1989 KX 80: Runs poor @ low rpm's

M

Midhigh

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Jul 19, 2002

481

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• Oct 14, 2002

• #1

Can anyone give me suggestions on getting this bike running better at lower rpm's. Off the start it is very very suggish. Once you get on the pipe it explodes. It has a new FMF fatty pipe and silencer. jetted at 122 jet. I run 36:1 fuel/oil mixture.
Any suggestions?? please help

 

G

Glitch

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Dec 3, 2001

630

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• Oct 14, 2002

• #2

Does it seem to be running rich or lean down low or just plain sluggish. It could be your reeds, is the bike hard to start? Maybe the topend is bad and needs replacing. Just some thoughts.

 

M

Midhigh

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Jul 19, 2002

481

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• Oct 14, 2002

• Thread starter
• #3

It runs rich, sluggish

 

I

IrishEKU

A General PITA.

LIFETIME SPONSOR

Apr 21, 2002

3,806

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• Oct 15, 2002

• #4

Lean out the jetting, the fich condition is from the pipe. As for being sluggish at starts it probably is your clutch.
Phillip

 

M

Midhigh

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Jul 19, 2002

481

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• Oct 15, 2002

• Thread starter
• #5

I rejetted from 130 to the current 122(just this week & haven't run it alot yet). Should I go even leaner on the jetting? And I will look at the clutch. That makes sense to me from the way it runs. Thanks

 

B

bbilliot

Member

Oct 25, 2002

12

0

• Oct 28, 2002

• #6

Try going down one on the pilot jet.

 

L

lwsmithjr

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Sep 18, 2002

194

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• Nov 13, 2002

• #7

You may have solved thisproblem already but I'll offer my $.02 worth anyway. We had an '88 KX80 that was just the opposite: good on bottom but terrible on top. It seemed to be extermely rich and would foul plugs at the drop of a hat. Come to find out, the high speed coil on the stator was bad. Yours could be just the opposite.

 

M

Midhigh

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Jul 19, 2002

481

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• Nov 14, 2002

• Thread starter
• #8

Thanks for your help, But I am not versed in the dirt bike maintence lingo. What is the high speed coil on the stator? and is their a low speed coil on the stator? Where is the stator located and what does it look like?

 

M

Midhigh

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Jul 19, 2002

481

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• Nov 14, 2002

• Thread starter
• #9

And what does the stator do?

 

L

lwsmithjr

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Sep 18, 2002

194

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• Nov 17, 2002

• #10

The stator is the device that produces a voltage to the coil in order for the spark plug to spark. It is located under the flywheel which is behind the left side engine cover (next to the shift lever). You have to pull off the flywheel to get to the stator, which requires a flywheel puller. On our '88, the stator had a coil that produced energy for slow RPM's and another one for high RPM's. You can go to www.buyakawasaki.com and see a parts diagram for your bike. However, after thinking more about this, I'm not sure the bike would even start if the low speed coil was bad. A service manual could tell you the procedure for testing the stator or a competent shop could test it for you. We bought a used one from a bike junkyard for $75.00. There are also companies that rebuild them (they are listed in the back of most bike magazines). Based on all that you've done, and the fact that it just started out of the blue, I still think it's electrical, even if it's not the stator.

 

B

bbilliot

Member

Oct 25, 2002

12

0

• Nov 20, 2002

• #11

Try going bigger on the pilot jet. That is what controls from 0 to 1/8 throttle. I had to go bigger on our 01 KX85. It would bogg off the bottom.

 

M

Midhigh

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Jul 19, 2002

481

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• Nov 20, 2002

• Thread starter
• #12

I tried that too. But it runs way to rich. Fouls plugs in a heart beat.

 

M

Midhigh

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Jul 19, 2002

481

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• Nov 21, 2002

• Thread starter
• #13

OK the verdict is in. After many attempts to find the right jetting, new clutch friction plates and cable, reeds, gas mixtures, and air filter. The bike still did not run right. The New (yes i said new) FMF pipe came up with 3 cracks and the mount snapped. It occured to me that the exhaust sound was a little odd. I had noticed it before, but wasn't that concerned and was going to replaced the o rings on the pipe once I got the jetting figured out. Well!!!! One of the motor mount bolts was cracked thus giving the motor some unwanted vibration. Thus cracking my pipe and Giving the motor and Carb fits. After reworking the motor mounts and welding on a brand new (I did say it was new didn't I) FMF pipe, the bike smoothed out. Anyone need a new stator for a 89 KX 80?

 

L

lwsmithjr

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Sep 18, 2002

194

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• Nov 22, 2002

• #14

Sorry!!! I guess that explains why it just started running bad all of the sudden. My son broke the motor mounts on his CR80 (twice) and the resulting twist of the engine, pipe ect. almost poked a hole in the exhaust. There is a nice round indentation from the cylinder head bolt. Sorry about the mis read on the electrical. It just seemed you had chased all of the likely possibilities.

 

M

Midhigh

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Jul 19, 2002

481

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• Nov 22, 2002

• Thread starter
• #15

No Problem on the stator. I welcome any help. Thats what these forums are for. i'm just glad I finally got it worked out. Thanks for all your imput.