Any 79 RM250 threads?

sandman768
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sandman768 2/13/2015 1:36pm
2/13/2015 1:36pm

had bunch of hardware replated, replaced all the 35 yr old nuts with new.



replaced bogus suzuki silencer hanger with aluminum hanger off a 9o"s cr honda


rear rim & brake plate off an 81 or 82 rm 465, bolted right on, chain adjusters, axle, brake parts all replated, new chain adjuster bolts & nuts, new rear wheel bearings, found out axle is slightly bent, I will try my 84 rm axle to see if it fits, the 79 with the nuts on each end is weak.
notme
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notme 2/14/2015 9:13pm
2/14/2015 9:13pm
Lookin awesome. Where did you get the silencer? I know someone looking for one.
sandman768
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sandman768 2/15/2015 5:19am
2/15/2015 5:19am
notme wrote:
Lookin awesome. Where did you get the silencer? I know someone looking for one.
silencer came on the bike,when I bought it, I think vintage iron/ pro form pipe & silencer.
mayzo
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mayzo 2/15/2015 11:21pm
2/15/2015 11:21pm


How timely is this thread to pop up.
Picked this up on the weekend, it was for sale as a 79 but it's an 80.
It's all there, even have the factory handle bars that came on it that are strainght.
Original plastic, though faded.
Stock pipe and muffler.
Bike was bought new in 1980 and in storage since 1981 in California.
I plan to race it in VMX over in oz.

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sandman768
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sandman768 2/16/2015 5:12am
2/16/2015 5:12am
mayzo wrote:
[img]https://p.vitalmx.com/photos/forums/2015/02/15/80378/s1200_image.jpg[/img] How timely is this thread to pop up. Picked this up on the weekend, it was for sale as a 79 but it's an 80...


How timely is this thread to pop up.
Picked this up on the weekend, it was for sale as a 79 but it's an 80.
It's all there, even have the factory handle bars that came on it that are strainght.
Original plastic, though faded.
Stock pipe and muffler.
Bike was bought new in 1980 and in storage since 1981 in California.
I plan to race it in VMX over in oz.
mayzo: nice find! you know its a low hr bike when the bars & kick stand are still on it! seat cover & rear fender are 79 items though? post some more photo"s!
BigAl
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BigAl 2/16/2015 7:15am
2/16/2015 7:15am
Started messing with my project. Got the 84 forks rebuilt with emulators, fox airs in the back. Gonna try to get the motor out his week and get the top end off. I cannot get the stem out of the 84 triples, missing airbox and both side panel supports are broken off. Joy.
wolfy0067
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wolfy0067 2/16/2015 7:38am
2/16/2015 7:38am
mayzo wrote:
[img]https://p.vitalmx.com/photos/forums/2015/02/15/80378/s1200_image.jpg[/img] How timely is this thread to pop up. Picked this up on the weekend, it was for sale as a 79 but it's an 80...


How timely is this thread to pop up.
Picked this up on the weekend, it was for sale as a 79 but it's an 80.
It's all there, even have the factory handle bars that came on it that are strainght.
Original plastic, though faded.
Stock pipe and muffler.
Bike was bought new in 1980 and in storage since 1981 in California.
I plan to race it in VMX over in oz.
sandman768 wrote:
mayzo: nice find! you know its a low hr bike when the bars & kick stand are still on it! seat cover & rear fender are...
mayzo: nice find! you know its a low hr bike when the bars & kick stand are still on it! seat cover & rear fender are 79 items though? post some more photo"s!
From the looks of the seat and plastic looks like a 79 VIN will tell the truth, think the 11th digit will read N for 79 or T for 80 model year, x for 81 z 82 d 83,e 84,f 85 and so on
mayzo
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mayzo 2/16/2015 12:20pm
2/16/2015 12:20pm Edited Date/Time 2/16/2015 12:25pm
mayzo wrote:
[img]https://p.vitalmx.com/photos/forums/2015/02/15/80378/s1200_image.jpg[/img] How timely is this thread to pop up. Picked this up on the weekend, it was for sale as a 79 but it's an 80...


How timely is this thread to pop up.
Picked this up on the weekend, it was for sale as a 79 but it's an 80.
It's all there, even have the factory handle bars that came on it that are strainght.
Original plastic, though faded.
Stock pipe and muffler.
Bike was bought new in 1980 and in storage since 1981 in California.
I plan to race it in VMX over in oz.
sandman768 wrote:
mayzo: nice find! you know its a low hr bike when the bars & kick stand are still on it! seat cover & rear fender are...
mayzo: nice find! you know its a low hr bike when the bars & kick stand are still on it! seat cover & rear fender are 79 items though? post some more photo"s!
Yeah the guy I bought it off thought it was a 79 until he gave me the old plastics and bars.
I'll post up more photos when I'm stripping it down to check over..
The front and rear guards have a betray and fox logo in them..
Is that normal or just a USA thing, don't remember my mates 125T having that.
Build plate says 11/79 also
Off-road sticker on R/h fork leg says 1980 California, $3.00.
wolfy0067
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wolfy0067 2/16/2015 1:04pm
2/16/2015 1:04pm
11/79 is an 80 model year. Look for the t on the frame stamp
mayzo
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mayzo 2/17/2015 2:08am
2/17/2015 2:08am
sandman768 wrote:
[img]https://p.vitalmx.com/photos/forums/2015/02/13/80150/s1200_image.jpg[/img] had bunch of hardware replated, replaced all the 35 yr old nuts with new. [img]https://p.vitalmx.com/photos/forums/2015/02/13/80151/s1200_image.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/02/13/80152/s1200_image.jpg[/img] replaced bogus suzuki silencer hanger with aluminum hanger off...

had bunch of hardware replated, replaced all the 35 yr old nuts with new.



replaced bogus suzuki silencer hanger with aluminum hanger off a 9o"s cr honda


rear rim & brake plate off an 81 or 82 rm 465, bolted right on, chain adjusters, axle, brake parts all replated, new chain adjuster bolts & nuts, new rear wheel bearings, found out axle is slightly bent, I will try my 84 rm axle to see if it fits, the 79 with the nuts on each end is weak.
Where did you get the footpegs?
sandman768
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sandman768 2/17/2015 6:01am
2/17/2015 6:01am
mayzo: pegs came on the bike when I purchased it, they look like early 90"s honda pegs, but not sure. I know DC plastics sells PRF pegs that are nicer & wider than mine for about 100$, I think you can also use newer oem RM pegs, pins & springs,say early/mid 90"s, & drill out pin holes, fit right on, did that on my 88 rm 250. good idea to drill out & use larger diameter pins, as the stock pins back then bend very easy. ....looking at your swingarm chain buffer & rear guide plate, they are 1980 items. 79 had roller on top of swingarm & spring loaded rear guide, both problematic...
wolfy0067
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wolfy0067 2/17/2015 7:49am
2/17/2015 7:49am Edited Date/Time 2/17/2015 4:02pm
sandman768 wrote:
mayzo: pegs came on the bike when I purchased it, they look like early 90"s honda pegs, but not sure. I know DC plastics sells PRF...
mayzo: pegs came on the bike when I purchased it, they look like early 90"s honda pegs, but not sure. I know DC plastics sells PRF pegs that are nicer & wider than mine for about 100$, I think you can also use newer oem RM pegs, pins & springs,say early/mid 90"s, & drill out pin holes, fit right on, did that on my 88 rm 250. good idea to drill out & use larger diameter pins, as the stock pins back then bend very easy. ....looking at your swingarm chain buffer & rear guide plate, they are 1980 items. 79 had roller on top of swingarm & spring loaded rear guide, both problematic...
Look at the KFX 250 foot pegs beleive 2004 was the year I used had to modify and drill pins the shifter need to be lengthened but is nice setup can be found cheap on ebay
mayzo
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mayzo 2/20/2015 9:14pm
2/20/2015 9:14pm






Original pipe and muffler, has been repainted but is dent free.










Betray and fox logo in the original front and rear guards. Is this a USA thing or was it worldwide at the time.
.

Original front brake lever and cable. Not loose and floppy.



Turns out its a 1980 T model not a 79. The guy I bought it off thought it was an 79N
and advertised it as one. My gain.
sandman768
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sandman768 2/21/2015 6:13am
2/21/2015 6:13am
nice! "Belray& Fox" were period correct decals from that era, Belray being oil company & you know who Moto x Fox is right? original shocks, they did not last long on most bikes, due to fading & I beleive non rebuildable. counter shaft sprocket guard & non damaged case is rare, for some reason thrown chains took these out with alarming regularity, maybe everyone thought chains last forever back then, I know I did! does anyone know what changes were from 79 to 80 model? I know on the 125 they went backwards with mellowing the engine out. What are your plans for this fine example?
mayzo
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mayzo 2/21/2015 6:33am
2/21/2015 6:33am
Plan to ride it in local VMX races. Heaven VMX club in Down here in NSW are getting one of Sydney's best tracks from the 70's/80's back up and running. Getting forks done and replacing the shocks with something newer. Swapping the pipe muffler over and racing it for a few years and then retire it to the shed.



Dargle MX 1980.
sandman768
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sandman768 2/21/2015 7:50am
2/21/2015 7:50am
track looks awesome! just think 125 when you ride it....thats how it needs to be ridden! Fox shocks were cool & period correct, but you can do much better with modern spring shocks, works performance, ohlins ect. I ride mine a few times a year, but it took me long time to find tranny gears when I rebuilt it, not doing that again. mostly garage queen, but I can look at it all day long!
edgo897
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edgo897 3/20/2015 5:45am
3/20/2015 5:45am
I ported my cylinder according to the MXA article. We dropped the intake 4mm. It seemed to increase the midrange a bit and it can overrev more.
wolfy0067
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wolfy0067 5/18/2015 1:14pm
5/18/2015 1:14pm
i was inspired to tear my recently purchased RM250 apart and do cylinder porting have

Pit Row

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Steve125
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Steve125 10/12/2015 6:12am
10/12/2015 6:12am
Hey guys, nice builds! Glad to say I'm finally getting to my 79 after buying it 2+ years ago and it sitting collecting dust while I built a few Hotrods..
The bike was a $300 CL special that had very little time on it. Crank is very good and top end is a relatively fresh 0.5 mm overbore. Trans wouldn't go into 1st but I found the shift shaft was on the wrong cog behind the clutch basket, and the shaft was bottoming out on the cases keeping it from going into first.. Easy fix.
Bought a ton of parts last week and she's starting to go together. Just have to do a little welding on the frame where the airbox mounting tabs are (were), and one rear side cover tab is broken off so I'll have to fabricate a new one to mount the number plate.. I'm looking for a silencer if anyone has one. The one pictured is incorrect. Looks like it's for an 84-85 and it is too big around the stinger end. Might just make a sleeve if I can't find the right one.









wolfy0067
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wolfy0067 10/12/2015 7:07am
10/12/2015 7:07am

Yep, same silence I used cut the spigot off, rewelded correct size and length, took 10mm out of the midsection of my chamber

.





Steve125
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Steve125 10/13/2015 6:08pm
10/13/2015 6:08pm
wolfy0067 wrote:
Yep, same silence I used cut the spigot off, rewelded correct size and length, took 10mm out of the midsection of my chamber .[img]https://p.vitalmx.com/photos/forums/2015/10/12/107778/s1200_rm_2501.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/10/12/107779/s1200_rm_2501.jpg_2.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/10/12/107780/s1200_rm_2501.jpg_3.jpg[/img]

Yep, same silence I used cut the spigot off, rewelded correct size and length, took 10mm out of the midsection of my chamber

.





Thanks for the info. I have an 81 125 silencer that looks like the stock 79 250 one, but it has the opposite problem, too small at the core / stinger. Might stick with mine and do mods like you did.
MaxPower
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MaxPower 10/14/2015 4:15pm
10/14/2015 4:15pm Edited Date/Time 10/14/2015 4:23pm
I like the 77 tank Wolfy. Was it difficult to mount?

If I get a vintage 250 anything I'd like to fit a sleeker 125 tank. Small tanks look better to me and not necessary if I'm not running 45 minute motos.
Get rid of those cheesy zips holding the carb on Mayzo. I don't know the name of them but I know where to get nice thin hose clamps that don't look like they belong on the radiator of a V8 Chevy. I'll send you a couple. Your bike look really fresh. 79/80 foot pegs always looked sturdy to me
wolfy0067
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wolfy0067 10/15/2015 4:52am
10/15/2015 4:52am
Tank was real easy to mt. just purchase two rubber grommets, weld two mt's and cover with grommets. I had a frame laying around and used the post setup from it.

Yep the thin hose clamps are the way to go, no zip ties on my engine, foot pegs are modified KFX250 with over size pins. tossed the chain tensioner and guide setup went with modified Pri Drive setup.
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captmoto 10/16/2015 10:25am
10/16/2015 10:25am
wolfy0067 wrote:
Tank was real easy to mt. just purchase two rubber grommets, weld two mt's and cover with grommets. I had a frame laying around and used...
Tank was real easy to mt. just purchase two rubber grommets, weld two mt's and cover with grommets. I had a frame laying around and used the post setup from it.

Yep the thin hose clamps are the way to go, no zip ties on my engine, foot pegs are modified KFX250 with over size pins. tossed the chain tensioner and guide setup went with modified Pri Drive setup.
Can you show some close ups of your chain guide? Some details of it? The trick back then was to cut 1" out of the belly of the pipe according to MXA back in the day.
MaxPower
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MaxPower 10/16/2015 11:31am
10/16/2015 11:31am
wolfy0067 wrote:
Tank was real easy to mt. just purchase two rubber grommets, weld two mt's and cover with grommets. I had a frame laying around and used...
Tank was real easy to mt. just purchase two rubber grommets, weld two mt's and cover with grommets. I had a frame laying around and used the post setup from it.

Yep the thin hose clamps are the way to go, no zip ties on my engine, foot pegs are modified KFX250 with over size pins. tossed the chain tensioner and guide setup went with modified Pri Drive setup.
You build some pretty trick bikes Wolfy. Sorry, I wrote my post to be confusing. I was referring to Mayzos bike with the thin hose clamps. His bike is way too clean to have fat white zips holding the carb on.
I remember my 79 125 would split the intake manifolds until the released the updated piece. A butch fix was to use a piece of radiator hose in its place.
Did you get rid of your Hondas? Did you ride the RM at Unadilla? If you did I'm surprised I missed it. A bike like yours would normally stand right out to me
wolfy0067
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wolfy0067 10/16/2015 2:05pm
10/16/2015 2:05pm
Made the guide from parts laying around. Pro drive kit from 08 Honda roller from pro tech kit had for years ran Unadilla on my 83 Honda 250 won 50 expert. Had a nice battle with Leichein in40 he pulled on me finial lap 500 kawi was strong on the up hills. Battle with Dowd and Stratton in Sportsman 250 won the overall. Lead the second moto most of the way. On U tube
Let me know if u need more pictures this bike is for sale.




captmoto
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captmoto 10/17/2015 10:51pm
10/17/2015 10:51pm
What did you do for the porting?
wolfy0067
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wolfy0067 10/18/2015 6:17am
10/18/2015 6:17am
Lowered the intake 3mm look at the photos, you can my scribe lines. Set the piston in the bore and scribed it also to see when exactly the exhaust port opened and that gave me my max to lower the intake and wide 2mm on each intake window.

Transfer ports where smoothed and matched to cylinder
Exhaust had some issues, matched the ports who've wides and raised .5mm went very conservative this area

Get some layout dye and. Be real conservative. Head was skimmed to assure it was flat surface, did a few tricks to the crankshaft also. Still playing with a flat carb, that's more to do with the air box side
wolfy0067
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wolfy0067 10/18/2015 6:21am
10/18/2015 6:21am


Here's my cab mount,no zip ties here

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