1984 kx125 my new project

Pictures man, pictures!!!

I know, right?!? What a tease to no post any pics!

Cool - it looks salvageable.
The motor's on those things were pretty solid.
The frame - not so much. Look for cracks, especially around the steering head area. In 85' they added some gusseting around the lower portion of the steering head to stop this from happening.

At the moment I'm rebuilding a 84 motor as a 2nd motor for my 83.
Check or replace every bearing in the cases. The 84 had a worn clutch shaft bearing . (The shaft opposite the counter shaft) I've never had an engine have that bearing so worn. Lap the cases because old Kawis suck for air leaks. Use 83 Yz125 stator side main seals ( a extremely helpful Vital member turned me on to that tip) You are going to want to have the ports matched. They have the worst castings I've ever seen. Don't over tighten the reed block. You get an air leak. Your frame is going to crack. Sand blast it, check for any existing cracks. Add gussets on every area that looks cheesy. MX Rose already mentioned the steering head. I've seen them crack near the swing arm pivot. Early shocks weren't hardened. You may want to check if the shock body bore is worn. Not saying you have to ,just telling you they did wear. The coolest part of the 84 was the front fender brace you don't have. I'm having one shipped. I'll trace it and send you the pattern if you like to make one. The spoke nipples are aluminum. You may be getting née spokes if they are frozen. Electro fusion coatings sucked new . Its possible you will need a replate. Seal the crap out of the exhaust flange to pipe with hi temp silicone. It's going to leak. Kawasakis leaked air going in and coming out.
I may have that chain guide for you. I bought it but used something else
It sounds like a lot . It is. You asked
I almost forgot. If you buy main bearings buy OEM. DONT get the Hot Rods Main bearing kit. They have the wrong size bearing in the package. When you call them and tell them to get a new one, They tell you its not their fault and you will have to buy the correct size from them, True story.Not to mention you have to wait to finish installing your crank until the correct part arrives

Nice work -the 84-85 kx 125"s are legendary bikes.I am a suzuki man normally but I couldn't help myself and brought this old girl which has a fresh engine but very ugly comestically.Its a 1985

I would love to find a decent 85, very fond memories of that bike. Good luck on the 84 resto...I remember one of the magazines testing it, and after repeated "sky shots", the frame broke, so follow the advice, inspect/gusset.

Not to change the topic, but about the YZ. Are those original graphics from back then or did you have those made somewhere? I wanted to build my old 125 from back then with those same graphics.

Remember that bike well. Bought as a year holdover in January 17, 1985, in Stafford, Texas.

I have seen muffler burned tanks on 80s KX and KDX. Check for burn marks on the bottom of the gas tank in the area over the muffler. As parts and frames get tweaked in crashes its not uncommon for the muffler to come in contact with the gas tank. Self adhesive thermal insulation on the tank is a good idea in this area. Good luck with the project.

Frames on all used bikes should be gone over carefully, you never know the history, it may have been a pro's practice bike and had many G-outs placed upon them!
Good luck with your build, parts can be tough to find on older kx's.

Nice. I will be following, I just got one today. I will be having my ports polished and the Electrofusion Coating redone.

My 1984 Kawasaki KX125:
https://p.vitalmx.com/photos/users/25684/photos/89478/s1600_1984_Kawasa…

So I finally found one here for $250 last night. she's rough but runs good. I already have it stripped down to the frame. rear section was bent. I think I got it straightened out though. The bad thing is that it has an 83 shock. I am looking for a 84 or 85 replacement although there is very little difference except the reservoir.

I am going to get the frame blasted and powder coated. all new bearings etc.
I had one of these bikes back in the day and was even lucky enough to race it at the last year of the world mini 1984 at saddleback against Bader Manneh lol he smoked us.

Pretty pumped on this winter project that I dont have time or money for!

Not my bike, I just noticed it and thought of this thread:
http://seattle.craigslist.org/sno/mcy/5884347715.html

Looks to be an 84 or 85.

It's an 85. First year for the power valve
I remember someone here had a tough time finding worn powervalve parts

Yeah I was eyeballing that one and texted the guy. You can see the power valve and silver frame.

I raced 83, an then 85 kx125s back when they Where new. They both broke frames. Steering head on the 85! All the problems noted by others are true. Hardware sucked too. There not many left because they where not built to last. BUT they where hands down horsepower king. Good luck and nice to see it saved.

I totally agree with this. I tighten the fasteners on my bike as if im working on a model airplane.
I tried to get ahead of the curve by adding gussets to a fresh frame.
I used to ride so much as a youngin thst id have a stsck of worn sprockets by the end of the season. My KX should stsy tight as i haven't ridden it enough to adjust the chsin 3 times in the past 2 years

Hey all,
I wanted to see how this project came along as I am picking up an '84 pre KIPS KX 125 this week. Looking for some OEM parts to restore it eventually after riding it around this fall/winter first. I'll check the frame out for sure as I'm one of those big kids who makes every motorcycle look small. Hope to hear more from the OP, and have a great weekend all.

Anyone know if this disc boot is OEM or aftermarket?



Front brake master looks like a replacement, handlebars and bar bumper as well look aftermarket.



Rear mono shock definitely needs a recharge, maybe teardown.

Absolutely Tom Morgan Racing over Eric Gorr for any Kawasaki build... TMR was the OG builder on Factory Kawasaki bikes and has forgot more than Eric ever learned about a KX125 motor... Did all the porting/ head work on our 125 and the bike just rips 😉!