka: of course i saw your bike.. it's the same idea (but your beast it's made for serious race, regardless to the beauty factor, if you know what i mean).. that frame should be cromoly.. how it was welding in that? did you used MIG?

your frame it's  a later twinshock husqy  (that one that comes with ITC shock very layed down.. 82?).. correct? actually i'm considering to put a bid here:

http://www.ebay.it/itm/332221844457?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

from the pic looks like there is plenty of room in that cradle...

back to suzukis: do the previous RM series (76 - 78) frames are larger at the cradle (more vertical downtube)?

[80-85 husky]

probly less as they had down pipes

[ghostdancing]

http://www.motodacross.com/suzuki/rm500/1976A.jpg

i mean this bike..