[hoboscratch]

Hi all. New to the forum, to dirt bikes, and really to owning motorcycles. I've ridden friends and my dad's bikes before but never got around to buying one. Well, a buddy of mine got laid off and got a job out of state. Long story short, he gave me his 1985 kx125 for $0. He said that he bought it about 2 years ago and thought that it started, but for some reason wouldn't move. He couldn't remember what the problem was. He never got around to messing with it.

I'm pretty mechanically inclined although I don't do it for a living. I do all my own work on my vehicles but generally its brakes, pumps or sensors, suspension, and the like. Usually not engine type work but I have access to people who are skilled in such things. So I think I have the skills, resources, and tools to tackle most things.

However, being new to small engines I am not 100% sure where to start on this. I have a serivce manual on order from ebay (the OEM, not the Clymer) and was planning on first doing a compression test. Assuming that is ok, I was then going to take off the carb and give it a good cleaning, drain any fluids and replace, as well as replace any filters. Then check for spark and try to start it.

Does this sound like a good start?

I know right now that I'm going to have to replace the brakes, change shock fluid (or replace), tires, and have the spokes checked to make sure they're good. I don't know anything about the transmission or clutch.

 

[solitary]

Does it kick over? Don't actually try to start it, just see if the piston moves.
If no, can you put it in gear, perhaps second or third and push it?
If not, get back to me.
If so, start off looking in the carb, clean it really good. Clean the air filter. (buy a Uni-foam air filter cleaning kit) Before you do anything else. You have no idea what kind of crud and citters will get in the intake.

Now, try to start it. If it runs, great. If not, check the spark plug and compression.
Then get back to us if you're still having issues.

 

[hoboscratch]

Thanks for the reply, solitary. I could not get it to kick over. With it in 2nd and 3rd gear I could push it, and I could feel the gears catching.

Also, I now remember him saying it having issues with shifting, and under closer inspection, the shifter looks like it needs either simply tightened on the spindle that comes out of the tranny or outright replaced. It is not gripping on the spindle and I had to work with it to get it to shift. I will have to look at that closer and see where the true issue lies.

With it not being able to kick over, that sounds like a bad sign. At this point, is my next step to start taking the engine out and finding somewhere to take it for further inspection or are there more things I can do?

 

[hoboscratch]

Update: moving the bike in gear must have freed up the piston. I am able to get it to move. I took the carb off and then noticed the rubber manifold going to the motor was cracking, so I took that off too. There was a ton of dirt in the screened contraption (sorry, my manual isn't here yet...) that was behind that. Took that out and I can see the piston, it will move freely. So that's a huge relief. However, this bike has no airbox so I dont know what if anything was used as a filter. I have no idea how much dirt is in the engine itself.

Any further advice on how far to take it apart before trying to start it knowing what we know now?

 

[Polar_Bus]

Update: moving the bike in gear must have freed up the piston. I am able to get it to move. I took the carb off and then noticed the rubber manifold going to the motor was cracking, so I took that off too. There was a ton of dirt in the screened contraption (sorry, my manual isn't here yet...) that was behind that. Took that out and I can see the piston, it will move freely. So that's a huge relief. However, this bike has no airbox so I dont know what if anything was used as a filter. I have no idea how much dirt is in the engine itself.

Any further advice on how far to take it apart before trying to start it knowing what we know now?

At this point, reading your details, i'm guessing, if there was enough rust in the cyl (or crank) to sieze the engine, you probably should expect to perform a complete teardown and rebuild. At the very least perform a compression test, you should be around 140 psi. Keep un mind, virtually EVERY bike I have had experiences with that were "ridden hard and parked wet", and then sat for long periods of time not run, the engines are JUNK. Sorry to be so morbid, i'm juts trying to be honest. If you are looking for a project bike, then with some cash and patients, you can learn a lot....

 

[solitary]

I'm with Polar_Bus, before getting too monetarily involved. Clean the outside of the engine. If water cooled, drain the coolant (find the water pump, there's a bolt that looks out of place, remove it, coolant will drain). Not sure if the 85s were water cooled or not.
Remove the head, this is a handful of bolts on the top of the engine.
Remove the cylinder.
Have a look around.
See any rust? Bad sign.
See dirt? Bad sign.
Can you feel up/down play in the crank? Bad, bad sign.
Remove the piston from the small end of the rod. IMPORTANT! Don't attempt without removing the piston! Rotate the crank with the connecting rod, it should feel smooth. Any catching, notchiness, etc.? Bad Bad sign.

If there's more than one bad sign, or any "bad bad signs", the bike isn't worth rebuilding unless you can get your hands on a replacement motor that runs. If you want to learn something or there's sentimental value, that's a different story. This particular type of education will run you at least $200 for multiple "bad signs" and probably in the range of $500+ for any "bad bad sign". Which is why I would look for a replacement engine.

Word of warning, be very cautious about buying from motorcycle salvage yards. I got burned by Dave's USA to the tune of $240. So if you find one, it wouldn't hurt to ask around if anyone has had any bad experiences with that salvage yard. Private party? I personally have never had any problems this way, but of course, buyer beware.

 

[nd4speed]

dirt inside the reed cage? That doesn't sound good. 1985 anything is worht much except when sold piece by piece. Sounds like the whole thing needs to be torn apart. If it was a 250 it might be worth it if you could do most of the work yourself. I would try to sell the parts and when you get an offer take the part off and sell it. Use the money to buy a newer bike that runs.

 

[hoboscratch]

Thanks for the replies. Solitary, I am at the very least going to do what you mentioned for the learning experience if nothing else. I will report back what I find.

This help is exactly what I was looking for. Trying to determine how far (time and money wise) to go with this bike before determining its worth or non-worth.

As I said, I got this bike for free and there is no sentimental value whatsoever. If the engine looks like junk, I will look into parting out whatever is salvagable.

I will post pictures of the internals as well.

 

[650hardtail]

see if ya have spark..

 

[hoboscratch]

I didn't check to see if I had spark, I just started in on work after dinner w/o checking this thread. Here is what I found:
Picasa Web Albums - aaron - Kawasaki

So there is some rust in here. To the following questions:
Remove the cylinder.
Have a look around.
See any rust? Bad sign. Yes
See dirt? Bad sign. Yes
Can you feel up/down play in the crank? Bad, bad sign. No
Remove the piston from the small end of the rod. IMPORTANT! Don't attempt without removing the piston! Rotate the crank with the connecting rod, it should feel smooth. Any catching, notchiness, etc.? Bad Bad sign. No

I might add that there are no gouges in the piston or in the cylinder...

So I believe there is also water in the oil pan. I didn't drain it but you can see in pics 11 and 12 water beading on the crank. Also I dont have a pic of it but as I moved the crack w/ the connecting rod, when I got to the side that was sitting in the bottom, there was a rusty colored sludge on it. It wiped off but there's still junk in the pan.

My boss used to race when he was younger and has experience on these sorts of things, so I'm going to take the top end into him to see what he suggests, then maybe take it to a shop and see what the damage might be.

However, with the crank moving smoothly, am I potentially good there? Or will the rusty sludge and water in the pan pretty much mean that its f'd? Thanks so much for the help!

 

[KDXGarage]

Part it out for what you can and be done with it. If you are looking to get into dirt biking,t this bike IS NOT the one for you. If you are looking at wasting a lot of time and money on a 25 year old bike, then this is the PERFECT money pit for you.

 

[nd4speed]

or find a cheap running one that is the same year and use that one for parts. Easier just to sell the parts and move on 2 a better 250cc bike.

 

[hoboscratch]

Yeah I'm starting to think the same thing. I haven't put a dime into yet, just a couple evenings worth of work. Looks like this thing was not maintained at all and treated quite poorly.

 

[KDXGarage]

Is IS valuable to someone, but I would imagine that you do not have a warm spot in your heart from 25 years ago when you had the exact same model. There IS someone out there who does. He or she may need parts.

 

[Revis]

KDXgarage is right. I have an 82 that I keep fixing up and fixing up because I want to ride more and it's so hard to find the right parts. Everything is just so outdated in it that nothing holds up right. I do rig some things on it but where one things fixed another thing breaks. I'm about to part it out and try to buy a newer year. Only I can't find a kawasaki 125 for under $1000. If your looking for money, part it. If your looking for something to ride. See what you can do for the cheapest amount of money to ride it. Or part it and buy something newer.

On a different note, you will most likely need a new piston, and your cylinder bored. As for the bottom end, I haven't seen it so I don't know what you would need. Good luck