Author Topic: Wanted RM 250 B motor  (Read 5888 times)

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Offline Nipper

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Wanted RM 250 B motor
« on: September 16, 2011, 01:19:01 pm »
Hi, I am after a motor to suit a 1977 RM 250, any condition is ok.

Offline Freakshow

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Re: Wanted RM 250 B motor
« Reply #1 on: September 16, 2011, 02:23:03 pm »
i have a  PE250B motor, my under standing is its the exact same motor.
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Offline shelpi

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Re: Wanted RM 250 B motor
« Reply #2 on: September 16, 2011, 03:46:33 pm »
Hi, all the RM250B parts will fit into a PE250B motor, if you want a list of parts to make a PE into a RM Let me know and i will give you all the details at this post. ;D

cheers

Offline Nipper

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Re: Wanted RM 250 B motor
« Reply #3 on: September 16, 2011, 05:29:28 pm »
Hi Freaky if what you say is right....and why should I doubt you, it sounds like a good alternative to me I am interested.

Offline Nipper

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Re: Wanted RM 250 B motor
« Reply #4 on: September 16, 2011, 05:31:04 pm »
Shelpi can you post the details it would be much appreciated. Have you made these changes youself to another motor before ?

Offline Freakshow

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Re: Wanted RM 250 B motor
« Reply #5 on: September 19, 2011, 12:24:18 am »
Hi Freaky if what you say is right....and why should I doubt you, it sounds like a good alternative to me I am interested.

Mate i have no idea, i was just told if you grind off the numnber you have a RM motor to fit in your frame, it just what i have heard on here a few times.

MY only suz experiances are with TM and even that is superficial and jetting only.  you would need to do your own homework on this options
74 Yamaha YZ's - 75 Yamaha YZ's
74 Yamaha  flattracker's
70  Jawa 2 valve speedway's

For sale -  PRE 75 Yamaha MX stuff, frame, motors and parts also some YAM DT1,2,A and Suzi TS bikes and stuff

Offline Doc

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Re: Wanted RM 250 B motor
« Reply #6 on: September 19, 2011, 05:25:16 am »
The PE250B/C engine will bolt in the RM250B/C/C2 frame, but the porting, crankshaft taper, ignition and transmission ratios are different. I believe the RM250 parts will bolt straight in. There maybe other differences but you'll have to wait for the PE experts to get the low down. Excuse the pun ;D

Offline Freakshow

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Re: Wanted RM 250 B motor
« Reply #7 on: September 19, 2011, 03:22:55 pm »
i also belive from memory my motor has a blank case side from factory, so it doenst actually have a serial number on it,  so i have only been told it looks like a PE250B you might even be wangling an RM as i dont have a clue.
74 Yamaha YZ's - 75 Yamaha YZ's
74 Yamaha  flattracker's
70  Jawa 2 valve speedway's

For sale -  PRE 75 Yamaha MX stuff, frame, motors and parts also some YAM DT1,2,A and Suzi TS bikes and stuff

Offline Nipper

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Re: Wanted RM 250 B motor
« Reply #8 on: September 19, 2011, 04:58:25 pm »
Thanks Doc and thanks Freakshow you guys are giving me food for thought. I need to have a look at my options which at this point are looking pretty slim. Thanks guys.

BEARVMX

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Re: Wanted RM 250 B motor
« Reply #9 on: September 19, 2011, 07:59:36 pm »
Yep got 1 complete rm250 motor 77?78? carb pipe electrics you can have the lot $350.00 the down side kick starter welded on gear shift shaft welded on was running in an rm400n that i just purchased off big k please pm me if you want it, and organise own freight thanks Bear

Offline Doc

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Re: Wanted RM 250 B motor
« Reply #10 on: September 19, 2011, 09:40:34 pm »
Gary, I didn't realize the B/C engines would bolt into the N/T frames. Mind you I've never tried with the larger capacities basing my assumption on the 125's which don't fit without mods to the mounts :-\

Offline Nipper

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Re: Wanted RM 250 B motor
« Reply #11 on: September 20, 2011, 09:04:50 am »
Thanks Bear I will PM now.

Offline shelpi

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Re: Wanted RM 250 B motor
« Reply #12 on: September 20, 2011, 12:27:11 pm »
 Hi Nip, yes i have made what i call REM250B's  and have built numeous RM ENGINES as i raced RM's as a pup and worked for kessners back in the old days,all RM components will fit PE but PE gearbox will not fit RM due to the Pe cases being machined out for the larger gears. now for the parts you will need to make a PE into a RM (REM) RM250- head, barrel, crank shaft, gearbox, stator plate rotor and PEI pack as the curve rate for ignition advance rate is differant to PE, carby and or replace all the inards with RM carby specs, all the best on your quest, if i was you i would buy that RM engine offered to you, ;D cheers

Offline Nipper

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Re: Wanted RM 250 B motor
« Reply #13 on: September 20, 2011, 01:35:25 pm »
Thanks Shelpi you are a wealth of information .I appreciate your reply.

Offline Davey Crocket

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Re: Wanted RM 250 B motor
« Reply #14 on: September 20, 2011, 09:20:33 pm »
I have a PE250B and although  love riding the bike its no motocrosser....1st gear is way too low, 4th gear is 5th on the RM so its like shifting from flat out in 3rd, missing 4th and going straight into 5th.....and 5th gear is just as big a gap aswell....4th and 5th where designed for the transport stages in Enduro's.....it also makes no top end power....2nd and 3rd are perfect though....buy the RM motor as Shelpi say's.....if your a beginner and not a fast rider it would be a good learner engine (the PE).
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