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Author Topic: PROJECT: 1979 RM125  (Read 18225 times)

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Offline motoxr377

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PROJECT: 1979 RM125
« on: July 10, 2012, 03:54:32 AM »
Hey guys-
Got another project on the way, this one's a doozie. It's a 1979 RM125, in terrible shape. I got it for a case of beer, and have been buying parts for it ever since. This bike's a clean canvas, so I might as well go all out. I'm building it in preparation for an assault on Unadilla MX Rewind 2013.

I'll post pictures as they roll in, but don't have much to show yet. Aside from new bearings, bushings, gaskets, and seals, here's the skinny on what I'll be making here.

DG Head - purchased
55.5mm Wiseco Kit - purchased
Pro-X Rod Kit - purchased
Vintage Iron Retro Rocket Pipe - being constructed
Custom Carbon Silencer - needs mocking up
Boyesen Reeds - on order
Pro Form Racing Footpegs - purchased
New brakes, cables, kill switch, throttle, levers/perches, kickstarter - purchased
Renthal Vintage Hi 7/8" bars - purchased

Cylinder, DG Head, Piston Kit, and Reed Block are off to Eric Gorr right now to be bored, honed, milled, and ported for a Mid-to-Top powerband. The magnesium clutch and ignition covers are off to PTI industries for a Dow 7 treatment. Later in the build I'll focus on the suspension, sending the forks off to Race Tech and have custom Shocks built to match. Stay tuned.


« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline TMKIWI

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PROJECT: 1979 RM125
« Reply #1 on: July 10, 2012, 10:29:11 AM »
Sweet. Look forward to seeing the progress.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
If you don't fall off you are not going hard enough

Offline SachsGS

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PROJECT: 1979 RM125
« Reply #2 on: July 12, 2012, 05:02:51 AM »
Some piggy back Ohlins would be trick. ;D
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline twosmoke595

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PROJECT: 1979 RM125
« Reply #3 on: July 12, 2012, 04:48:16 PM »
Some piggy back Ohlins would be trick. ;D

only kind of shocks that need to be on a vintage bike are the fox floaters. but then again they're impossible to find, but if you can find them, fox shocks are the way to go. But if you cant then ohlins should be pretty good too  ;D
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline motoxr377

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PROJECT: 1979 RM125
« Reply #4 on: July 12, 2012, 05:27:04 PM »
Sweet. Look forward to seeing the progress.

Thanks. I am trying to gauge interest, if nobody cares I don't think I'll put in much effort posting.

Some piggy back Ohlins would be trick. ;D

I feel the same way. Race Tech's with remote resevoirs are a good deal and fully custom per application. I can get them anodized gold as well  ;)

only kind of shocks that need to be on a vintage bike are the fox floaters. but then again they're impossible to find, but if you can find them, fox shocks are the way to go. But if you cant then ohlins should be pretty good too  ;D

I plan on this bike being legal for SEVMX series (just moved to Georgia). I don't fall under the more stringent AHRMA rules (except when I go to Unadilla), so I'm making the suspension as modern as possible, within reason.

Here are some photos.
I am replacing all factory hardware (especially dreaded phillips head bolts) with Flanged 8mm or Allen heads. The fuel tank cleaned up well, but far from show quality. I'm riding it though, so it's all good.


The DG Head and Cylinder, cleaned up before getting shipped to Eric Gorr.

Here's a shot of the Clutch cover mid-blast, before getting shipped to PTI.


Enjoy, more to follow! I just got a VM34 from Sudco with their baseline jetting, pretty exciting stuff.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline TMKIWI

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PROJECT: 1979 RM125
« Reply #5 on: July 12, 2012, 10:38:19 PM »
DC Plastics do complete Allen head engine bolt kits for a reasonable price.
I replaced all the engine bolts on my 84' and it looks good.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
If you don't fall off you are not going hard enough

Offline riffraff

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PROJECT: 1979 RM125
« Reply #6 on: July 13, 2012, 04:46:06 AM »
That DG head is beautiful, I always liked the gold anodize 
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
aaahhhhh yes, I remember the good old days

Offline SachsGS

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PROJECT: 1979 RM125
« Reply #7 on: July 13, 2012, 03:11:45 PM »
Did that model of RM have a combination of piston port/case reed induction? I always wondered what Suzuki's reasoning was behind that setup.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline citabjockey

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PROJECT: 1979 RM125
« Reply #8 on: July 13, 2012, 09:15:12 PM »
My '78 of the day had a 2 petal reed in the floor of the intake port leading direct to the crank case. It made a good spread of power. I think the 79 has the same setup despite being a new motor (the original poster can confirm). I believe the theory was to have a unblocked intake port for when the timing is a perfect rpms and have the reed valve so the crank can suck before the piston opens the port. Seemed like a good idea to me but I guess very large reed cages arranged for pretty much the same result.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
Yamaha CT3, RT3, MX125, SC500, Toy Prius, Diesel F250 (it all balances out)

Offline motoxr377

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PROJECT: 1979 RM125
« Reply #9 on: July 13, 2012, 10:36:59 PM »
DC Plastics do complete Allen head engine bolt kits for a reasonable price.
I replaced all the engine bolts on my 84' and it looks good.

Already in my possession! Nice piece of kit.

That DG head is beautiful, I always liked the gold anodize 

Thanks man. It's pretty rough, so I might need to polish it and re-anodize it again.

Did that model of RM have a combination of piston port/case reed induction? I always wondered what Suzuki's reasoning was behind that setup.
My '78 of the day had a 2 petal reed in the floor of the intake port leading direct to the crank case. It made a good spread of power. I think the 79 has the same setup despite being a new motor (the original poster can confirm). I believe the theory was to have a unblocked intake port for when the timing is a perfect rpms and have the reed valve so the crank can suck before the piston opens the port. Seemed like a good idea to me but I guess very large reed cages arranged for pretty much the same result.

Yep, two-petal trap-door reed block in the crankcase on the base of the cylinder.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline motoxr377

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PROJECT: 1979 RM125
« Reply #10 on: August 01, 2012, 04:22:33 AM »
Just talked to Eric Gorr, he's getting to it this week. Excited!!
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline SachsGS

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PROJECT: 1979 RM125
« Reply #11 on: August 01, 2012, 03:30:01 PM »
Has anyone tried Falcon shocks?
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Coop

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PROJECT: 1979 RM125
« Reply #12 on: August 01, 2012, 08:12:03 PM »
Good luck man, looking forward to seeing it as you put it all back together.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
- Mike - Don't take life so seriously, nobody gets out alive.

Offline MXLord327

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PROJECT: 1979 RM125
« Reply #13 on: August 02, 2012, 02:42:51 PM »
I always loved RM125's, started on a '78, moved to an '81, '83, and '84.  Never had a '79 but they were one of the best looking years for the RM, great choice for the project!
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Coop

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PROJECT: 1979 RM125
« Reply #14 on: August 19, 2012, 08:54:19 PM »
Updates?
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
- Mike - Don't take life so seriously, nobody gets out alive.