1984 KTM 125 MC

[DKWRACER]

If anyone interested, I do have an 84/250 FS. Cleaned up pretty nice and MX version..

Adios, Tom Brosius

[brian kirby]

Just in case anyone needs a rod kit, I found one that will work. The 84-86 OEM rod from KTM superceeded to the '87-'97 part number. Pro-X has one listed for 89-97 and since the stock one superceeds to those years I took a chance and ordered one. The stock 84-86 rod is very narrow and not "H" shaped, this rod is an "H" beam shape and appears to be a little heavier than the 84-86 rod but all the other critical measurements, both pin sizes, big end width, length, are all the same.

I'll report how it works when I get everything buttoned back up.

Brian

'72 Berkshire

[Dennis Jones]

Brian, A while back I let Gary have 3 of these bikes. One nice runner, One pretty complete one that needed motor work, and one in a box. Which one did you end up with?

Dennis Jones

[brian kirby]

I got the "pretty complete one that needed motor work". The only thing it was missing really was the kickstarter which I snaked from Scott two days ago on eBay.

Gary and I talked about the bikes he had, that is the one that fit my budget and I dont mind a project. The Motoplat was bad, but I swapped on some known good parts and it actually started up quite easily, but had a monstrous rod knock. I took the engine apart and the big end bearing rollers were square and fused to the big end pin, it must have had 1/8" of radial play. The rest of the engine looks great, main bearings are tight, cylinder is good, even the piston is within spec. Once I get the engine back together all it needs beyond the normal cables and tires stuff is the WP shock need a rebuild. I'm really looking forward to riding this bike against the Japanese horde in MX.

Brian

'72 Berkshire

[evomx244]

Brian-
 Thanks for the Info, now instead of a rod kit costing around 255.00 I can pick one up for under a 100 bucks. what does your clutch cover look like ?  mine needs some work, but a little JB weld should do the trick.

[brian kirby]

The cover has the typical mag rot you see in all those bikes like the early 80s Honda CRs with the mag waterpump covers, but I have seen a lot worse. It can be fixed with some JB Weld, and my Dad has a small powder coating setup what I might coat the cover on the inside of those passages to keep it from rotting away more where I dont do the JB fix.

Brian

'72 Berkshire

[paul a. busick]

Hi Poggers,
 For your info. A neighbor of mine has a new KTM 1984 125 cyclinder and bottom end with crank rod and gears (no clutch or ignition).
 You can contact him via email - [email protected]
Merry Xmas& Happy New Year,
Paul

[evomx244]

Paul-Thanks for the Info, I just sent him an email
Scott

[evomx244]

125 project

[brian kirby]

Thats funny! That is exactly what mine looks like right now except mine is the MXC not the MX. I wanted the MXC because of the wide ratio transmission and MX tuned suspension. I notice yours still has the original front tire on it like mine does too.

Brian

'72 Berkshire

[brian kirby]

The Pro-X 89-97 rod went in perfectly. The engine wil go back together in a week or two, then the shock is going off to be rebuilt.

Brian

'72 Berkshire

[slvrbrdfxr]

Brian,
Is there an easy way to distinguish between the MX and MXC models by looking at the frame serial number or engine serial number ?? Thanks !
Dave McCullough

[brian kirby]

Dave,

The easy way to tell is the MX does not have a rear frame loop, and the MXC and EXC do. Also the MX has an internal rotor Motoplat with a smaller mag cover, the MXC and EXC both have an external rotor Motoplat. The MX right center case is actually different from the MXC/EXC because of the smaller mag cover. I dont know if you can tell by the serial numbers.

Brian

'72 Berkshire

[slvrbrdfxr]

Brian,
Thanks for the info. Hoping it will come in handy for a bike that my neighbor told me about recently. I'll let you know.
Dave McC

[evomx244]

I ended up buying the cylinder from Paul's neighbor. I bought a set of forks for 20 bucks as the ones on my 125 had some pitting going on. I also bought a 85 KTM 250 air filter cage off ebay for 5 bucks to replace the missing one on my 125. Just gathering up parts, I have a few bikes ahead of this one.