1989 CR125, lots of issues, new to me.

Hello all. Just got a 1989 CR125.

Current problems:
Runs like &*%(, seems to be running really rich, plug chop tomorrow, and a thorough cleaning.
Caliper is siezed, pads are shot, master cylinder screws on top are rusted to crap and stripped.

I got a couple questions on parts interchange.

If I wanted to go with an aluminum frame, what are my options? What years can I do?
What year front brakes work on this thing?
What years plastic could I use. In other words, how do I get newer style plastics on this bike, or is that not possible?
What sprocket combination should I look for, or is stock just fine for everyone out there?
If the motor goes, could I fit a newer style 125 motor in this frame? Like an 05 motor in the 89 frame. Possible?

How much horsepower difference is there between a 2003 CR 125 stock, and mine with FMF exhaust and carbon fiber reeds? What if I port and polish it? Is there someone I could talk to about some porting specs?

If anyone could point me to informative websites they know about, I'd greatly appreciate it.

Thanks for looking!  

Welcome, I am not going to be much help.   If you want a newer bike try parting it out for a little profit.  
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"Every time I start thinking the world is all bad, then I start seeing some people out there having fun on motorcycles. It makes me take another look." -Steve McQueen

http://www.cmsnl.com/honda-cr125_model216/
try looking through the different years and match the part numbers  

Where to start?
If you wanted to go with an aluminum frame just get the whole bike and sell the '89. As far as the motor goes.. I would take the '89 over the '05.
The plastic that's on the bike is about it unless you change color.
I know the a LOT of parts are interchangeable with the '88 CR125 and the 89 250.
Anything else let us know.
Greg  

Good to hear you have confidence in the older engines. Reasons for choosing the 89 over an 03+ engine?

Where should I go to look for black plastic? Or any other colored plastics? This thing also needs a full bolt kit really really bad...

The front caliper cand move around a little on the mounting bracket... The actual black caliper part can scoot around a little bit on the bottom (going clockwise, it's the last) pin thing. Looks like there should be a rubber grommet or bushing around that pin, and it's not there, so the caliper can move around a quarter inch or so.

Where's the cheapest place to get brake pads.

Another thing. On that carb, I will be cleaning it out tomorrow, so we'll see if it's just a clogged vent hose or air passage or something, but here's its problem. It's currently idling high, smoking quite a bit, has no power whatsoever in midrange or idle, and bogs at 1/2 to full throttle. This bike will NOT even think about pulling the front wheel off the ground right now.

I also found out I have an exhaust leak up front. I'm not a Honda guy, so could anyone tell me what the heck is that box thing up by the exhaust pipe? Smoke and oil is coming out from around there. Also, there's nothing connecting the pipe and the silencer except a little screw going into both tubes. Shouldn't there be something that slips over both ends and clamps down on each? I noticed that there is a little oil coming out from where that pipe/silencer meeting is, could this be a right crank seal going out, or is it just running THAT rich?

Pulled a plug chop at half and full throttle, both showed a wet near-fouled plug.

Let me know your thoughts.

-Travis  

Try either bike bandit. com for OEM parts.

motosport.com is also a good place for aftermarket parts. Pretty sure you'll find your black plastics or any other color there.  
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That thing must run like a raped ape. But has anyone ever seen a raped ape run?

The '89 was really fast, but only when revved to the moon. It will never have much bottom or mid power. Not even if you get everything fixed.
The box on the front of the cylinder is the ATAC chamber. It fools the engine into thinking it have a variable length header pipe. It worked well, but not as well as the later 90-97 power valve engines. After '87 the CR engines got slow, or actually they stayed the same and everything else got fast.
You have too much money to spend just getting that bike safe. Don't worry about frames and plastic. You can't get graphics for it anyway.
If the motor goes, rebuild it if it isn't major, or start with a different bike.
The calpers should move a little side to side, but shouldn't rock back and forth. Get that fixed. You may need the caliper mounts and pins as well as the rubber seals.
A garage "port and polish" will make it worse. Just make sure it is running right.
The high idle could be an air leak, and you will need to find that. It could be crank seals on both sides.
Before you get too far into the project, make sure it is worth it. That bike in perfect condition is worth $1500 max. If you ride it for any length of time you are all but sure to need a crankshaft, seals, bearing and a piston if you are lucky enough to have a good cylinder. Add another $200 for cylinder plating. And you still haven't fixed the brakes or rusty parts. For sure the suspension will need serviced and the shock bumper replaced. If you want a project to help you learn, go for it. If you are looking for a bargain ride, this may not be it. Don't forget to check the swingarm and linkage bearings. I went through a 1989 Kawasaki KX250 a few months ago. I had to do nothing to the engine, and I had over $1000 in parts to get it safe, and that bike had been raced right up until it was parked.  

ok i have a 89 cr 125 and i see that yours has some problems. ok first i just rebuilt my bike this week with a new piston, rings and gaskets for the top end and that was about $150 and it's fast!!! no lie.
on the exhaust i have the same problem um you in a metal sealer ring where the expansion chamber as the springs and goes on the jug or cylinder and its liveable for me because it's only when i just start it up and let it idle it leaks but you never notice it when riding and to conect to silencer i used and piece of black flexable tube with clamps on both sides and that work great. and the black box is call the exhaust joint and i don't know what it does but it's a chamber i cleaned it before i put my bike back together. With the plugs i've noticed that if you didn't rebuild the top end the plug foul like crazy and if this happens a lot what i did was crank the crap out of it with full throtle and if it doesn't start take the plug out wipe it off and take a lighter to it so it dries it and hurry and put it back in after you do this and don't choke it or give it any gas and see if it starts if not you have it bad. and it sounds like you need a new ring and piston. that will change you bike so much it unbelievable how much more power you have.  

I have an 89 I'm parting out, just kept the engine for a kart. Good parts, cheap prices, money back guarantee.

I'm not known here but on other forums I am, as well as ebay. drop me a PM if you want anything in particular.