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Author Topic: 91` 125 wont rev  (Read 8224 times)

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Offline Jopiz

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91` 125 wont rev
« on: June 18, 2009, 02:48:33 AM »
I have struggled with the problem for about a week. The problem is that my bike wont rev to higher RPMs than 6000. It just sputters and loses power instantly. Pulls pretty strong below 6000 RPM. Jetting is fine. I have tested compression and got 167 psi. I replaced the ignition coil and it runs a little bit better. It fouls a plug in 5 minutes. Smokes alot and spits oil/fuel mixture through exhaust. It doesnt lose any transmission fluid so wet side main seal isnt leaking. Carb is OK and reeds are tight. It simply feels like it has an RPM limiter at 6000 RPM. Stator, flywheel, igniter, pulse coil and ignition coil has been tested and verified to be operating fine. Starts first kick without choke. I can even start it with my hand but still it has lots of compression. The crankcase hasnt been pulled apart. Im sure it doesnt leak.

Any thoughts what could cause my problems?  :mrgreen:
« Last Edit: June 18, 2009, 02:52:25 AM by Jopiz »
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #1 on: June 19, 2009, 08:42:34 AM »
Can KIPS cause my problems? If it is stuck or somehow not moving so it blocks the exhaust ( KIPS in in normal closed position). I had to replace the rod that operates KIPS because it was bent and the threads were damaged. If i lock the KIPS fully opened does it start? I know it will lose loads of low end.

-Jopizz
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Offline BullKaw

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Re: 91` 125 wont rev
« Reply #2 on: June 19, 2009, 09:24:56 AM »
What brand of tach are you using? What is the max rpm suposed to be?
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If you don't have time to do it right the first time, when are you going to have time to fix it!

Offline Jopiz

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Re: 91` 125 wont rev
« Reply #3 on: June 19, 2009, 09:32:07 AM »
Im using KOSO ATV meter for speed, temperature and tacho. Its very reliable. Im not sure about the exact max RPM. But i know its well past 10k.
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Offline pickledkiwi

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Re: 91` 125 wont rev
« Reply #4 on: June 19, 2009, 09:43:53 AM »
Lock your KIPS open or disconnect it. Doesn't matter too much. Do what ever is easiest. If you get more rpm with it locked open then it wasn't opening properly in the first place. If you disconnect it and get no rpm change at all then it wasn't working in the first place!

Might pay to check your muffler first. The center tube may have collapsed and is restricting gas flow at higher rpm.

PK
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #5 on: June 19, 2009, 09:49:10 AM »
I just rebuilt it. The packing has been used for about 20 min of driving time. The center tube in my muffler is perfectly in place.

-Jopizz
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Offline pickledkiwi

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Re: 91` 125 wont rev
« Reply #6 on: June 19, 2009, 10:11:52 AM »
When you checked the electrical stuff was it bench tested or swapped to another bike to check for changes.

PK
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #7 on: June 20, 2009, 02:12:31 AM »
No official bench testing by Kawasaki dealer. Ignition coil is completely new. Pulse coil is just a simple coil that i checked with an oscilloscope. I also tested the CDI with a Hz generator and with an oscilloscope. I got exact readings what i was looking for. Stator works. Flywheel also.

Heres a couple pics of my spark plug. New plug is only for reference. The plugs are BR10ECS. I wiped any excess oil. The color is something like dark brass or bronze. I found it very strange. Click photo to get a larger image. The insulator is totally black.





-Jopizz
« Last Edit: June 20, 2009, 03:33:31 AM by Jopiz »
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #8 on: June 20, 2009, 06:22:17 AM »
The bike refused to start. I took the carb out and disassembed it. Main jet had found its way out. Also the pilot jet was completely clogged. I put everything back together. It fouled one plug. It ran about 2 seconds and died. Smoked like hell. I started it numerous of times (runs 2 sec and dies). Until got it running. It burned all the excess oil out of the pipe and reved nicely. Much better than it used to be. I noticed the governor rod wasnt moving at all. I have to try and lock the KIPS in opened positon. Lets hope its the issue. 

 :mrgreen:

-Jopizz
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #9 on: June 21, 2009, 12:34:55 AM »
Max RPM 6700. It just doesnt rev more. KIPS was locked in open position. 98 octane gas with Belray h1r 1:32 mix. Im starting to get frustrated. Doenst smoke as bad as it used to. d**n. I have to change the spark plug cap for non resistor model. Ill just try to eliminate these things. I got fuel, i got spark and i got good compression. What could possibly be wrong?   :oops:

Guys give me some ideas!

-Jopizz
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Offline Hillclimb#42

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Re: 91` 125 wont rev
« Reply #10 on: June 21, 2009, 12:50:43 AM »
 It sounds like a carb problem still. Try not to eliminate possibilities too quickly. 1st you said jetting was fine, but the main fell out and the pilot was clogged. :? Is the fuel fresh?
 What's up with the powervalve? it doesn't open and close on its own? Full of goop? All that it would take is some  debris holding the float open or clogging the jets. Having a main thats too rich would also be something to chase around. Air filter is clean? its something simple, probably in the carb. Choke is operating correctly right?
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #11 on: June 21, 2009, 01:15:55 AM »
Jetting is fine 158 main, 55 pilot, float level correct 16mm. Air filter cleaned and oiled (not overoiled). Fuel is about 8 hours old. Choke operates correctly. Kips works. I just tried to lock it to fully open to be sure its not the issue. There is a problem in the Kips operating thing. It doesnt close or open on its own. It moves a littlebit though. It may just be that i havent got enough RPM to get it moving.

 I just cannot understand how the mainjet fell out and pilot was clogged. I ran it only for about 20 minutes.

-Jopizz
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Offline Hillclimb#42

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Re: 91` 125 wont rev
« Reply #12 on: June 21, 2009, 01:42:20 AM »
stock pilot is a 48. any debris in float needle would keep the flow going. the powervalve not working with rpm's is probably the biggest thing to take care of. mine open quickly and look like they will shoot out of there. You are getting wet /black plug readings?
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #13 on: June 21, 2009, 01:46:47 AM »
The stock pilot is 55. I checked it. 48 is Stock for 92?. I'll go and check the plug. I'll post a picture later. In what RPM does your powervalve open? Fully open at 6000?
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Offline Jopiz

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Re: 91` 125 wont rev
« Reply #14 on: June 21, 2009, 06:13:36 AM »
Yeah! The RHS crank seal was gone! It sucked 8 dl of transmission fluid through it in just 20 minutes. Problem solved all by my own  8-)

Thanks for help.

-Jopizz
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