1983 RM 250 ?s

mxnut23
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mxnut23
Edited Date/Time 1/27/2012 4:17pm
I have a 83 rm 250 and I would like you guys to weigh in on what you would do to it for Vintage MX racing. I have heard the 82 motor is better, my question is how? The 83 has no bottom end what so ever that is where I need the most help. The suspension is awesome it makes me feel like a hero. Thanks in advance.
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CamP
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CamP 7/3/2009 5:39pm
7/3/2009 5:39pm
Act quickly and get this 82 head.
Matt Fisher
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Matt Fisher 7/3/2009 6:50pm
7/3/2009 6:50pm
You could have the 83's head re-shaped pretty easily too.
Craze
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Craze 7/3/2009 7:38pm
7/3/2009 7:38pm Edited Date/Time 7/3/2009 7:40pm
mxnut23 wrote:
I have a 83 rm 250 and I would like you guys to weigh in on what you would do to it for Vintage MX racing...
I have a 83 rm 250 and I would like you guys to weigh in on what you would do to it for Vintage MX racing. I have heard the 82 motor is better, my question is how? The 83 has no bottom end what so ever that is where I need the most help. The suspension is awesome it makes me feel like a hero. Thanks in advance.
The 82 head is the way to go!!!

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GraemeM
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GraemeM 7/4/2009 2:44am
7/4/2009 2:44am
Yep, the 82 head is what you need. Back in the day I raced an 82, and I found the DG pipe helped the mid-range too.
croom mx
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croom mx 7/4/2009 6:18am
7/4/2009 6:18am
I owned a 1982 Rm250 very fast bike , great rear suspension , front forks were too small 38 mm had alot of flex. If you put modern forks on that bike it would be nice. But then you could buy a 2008 rm250 2 stroke as well?
Wandell
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Wandell 7/4/2009 2:09pm
7/4/2009 2:09pm
I had an 83. The only difference in the engine was the new cylinder head that lowered compression and the timing was retarded a couple of degrees. If you install an 82 head and advance the timing you will have a rocketship with better forks and front brakes than the 82 bike.
mxnut23
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mxnut23 7/4/2009 2:13pm
7/4/2009 2:13pm
Thanks everyone!! I am in the process of acquiring the 82 head!!
CamP
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CamP 7/4/2009 2:30pm
7/4/2009 2:30pm
Wandell wrote:
I had an 83. The only difference in the engine was the new cylinder head that lowered compression and the timing was retarded a couple of...
I had an 83. The only difference in the engine was the new cylinder head that lowered compression and the timing was retarded a couple of degrees. If you install an 82 head and advance the timing you will have a rocketship with better forks and front brakes than the 82 bike.
I learned that the '82 crank was also lighter.
mxnut23
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mxnut23 7/4/2009 9:05pm
7/4/2009 9:05pm
Hey CamP how did you come up with your number?? Assuming your profile pic is you. I also use the 23. Thanks for the link to head. I missed it but there were no bids so I have emailed them about purchasing one from them or if they are auctioning it off again.
CamP
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CamP 7/4/2009 9:14pm
7/4/2009 9:14pm
It was my basketball number when I was in 4th grade. I got a '73 XR75 the same year and it stuck.

The head will probably come up again. That was their second auction. The first one it was mislabled as an '83 head. I was surprised nobody snapped it up during the last auction. Hopefully you can get it from them.
mxnut23
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mxnut23 7/12/2009 6:40pm
7/12/2009 6:40pm
I ended up winning that head. Hopefully it gets here before the weekend and I can run it this Sunday!! Thanks everyone for the info!!! I got my number from my kids birthdays all are on the 2nd or the 3rd( there are 4 kids) and David Bailey around 84 I think.
jimmie
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jimmie 7/12/2009 9:56pm
7/12/2009 9:56pm
Pretty cool bike. My recollection of that model (which I owned 83-86) was that the forks were very harsh on slap down landings, which were common for me back then. The double leading shoe front brake was bad a**. As close to a disc brake as you could get......................unless you liked the color green. The dual air filters were a small price to pay for the awesome floater suspension, truly a remarkable design.

Enjoy the heck out of that ride.
mxnut23
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mxnut23 7/17/2009 7:35pm
7/17/2009 7:35pm
Head is now installed and very anxious to ride it sunday at the Vintage races. The combustion chamber is way different. I will let you guys know how it goes after sunday.


Thanks again everyone!!
CamP
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CamP 7/17/2009 8:30pm
7/17/2009 8:30pm
Look forward to hearing how it compares to the milder 83 power delivery. Last week I was talking to Eric at Pro-Form pipes and he says he can actually rework the 83 head to produce a powerband that works better than either stock head. He says it has 82 top end power with 83 low and midrange. I have a spare 83 engine and once I recover from my current expenditures, I want to send the head to him to see what he can do with it. The nice thing about these old bikes is that they are relatively inexpensive to modify.
mxnut23
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mxnut23 7/19/2009 7:00pm
7/19/2009 7:00pm
I loved the new power but the tranny did not. I was sitting waiting for my second practice and I reved her up a little to clean her out and bam it went into gear. I thought some one was messing with me but I soon found that it wouldn't shift up or down. I was able to pull the clutch in and start it and putt back to my pit but it was in maybe 3rd or 4th gear. Anyone have any Ideas?? My first time entering a race and getting the big DNS, that sucked oh well !!

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