Hey all,
I'm new to the forum, and new to riding. Please help the new girl if you can

So i just got my first bike, a 1989 kx125. It's in good shape as far as I can tell, but I noticed it wouldn't idle.
I tried the screw, but it was no help, so I adjsuted the throttle cable adjuster and i got it to idle, yet its still a low idle.
I was thinking about adjusting the jet needle, depending if im running rich or lean ( i can't tell yet) I figure if i adjust thatup or down and it would help my idle.
Am I on the right track? It's just me, my boyfriend ( who is learning too) and my manual trying to figure this out.. so any help you can give is great.

Also, I need to replace my right handlebar. That could be messing with my throttle connection.. loose cable? not sure, but there is a crack in it right where the throttle cable goes into the handle bar. Appearantly the last owner tried to glue it back together, but its not holding anymore. Any tips on replacing it?

Thanks in advance!

 

Hello Lyn, welcome to the forums!!
Congrats on your ride. Make sure you gear up on that thing..

Prob the first place I would start, is the plug..is it burning the right color? Does it have the right gap? Does it look fuel fouled? Does the bike run good except at idle?

Is there not an idle speed adjustment on that new baby of yours?

If i remember right on that bike, it has a double float in one bowl, and there was a prob with the needle sticking a little. So, maybe a real good carb cleaning...Maybe a fuel filter?

If you can give us just a bit more info on how she runs through the gears and at varied RPM it will help a little..Not much help I am!! lol

Enjoy your stay!!

 

I didn't check my plugs yet... I will in the morning, and let you know what I find.

I ended up replacing the handle bar today, no problem with the throttle cable.
There IS an idle adjuster.. the screw i mentioned in my earlier post... sorry I meant to be more descriptive.
I was able to adjust my jet neddle to run leaner, and also adjusted the idle screw all the way in. That got me a good idle.. temporarily. I moved my jet needle back into the center grove, adjusted the idle screw a bit more, still in a good deal, and took it for a ride.
I was alright for a minute, but then I kept stalling. I stalled about 10 times. I thought it was just me as a beginner, but my boyfriend tried it out and had problems too...
I'm not sure what the problem is. It didn't stall like this before. It ran great! Before It only stalled because I was learning, but this time I feel as though it's the bike and not me.

I'm only working in 1st gear (newbie with a small backyard) So i can't give too much info here.
I hope that gives more details. Any ideas are appreciated.

Thanks!

 

Once you get the plug pulled, it will tell you how the bike is running...lean, rich, hot, etc...

Sounds like a good carb cleaning and adjustment would prob take care of it. You said you adjusted the idle screw all the way in, so it sounds like the low side in the carbs is prob dirty, etc..I think those floats in there are those dual bronze metal ones, so when you get her tore apart, make sure one of the floats does not have a hole in it..

Let us know how that plug looks....

 

ALRIGHT!
It's been awhile, but here's my update...

So, I thought I had a good idle going now, got my jet needle right in the middle, it ran good last week, and I took a break since my left hand was in bad shape.

Yet this morning, I do a compression check. (good range by the way) Yet after pulling out the spark plug (cold) I found it was wet, and fouled! I think its oil/fuel. The gaps look good, yet its all black. I cleaned it up a bit, put it back and started her up.
My idle is ALL OVER THE PLACE. It started out way too high. It sounded like I was holding on the throttle, but I didnt even touch it. I let it warm it for about 5 minutes and the idle went from too high, to too low, to somewhat normal, to too high again. before I took off riding (5 minute mark) it was on the low side. I felt it 'buck'. In my opinion it's not handling low rpms well. Once it gets going through 2nd and third gears, and higher speeds, it feel more normal. Once it slows down again, it just doesn't feel right, its like the throttle kicks in on its own. And there is a more rapid 'putt putt' noise than before.

What should I do?
My air filter looks good. Because of the spark plug I'm assuming I'm running too rich. Should I move my jet neddle back toward the lean side? Should I replace my fluids? Or do you really think its necessary to clean through my carborator?

Any help is greatly appreciated.

 

Ya, you are running rich...from what it sounds like, it is time to go through the carb...[:@]

It's not too hard tho'......3-4 cans of Berryman, 2-3 six packs of Corona, 5-6 Rock CDs.....Print this list out and you will be good!! lol

I would go through the carb...That carb is dirty. GL to ya....

 

Thanks for the advise, I'll let you know how it goes.
I might have to substitute those Coronas for some mike hard lemonade, but it should work out nicely. LOL

 

just get a marker, paper, and some tape and you hve a mikes hard lemonade to corona convertor

before


after

 

ha ha ha ha!! Love that Converter....You should patent that man...Somebody else is going to come up with the idea, and you are going to be pissed it wasn't you making all the money on it!!!

LOL lol lol

 

That's a great idea! patent it before it's too late!

Just an update on my bike. I cleaned out the carb, didnt need much cleaning at all though. It was spotless! but i ran it through some carb cleaner anyways, let it dry out good, pieced it back together no problem...
But it didnt help. Well the idle is steady again, yet its at a steady LOW. so low, that when I go into 1st gear from neutral, it shuts off on me.
Next stop is a new spark plug.