KX125 97 fRIGGIN JUNK! ergg...need help

[cnl83]

Ok, I bought a KX125 1997 model. I got this bogging problem, that I talked about in other post, but im going to sum this up. It boggs before the power band kicks in, in any gear. If im at idle and hammer the throttle quickly, it will BOGGG WANNN! If you hammer it on choke it doesnt seem to do it as much.
Things Ive done...

1) Dropped the jetting from 160-150-142 back to 160
2) Moved the needle to position 1-5 and back in the middle.
3) Cleaned the filter
4) Cleaned the Power Valve (not running though)
5) Messed with the air screw
6) Cleaned the jets, cleaned the carb
7) Changed the packing
8) Ran it without the silencer
9) Checked the choke
10) Changed the plug (Showed Tan) im no pro though
11) Changed my mixture to 40:1 (castro 927)
12) Checked the reeds and they are boyesen carbon fiber reeds...good shape.
13)Took it down about 40 times, and im almost in tears with frustration at the moment...

The power is not there, that is soppose to be there. Its bogging, and ticking me off bad! The cycle place I bought it from, says its a relatviely new top end...so I dont know, except go get a darn hammer. I would appreciate any help I could get. Thanks!

p.s. The power valve, should I have been able to move it back and forth with my fingers? Cause I couldnt move it.

 

[ellandoh]

i could move mine on every bike ive owned , mostly hondas and a couple yammies, not sure of the kawasakis but if i was a betting man...............

 

[QKENUF4U]

so see if it moves while you have the atuator cover off. if its just a plastic/rubber cover bolted to the side of the cylinder then it doesnt do anything but protect the arm etc.from rocks/dirt.
i had the same problem on a KX 125 at the shop i worked at.
i pulled that cover, started it, reved it a few times, NO MOVEMENT. took the side cover off and the NYLON actuator gear was in 3 pieces. got the parts, put it back together and WHOLA ..... FIXED.
good luck

 

[slodad]

Sure sounds like the power valve is stuck open. Its normal position should be closed and it should move easily with finger pressure.

 

[cnl83]

I should be able to pull the valve towards the front fender correct? IS there a diagram or something for kawasaki, so I can see whwat the actuattor soppose to look like? What gears? The actuator cover, only covered a lil hammer looking part, and a wheel.

 

[guts]

here is a diragram http://houseofmotorcycles.bikebandi...d~305468~model_dept_name~KX125(KX125K4)US.asp

here is one of the bottom http://houseofmotorcycles.bikebandi...d~305468~model_dept_name~KX125(KX125K4)US.asp

 

[cnl83]

Ok, ran it without the actuator cover, and the valve does come out and appears to working correctly. I took the valve cover off, and pulled the actuator and everything seems to be fine. I pulled the plug and its tan, with a lil spooge on the rim. That seems to be good to. I dont know what the heck to do. Im spent!

 

[QKENUF4U]

If you hammer it on choke it doesnt seem to do it as much.

5) Messed with the air screw

since its not as bad with the choke on then that shows its a bit lean. fatten it up with your air screw and try again. take it all the way in and come back out a 1/2 turn.
good luck

 

[cnl83]

I did that, and it didnt seem to bog as much, but it had no power.

 

[MX-727]

It's a lean bog. Try a bigger pilot.

Relatively new top end is realtive to how bad they wanted to sell the bike. Check the compression.

If it is anything like our '98 KX125, there isn't any power in the lower RPM's. Richen up the pilot circuit so it responds to throttle and then use lots of clutch to get to the power.

 

[cnl83]

Yes, I have to abuse to the clutch on it. So you think its a top end issue? I will check the compression and let you know.

 

[cnl83]

What should the compression be on the KX?

 

[nickyd]

what is it?

 

[Bodge]

Its lean, i highly doubt its a compression problem. Make sure it is not sucking any air in through the head, base gasket or the left side crank seal. I would definitly look at the left side crank seal. If there is any oil/gas mix under the left side engine cover, then the seal is toast.

 

[Colorado]

MX727's point was that the KX125 doesn't have a powerband below the point it hits the pipe. How much experience with 125 racebikes do you have?

When you say it boggs from idle, do you mean with the clutch disengaged, or under load? Most 125s require you to run the RPM up to the powerband, twist the throttle and shift a lot. If you're coming off a 4-stroke, a bigger bike, or a more enduro type setup, you might be expecting something from that little KX which it can't deliver.

 

[cnl83]

IT bogs under load, then if I shift a little early from second it will bog in third. Ive road quite a few bikes to know that this is not normal. For instance if im trying to get on it.. it will go...
BOOOOOOOOGGGG WAWNN! not normal.. it should be WOP WOP! WOP! lol.

 

[cnl83]

By pulling the cover off, am I going to be able to see if the seal is bad?

 

[Colorado]

Ive road quite a few bikes to know that this is not normal. For instance if im trying to get on it.. it will go...
BOOOOOOOOGGGG WAWNN! not normal.. it should be WOP WOP! WOP! lol.

Just checking. I bought a used KDX175 that idled okay, ran okay on the pipe at high rpm, but simply bogged in the midrange, and particularly at the transition to 3/4 throttle power. It made aproaches to jumps and coming out of turns eratic, and even a little scary at jumps because I might come down with my rear wheel over my shoulders if I missed the powerband.

A couple of people suggested that the powerband might just be all high like that, but I knew that it couldn't be THAT high. My plugs were usually pretty well colored, but would sometimes show just a little fouling. I played with the needle position, but could get only minor improvement. I went out and bought main jets in increments of 5 from 130 to 145 (it came with a 150) and finally got it (almost) right with a 135 main and the needle position in the middle. After that I read the manual and found out that the stock main is 138 (I'm at high alltitude, so leaning down is usually in order). I have NO idea why the last owner had a 150 in it! When I leaned down to 130 my midrange improved, but my top end tapered away.

Usually cutting out in the midrange is a sign of a rich mixture. I don't remember what jets your earlier post said you tried, or what the stock KX jets are, but pilot jets mainly effect idle. I would go back to the one it came with if idle was okay. I do remember that you said you changed your pre-mix to 40:1, but you didn't say from what. If you began at 50:1, that made your mix leaner. More oil means less air. If you began at 32:1, you made your mix richer --- which might be more of just what is creating your problem. I would try jetting leaner in the main and dropping the needle one groove from the bottom.

 

[Colorado]

I just reread your first post. What happened when you dropped down to 150 and 142? You only said that you tried it and went back to 160. If you lost top end power you went too lean. I would change jets in smaller increments, like a 155 next, then try different needle positions with each one. I told you that I lost top end at 130, and that was with the needle all the way up (clip all the way down). Raising the needle lets more mix in and gives you a richer combustion, lowering it leans it down.

Throttle valve cutaway also effects midrange, but unless someone changed the slide, that shouldn't be an issue. Do you have a book to see what the stock set up should be?

 

[cnl83]

My stock is 160 main and 40 pilot. I went all the way down the ladder to a 138 and moved the needle, but it never improved. It seemed when I went to the 150 I had more power, but it bogged more. I went from a mixture 50:1 30:1 and now im at 40:1.

No, dont have a book, but I called the local shop and they said it was stock.

 

[Colorado]

A thought just occured to me. I've never had this isssue on one of my bikes, so don't know if your symptoms match up. But a two-stroke requires primary compression in the crankcase which creates a slight vacuum in order to pull the fuel mix in durring the compression stroke. If mix (or enough mix) isn't pulled down, it won't be there to move up into the combustion chamber through the transfer ports. The vacuum is created on the upstroke, then as the piston moves down and closes the intake port, pressure builds to push the mixture into the combustion chamber.

Like I said, I haven't had the problem, but know that it is sometimes a diagnostic nightmare because everything else seems fine, but a bike just won't run right. A bad cylinder base seal, crank seal, or cracked crankcase casting can all result in this problem. To test it you remove the pipe and carb, then seal the openings and pressurize the crankcase with air. If it holds air it's fine, if not you just have to locate the leak and seal it. The rub is that you need special tools to seal and pressurize the crankcase, but you can make them yourself. I remember reading a thread here at DR a few months ago where one of the members described his fabricated setup and posted a picture. It would have been here in General Repair, in Vintage, or in Canadian Dave's KDX forum because those are the ones I read. You can try searching for it, or might want to start new threads asking about primary compression testing, equipment and symptoms.

 

[Colorado]

I pulled out one of my Clymer's. You seal the exhaust port, put equipment that will pressurize and measure the pressure of the motor on the intake side, pump 9lbs. of pressure in, then see if it holds the pressure for a few minutes. It shouldn't drop more than 1lb. in several minutes. If it drops 1lb. in a minute you know you've got trouble. It says you can often hear serious leaks, but can test for others with soapy water. Leaks can be in these places:
Crank seals
Spark plug
Cylinder head gasket
Cylinder base gasket
Carburetor base gasket
Reed cage gasket
Crankcase seal between the cases
Crack or porous alluminum crankcase castings

Good Luck!

 

[QKENUF4U]

6lbs MAX and 1 lb a minute leakage. more an you can blow your seals right out of the cases and cause other problems.
soapy water to find any leaks unless you can hear them well enough to find by ear/eye

 

[cnl83]

all screwed

Ok, today I went put a 150 jet in and found a lot more power, little less bog, but still there. I adjusted the air and it helped, but still bogged in first a lot, and the top end was really poor feeling, although it did draw a tear. I then put a 145 jet to see, and it ran, but spuddered, so I noticed an air sound coming from the left side, but wasnt sure if it was air or not. So I took it down the road, and it was horrible. After letting up off the throttle in 5th the engine died, so when I got slow enough, I put it in first, and released the clutch to start again. It started, but ran like crap. It was boggy, spuddery, and no power whatsoever, and it would not idle. It died on me, and I could not start it. So I pushed it back to my shop, and leaned up against something, and finally got it to start. I cannot get it to idle for anything. I put the stock jet back in, and still runs like poop, and wont idle. It seemed like it was running HARD or something..just a harder sound and feel. I dont hear any knocking though. So with all my previous post, and now knowing that something is really wrong. WHAT TO DO?

 

[cnl83]

I went back, checked the plug, and the plug was wet wet..
so its getting to much gas or something. There isnt any more resistance on the crank than before the screw up. I changed the plug and it was wet wet again. I red something on the internet about the crank case being full of gas, and having to turn it upside down to drain it.

Now I got it to run, after the 150th kick, but it ran like crap. If I killed it and try to kick it again, I gotta kick it 150 mre times.