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Rjg967

KLR650 persistent issue, help!

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Okay folks, I've tried nearly everything. And I've even almost worn out the parts cannon. I'm hoping someone might have an idea. 

1999 KLR 650, has no power above 4K RPM. Runs perfect 1000-4000, no popping, missing, or otherwise. Here is what I've done: 

Thought carb at first, cleaned and installed new diaphragms. Gave up and installed new carb.

Thought maybe ignition related, new plug, then new coil, then new CDI. 

Thought maybe a power issue as I've seen fluctuating charge power. New charge coil and pulse coil. 

Checked compression, lower end of good. 

 

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The new parts....OEM or the cheapest Chinese shi...stuff? 

New stator, but did you test/replace the voltage regulator?

What numbers are "lower end of good" compression?

Have you done a leak down test?

Valve clearance check?

What color is your milk crate?

  • Haha 1

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Mix and match with OEM and Chinese. Some stuff just isn't available OEM. 

The regulator is replaced. 

As per spec, with compression release active, 80-110, I am at 92. 

No leak down, runs too good in the bottom end.

Valve clearance is okay. 

Milk crate N/A, too rich for my blood.

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I suggest getting the milk crate, it’s mandatory! 
I’ve had some new Chinese parts that worked flawlessly and other stuff was out of spec right out of the box.  Seems like your compression numbers are good, low compression would cause more starting issues than higher rpm problems.

Sounds like an electrical problem, having a buddy with a good running KLR and moving parts around would be ideal to see if the issue moves from bike to bike.  Some of the parts are not easy to test, CDI for instance.  
 

Good riddle to solve here, keep posting up.  I’m always interested in finding the solution. 

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When you are ready, I'll sell you my 790 for a stupid low price. 

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Starving for air?  Filter?


Or fuel? Petcock ok? Petcock filter? Fuel line kinked? Gas cap vent not venting?

intake boot?

did you do some maintenance recently? Could timing be off?

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6 hours ago, kato said:

Starving for air?  Filter?

BRAND NEW UNI FILTER
Or fuel? Petcock ok? Petcock filter?Fuel line kinked? Gas cap vent not venting?

IMS TANK WITH A NEW CAP, 1-YEAR-OLD NON-VACUUM PETCOCK

intake boot?

NO VISIBLE TEARS, MIGHT TEST WITH STARTING FLUID WHEN RUNNING.

did you do some maintenance recently? Could timing be off?

WORTH CHECKING, WILL CHECK CAM TIMING. 

Thanks for your input! Opened a couple avenues of thought, will pursue.

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7 hours ago, Pokey151 said:

When you are ready, I'll sell you my 790 for a stupid low price. 

Not allowed, you need to keep that for longer runs. Whether it's my KLR or something else, the highway miles will eat that 500 up 

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I had a customers bike that was doing the same thing.  I cleaned the tank, petcock, carb, and fresh gas but I didn't clean the air cleaner because he said he just did it and it looked fresh.  Long story short, I decided to clean it anyway and found out that he had over oiled it and it wasn't getting enough air.

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3 hours ago, Rjg967 said:

Not allowed, you need to keep that for longer runs. Whether it's my KLR or something else, the highway miles will eat that 500 up 

I would get something else. I miss my Harley 

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50 minutes ago, cj54x said:

I had a customers bike that was doing the same thing.  I cleaned the tank, petcock, carb, and fresh gas but I didn't clean the air cleaner because he said he just did it and it looked fresh.  Long story short, I decided to clean it anyway and found out that he had over oiled it and it wasn't getting enough air.

Sometimes we overlook the simple stuff, I know it's bitten me a few times. 

Once I was working on a DRZ400 that seemed sluggish, did a bunch of stuff before I checked the oil and found it way overfilled (the vacuum petcock failed and filled the crankcase with gasoline).  

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So I thought that was the case in the beginning, so I cleaned and reoiled the filter. 

Then just recently, after a couple of slow rides, I decided to throw in a brand new uni filter, I used the spray oil, same way I've done filters for the last 20 some odd years.

I even cleaned the wire mesh screen in the air box

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Maybe try running it around the block with no air filter and see if that makes a difference?

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The 'ol mule used to do that when the carb diaphragm developed a tear. It would run great until ~4k RPM or so? Then the throttle just didn't do anything, like it hit a wall. I had to replace the slide assembly 3 times over ~70k miles if I remember (can be bought from a Harley dealer for 1/2 price of Kawi part). Guess the new carb rules that out though. :(
image.thumb.png.6d3b9463a10a94b529c4e79b47ee5d3c.png

Any other source of vacuum leaks? Does the new carb have the petcock vacuum port capped like the original?

When you say 'no power' you mean it won't climb RPM anymore? Or it chugs/surges/misfires? What exactly does it do after 4k?

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1 hour ago, bfar33 said:

The 'ol mule used to do that when the carb diaphragm developed a tear. It would run great until ~4k RPM or so? Then the throttle just didn't do anything, like it hit a wall. I had to replace the slide assembly 3 times over ~70k miles if I remember (can be bought from a Harley dealer for 1/2 price of Kawi part). Guess the new carb rules that out though. :(
image.thumb.png.6d3b9463a10a94b529c4e79b47ee5d3c.png

Any other source of vacuum leaks? Does the new carb have the petcock vacuum port capped like the original?

When you say 'no power' you mean it won't climb RPM anymore? Or it chugs/surges/misfires? What exactly does it do after 4k?

It's worth inspecting again. 

No surging, misfires, or anything. Runs amazing but gutless, but absolutely WFO the best I've been able to get is 62 mph.

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So weird, that's exactly the way it used to present when it had that issue in the past. Sometimes the tear was small and could only be seen when I stretched the diaphragm a bit like shown above and looked for light coming through. Good luck

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On 5/8/2024 at 8:37 AM, Pokey151 said:

I would get something else. I miss my Harley 

Hey Pokey151 - Everyone should have a Harley or two in their stable for the long rides.  

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46 minutes ago, J5ive said:

Hey Pokey151 - Everyone should have a Harley or two in their stable for the long rides.  

I agree,  I've owned 2 in my life, I would like another.  Not in a rush, but a year or 2 out

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My KLR did the same, I would be cruising on the freeway at 50-60. If I opened it up to make a pass it wouldn't go. The problem was I rebuilt the carb and didn't get the diagram seated in right causing a leak when I tried to go full wide open. The vacuum was not able to draw the needle all the way up and open. I also put in a manual fuel petcock to not use the vacuum operated one.

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If you have an air compressor, you can easily check if the slide/diaphragm is installed correctly and working right.  Use an air nozzle and put about 10-20 psi in the port at the top backside of the carb.  The slide should rise, when you release the pressure it should drop.  I usually try to slowly modulate the air pressure to see if it goes up smoothly. 

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