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Discussion Starter #1 (Edited)
During maintenance on my 08' I decided to clean the carb, at the time this seemed like a bright idea. While cleaning it, I decided I should put in a jet kit, this also seemed like a bright idea. So i ordered the kit and a week later it was time to put the carb back together again.

Now here is some don'ts for those of you who want to clean your carb.
1. Don't clean it unless you have a parts schematic so you know where everything goes.
2. Especially don't use compressed air if you don't have the above mentioned! (guess how i know this)

So I used the dynojet kit, did it to their manual, used their 138 jet, clipped their needle on the seccond spot from the top, and drilled out the slide with their drill (opinions on this please), and set the mixture to 2.5 turns out. I have a no-toil air filter, drilled out muffler (1.75" hole drill to the back i think it was). And otherwise nothing notable yet.

I am now 99.99% positive all parts lost with compressed air are back in the carb. (needle jet, and washer and o-ring on mixture screw). Currently I'm in the progress to return everything to stock (undrill the slide) When I had it together with the dynojet stage 1 It would idle properly and run properly probably up to 4k rpms (standing still no load) But if from idle i would pin the throttle to max it would should up to 8k rpms then fall back down to 4.5 k with an annoying exhaust noise and some smoke.

Ok so i'm hoping that returning the carb to stock will bring my bike back. I've had this carb apart a good 10~15 times now. So if anyone has any opinions. give em!

Edit: Just some more background, while i ran the engine with the stage 1 i also took of the airbox door and tried without the filter to see if it was an intake problem with the same results.
 

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Sounds like you may have a DIAPHRAGM AIR LEAK, possible when the diaphragm isn't seated correctly in its groove . . .

While I'm not a consummate fan of jet kits, nothing in the kit should produce the symptoms you describe; the jet kit remains, in my view, not inconsistent with the, "First, do no harm" tenet of the motorcycle tinkerer's oath.

Adjust and reassemble carefully; you should be good to go.

Excellent "schematics" are available at http://www.kawasaki.com , owner info, view parts diagrams; excellent photography is available from klrworld.com http://klrworld.com/forums/index.php/topic,2333.0.html ; and . . . a good treatise on the CVK40 can be found by Googling, "Care and Feeding of the CVK40." http://www.gadgetjq.com/keihin_carb.htm

Do not despair.

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You ask specifically about drilling the slide; enlarging the vacuum port to 7/64" diameter appears rather benign, to me; may improve throttle response, but . . . not culpable for your problems, IMHO. Wouldn't JB Weld the hole and re-drill myself; I'd hold what I've got in this department, if I were in your place.
 

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xjdubber-
not sure if this helps with your carb problem, but I just installed a JD needle/jet kit and used his recommendations of a 160 main with the needle set in 2nd from top position (also drilled the slide). Runs very well and noticeably stronger than stock. I opened airbox as well, but did not mod the exhaust.
 

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Discussion Starter #5
You ask specifically about drilling the slide; enlarging the vacuum port to 7/64" diameter appears rather benign, to me; may improve throttle response, but . . . not culpable for your problems, IMHO. Wouldn't JB Weld the hole and re-drill myself; I'd hold what I've got in this department, if I were in your place.

I've just checked the diaphram thorougly no holes or tears in the rubber, when i put her back together ill use some silicone grease on the sealing edges to get a better seal that way, the drill supplied with the jd jet kit is bigger than 7/64 close to 1/8 actually. that is why i am going trough the jb weld process. it just about dry right now might give things another try tonight. I guess the other thing could be the choke circuit not sealing of correctly. Right now i have the cable adjusted as far out as it will go, so it should not be a problem but you never now.

PS: Despair set in long ago
 

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Discussion Starter #6
xjdubber-
not sure if this helps with your carb problem, but I just installed a JD needle/jet kit and used his recommendations of a 160 main with the needle set in 2nd from top position (also drilled the slide). Runs very well and noticeably stronger than stock. I opened airbox as well, but did not mod the exhaust.
DJ and JD to diffrent kits, I wish i would have known about the JD kit, it has a much nicer needle and uses stock keihin jets. The Dynojet Kit does not.
 

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Are you absolutely sure that all three pieces in the top of this photo (which I pirated from Redondo Ron) went back in? Especially the collar, which falls out when you're not looking and rolls under the workbench?



The collar is certainly launchable with compressed air...

T
 

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Discussion Starter #8
Are you absolutely sure that all three pieces in the top of this photo (which I pirated from Redondo Ron) went back in? Especially the collar, which falls out when you're not looking and rolls under the workbench?


The collar is certainly launchable with compressed air...

T
It is definitely launchable with air! The little o ring and washer on the mixture needle as well! Managed to find them back though.

Just put it back together epox'ed the hole and tried to drill it out smaller but I just pushed the epoxy out with the drill. She runs better, I'll have to take it for a drive tommorow. Still when i blip the throttle she rev's to 8k then dips to 5k. Do these things have rev limiters, that could cause that i guess. Tommorws drive will tell.
 

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As far as I know, the only rev limiter is valve float :^)

T
 
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Your bike, xjdubber, but . . . re-doing your slide drilling, to me, is a waste of JB Weld.

Our Harley bretheren drill their slides to 1/8" all the time on their similar Keihin CV40 carburetors; the vacuum port only facilitates low-pressure transfer above the diaphragm, can't see how drilling it even to 1/8" diameter could produce your symptoms.

Like Tom Schmitz, I've always thought the "rev limiter" on a KLR650 was the valvetrain only!

I think you have a systemic problem, your carb isn't mixing air and fuel correctly at higher mid-throttle operation; here's hoping you find its cause and cure.

As to the diaphragm installation, some use Vaseline or the like to help hold the squishy thing in its groove; I've found it an elusive little beast, myself!
 

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Discussion Starter #11
I don't see why the actual size of the hole matter either, but there is talk on other forums that it does. Im leaving the hole the size it is now, don't really believe it is the problem either. Used some silicone grease to hold the diaphragm in place, it basically the same as vaseline. I wish I had'nt touched the thing! First carb I touched was a mukini vm38 I now know that one inside out (it had been tinkered with before i bought that dirtbike, cost me a piston), I'm guessing ill soon be dreaming about cv40's too. If tommorows drive proves there is still an issue, which i think there is, I'll be taking it apart again and lay out every part according to the carb diagram.
 

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I don't see why the actual size of the hole matter either, but there is talk on other forums that it does.
Well then, xjdubber, I'd dare not contradict what you gleaned from the authoritative, knowledgeable members of "other forums!"

I would, however, dare meekly and respectfully asking these experts, HOW would 1/64" diameter increase in a passive orifice affect carburetor operation, and what the magnitude of the effect might be?

Once this knowledge were divulged, one might share it with the manufacturer of your jet kit, delivering them from their error.

Also, the information could be printed on cardboard signs, posted in every Harley dealership shop and "chopper-shop" garage, nation-, and even world-wide. (Sadly, at present, every Harley (with a CV40) entering the service bays of my neighborhood independent chopper shop routinely receives the 1/8" slide drilling, and fuel screw adjustment; bet this procedure is widely repeated).

Similarly, I would not contradict the experts on the other forums when they tell you the PCV valve mod offers you increased power, lower oil consumption, enhanced engine compression braking, better ring seating, improved fuel efficiency, etc., etc. Yet I would again (meekly and respectfully, of course) ask them HOW the device performs these wonders, pointing out crankcase vacuum isn't involved, since none has been detected in credible tssts).

Finally, I would not challenge the belief that without a Thermo-Bob, a KLR650 engine will grenade; turn into a pumpkin, alter the metallurgy, strength and durability characteristics of all associated molecules (matter suffering the dread effect of "thermal shock"), and that any KLR owner declining a Thermo-Bob shall suffer a lingering, painful death whereupon his soul will suffer the searing fires of eternal damnation . . .

One can learn a lot from those "other forums!"
 

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Similarly, I would not contradict the experts on the other forums when they tell you the PCV valve mod offers you increased power, lower oil consumption, enhanced engine compression braking, better ring seating, improved fuel efficiency, etc., etc.
Don't forget lower cholesterol. ;)
 
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Discussion Starter #14
Well then, xjdubber, I'd dare not contradict what you gleaned from the authoritative, knowledgeable members of "other forums!"

I would, however, dare meekly and respectfully asking these experts, HOW would 1/64" diameter increase in a passive orifice affect carburetor operation, and what the magnitude of the effect might be?

Once this knowledge were divulged, one might share it with the manufacturer of your jet kit, delivering them from their error.

Also, the information could be printed on cardboard signs, posted in every Harley dealership shop and "chopper-shop" garage, nation-, and even world-wide. (Sadly, at present, every Harley (with a CV40) entering the service bays of my neighborhood independent chopper shop routinely receives the 1/8" slide drilling, and fuel screw adjustment; bet this procedure is widely repeated).

Similarly, I would not contradict the experts on the other forums when they tell you the PCV valve mod offers you increased power, lower oil consumption, enhanced engine compression braking, better ring seating, improved fuel efficiency, etc., etc. Yet I would again (meekly and respectfully, of course) ask them HOW the device performs these wonders, pointing out crankcase vacuum isn't involved, since none has been detected in credible tssts).

Finally, I would not challenge the belief that without a Thermo-Bob, a KLR650 engine will grenade; turn into a pumpkin, alter the metallurgy, strength and durability characteristics of all associated molecules (matter suffering the dread effect of "thermal shock"), and that any KLR owner declining a Thermo-Bob shall suffer a lingering, painful death whereupon his soul will suffer the searing fires of eternal damnation . . .

One can learn a lot from those "other forums!"
I completely agree with you on all counts and have at least one other to add, but that is for another time. I simply wanted to try it as I was out of options.

Anyways i took it for a ride. got upto 130 km's pretty quickly things seem to be back in order. After dinner I'll pull out the plug and take a look at it. I didnt ride it very long but color should have altered a little anyways ( i rode it hard) power seems back to normal still would like to have more. Still have the annoying popping after letting of the throttle. Im going to leave it for now and carry on putting the bike together.

Ok so maybe I will get into that other KLR thing, what is people's opinion on the "doohickey" here. I was and i still am not a believer in it, however I did change mine out. Now the spring still had some tension on it but not much, which really i see as a maintenance thing, I do believe it could probably have gone another 5 to 10,000 km's on it. But this whole thing of the balancing lever breaking i'm not seeing it In my 08' the balancing lever is quite beefy.
 

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The Gen2 lever is very unlikely to break; it's the spring that is the issue. The lever is a bit sloppy on the shaft, but it gets the job done.

T
 

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Discussion Starter #16
Well plug is deffinitely cleaned up i can see the ceramic again, I'll drive her for a while now and pull it again to see if it is tan or not. Thanks for the help guys!
 

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Here's hoping your carburetor issues are behind you. As far as the doohickey, Tom explained it well. The Generation II KLR's are in their fourth year of production, and I have yet to see or hear of a doohickey lever breaking,[Gen II] wearing out the concentric shaft, or eating an engine case. The spring that tensions the lever should be replaced at some point. But those facts doesn't sell many doohickey's, so little is said about it. Like new Harley owners buy lots of T-shirts, new KLR riders buy lots of doohickeys.
 

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Discussion Starter #18
Here's hoping your carburetor issues are behind you. As far as the doohickey, Tom explained it well. The Generation II KLR's are in their fourth year of production, and I have yet to see or hear of a doohickey lever breaking,[Gen II] wearing out the concentric shaft, or eating an engine case. The spring that tensions the lever should be replaced at some point. But those facts doesn't sell many doohickey's, so little is said about it. Like new Harley owners buy lots of T-shirts, new KLR riders buy lots of doohickeys.
Harley owners buy a lot more than just t-shirts :) At least I have this beautifull sticker now that says "I've got the fix". Rather would have grabbed on of 100's of diffrent springs I have in my shop. Whats that saying again....You live you learn I think it was?

As long as there is something mechanical there will always be those who want to improve upon it. (The service manager at my work place says I would reinvent the Lord's prayer if it was up to me). Oh well on to the next farkle.
 

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I have a 1999 Kawasaki KLR 650.When I bought it it was barley running.Tye previous owner said it needed a carburetor kit.I took the carb apart and found rust and a bad float valve which was stuck.I cleaned the jets and put a new float valve and new gasket on the float chamber.After installing and and turning the fuel on fuel runs out of the carb out the bottom of the air filter through a drain tube.I don't know what I'm doing wrong.Any suggestions?
 

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Is the drain screw closed and sealing?

If so, then . . . you have a float valve leakage issue most likely, IMHO.

Is the float valve tip supple and rubbery? If instead, the tip is hard and unyielding, the component may be incapable of sealing.

Is the float valve seat clean, smooth, and uniform? If not, sealing is unlikely.

Are the floats unperforated, filled with air instead of gasoline? A punctured float will cause excessive fuel overflow.

Is your float level correct? I commend to you, Tom Schmitz's excellent videos (click on colored text below):

http://www.klrforum.com/how-tos-tech-guides/19026-carb-overhaul.html

I can't think of other causes (than open/leaking drain screw, defective float valve/float valve seat, punctured float, incorrect float valve height) for a carb puking fuel; anyone?
 
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