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I have a 88 klr 650. I took the carb apart, cleaned it and put it back together. I cannot get the main jet to screw all the way in. Threads still showing. Not sure if it is supposed to or not. Bike is running terrible. Wont idle until very warm. Backfiring. Etc. I can't tell from the service manual. Can somebody send me a pic?
Thanks Again!!!!!!!!!!!!!
 

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Dunno if you have stock Keihin carburetor main jet or not. Some will seat flush, aftermarket may have threads showing once seated. Lets suppose the main jet is set in place OK.




Sounds like your issue may be in the idle speed circuit. Do you have stock exhaust on the bike? Is the air filter in place, making a proper seal at the intake? If "yes" to both, try setting the idle circuit screw 2.25 turns out from gently seated. A too lean of a setting in the idle circuit will effect idle and may create deceleration popping. Popping can also be created from an improperly sealed exhaust system. More information regarding exhaust and air cleaner modifications are needed to make any exacting recommendations.

 

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Discussion Starter #3
Need Carb Help

My main jet is set just like the one in the pic. The air filter is new and properly installed. Have not checked the exhaust yet. Bike only has 7000 miles on it though. Still stock. Tried the 22cent mod. Didn't help although the bike had great throttle response through the entire range. When I turned the idle mixture screw to 2.5 turns, the problem got worse. Put a new plug in too. Checked the timing. It's right on. Changed all the petcock parts too. This whole problem started when the float stuck in the carb. I changed it and the bike hasn't run the same since. Measured the float height. It's right on. Just can't figure it out. Keep the info coming.

Thanks Again!!!!!!!!!!
 

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My main jet is set just like the one in the pic. The air filter is new and properly installed. Have not checked the exhaust yet. Bike only has 7000 miles on it though. Still stock. Tried the 22cent mod. Didn't help although the bike had great throttle response through the entire range. When I turned the idle mixture screw to 2.5 turns, the problem got worse. Put a new plug in too. Checked the timing. It's right on. Changed all the petcock parts too. This whole problem started when the float stuck in the carb. I changed it and the bike hasn't run the same since. Measured the float height. It's right on. Just can't figure it out. Keep the info coming.

Thanks Again!!!!!!!!!!

Choke stuck maybe, it's pretty easy to break the plastic sleeve on the carb or the cable is hung up somewhere?

Vent lines on the carb clear?

Does your carb have a coast enricher? Not sure how it works in relation to the low speed circuit (pilot jet and air screw) but somethings not right in that circuit.
 

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Go back and make sure the diaphragm is seated correctly, is not ripped, or have hole in it. Usually this shows up when the carb moves off of idle... not at idle.

So far, this carburetor has had the float replaced, the enricher [choke] has been replaced. You later discovered the needle jet was missing. It has been cleaned a number of times. You've done the .22 mod. Maybe describe how that .22 mod was performed. That will take us to that diaphragm thing again. Usually if there is a problem in successfully completing that modification, the problem is found in the re-installation of the slide / diaphragm.

Back to the air filter. What brand of air filter? You said it was new, but have not came forth with WHAT BRAND? And was it oiled as instructed? This air filter thing can be very crucial. Some bikes do not run worth a tinker's dam with certain air filters.

The bike sat somewhere for 15 years. Have you checked the carburetor manifold boots with carb cleaner while the bike is running for air leaks? It is not beyond an unreasonable thought that the boots may have developed air leaks from cracks, etc. 15 years sitting can be worse than 15 years of being ridden.
 

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Go back and make sure the diaphragm is seated correctly, is not ripped, or have hole in it. Usually this shows up when the carb moves off of idle... not at idle.

So far, this carburetor has had the float replaced, the enricher [choke] has been replaced. You later discovered the needle jet was missing. It has been cleaned a number of times. You've done the .22 mod. Maybe describe how that .22 mod was performed. That will take us to that diaphragm thing again. Usually if there is a problem in successfully completing that modification, the problem is found in the re-installation of the slide / diaphragm.

Back to the air filter. What brand of air filter? You said it was new, but have not came forth with WHAT BRAND? And was it oiled as instructed? This air filter thing can be very crucial. Some bikes do not run worth a tinker's dam with certain air filters.

The bike sat somewhere for 15 years. Have you checked the carburetor manifold boots with carb cleaner while the bike is running for air leaks? It is not beyond an unreasonable thought that the boots may have developed air leaks from cracks, etc. 15 years sitting can be worse than 15 years of being ridden.

You have privillaged info or are you clairvoyant? :49:
 

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You have privillaged info or are you clairvoyant? :49:
Just fortunate to have enough active cells to utilize the part of my brain that houses recall and memory. Not always optimally.

The OP has started five threads on this forum, four of which were relating to the fuel delivery system on this bike. I responded to each of those threads. I offered suggestions and proposed remedies to each posted carburetor related request for information and assistance.

A search of the OP's posting history on this forum should confirm what I have stated.
 

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My main jet is set just like the one in the pic. The air filter is new and properly installed. Have not checked the exhaust yet. Bike only has 7000 miles on it though. Still stock. Tried the 22cent mod. Didn't help although the bike had great throttle response through the entire range. When I turned the idle mixture screw to 2.5 turns, the problem got worse. Put a new plug in too. Checked the timing. It's right on. Changed all the petcock parts too. This whole problem started when the float stuck in the carb. I changed it and the bike hasn't run the same since. Measured the float height. It's right on. Just can't figure it out. Keep the info coming.

Thanks Again!!!!!!!!!!
Yo, dawgslife! Any success yet? We ain't out of bandwidth or ideas yet. keep us posted.
 

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Discussion Starter #9
No Success Yet. I am beginning to thing it's something electrical. Is that possible? I may break down, load it on the trailer and bring it to a Kawasaki dealership for repair. Weather is awsome for riding right now. I want to ride!!!
 

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where are you located? [roughly]?

The reason I ask is that I have had better luck with independent shops diagnosing and repairing situations like this than I have had at a franchised dealer. Often the dealer tech's experience is limited to maintenance, after market doo-dad installation and warranty issues, which in this day and age, come complete with a listing of wrench sizes and step by step process guide lines. Little need for investigative skills. A Japanese bike specialist might be the ticket.

I still believe your problems are in the carburetor. Achieving a balance. If you have a digital camera it might help some. Try to get us more history on this bike.....like, why was it parked way back when? Could there of been a mechanical problem, and they just walked away and left it sit? Are there any modifications on the bike that might lead you to believe that any jetting has been done? Is the air filter a Kawasaki air filter? Is the muffler a stock Kawasaki muffler? This is some critical information. If you have to pay someone to figure these things out, it could get spendy. They may opt to start replacing things until they hit on an answer. I don't like that to happen with my money. I like my money to go to gas and tires, not someone's guesstimate they bill for to the nearest decimal point.

Take a breath. Its only metal, plastic and textile. You can overcome it. Study what you are working with and get back with a detailed report of what you have.
 

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Well, just for the hell of it I did a compression test. Only 90psi. I wonder when the needle in the carb stuck if it bent the valves. I tried to start it the next day not knowing the cylinder was full of gas. Now what? Guess I will start with removing the head. Any suggestions. The bike ran fine until I had that problem.
 

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Everything on the bike is stock. The air filter is from Kawasaki and brand new. I got the bike from a friend of mine. He just put it in his shed 15 years ago and never rode it again. I was running fine when he put it away. Only has 7000 miles on it. No modifications.
 

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Hold up on the wrench there Sparky!


That compression test is interesting. Keep in mind that your bike has a Kawasaki Automatic Compression Release (KACR) that automatically lifts exhaust valves at cranking rpm to make starting easy and eliminate the need for a manual compression release. This will effect a compression reading. The "CR" in KACR stands for "compression release! If you are showing 90, thats enough for the engine to fire. I've rebuilt old hit and miss engines that had a whoppin' 35 PSI. Model T's pumped out right at 50PSI on a good strong running one. KLR 650's aren't all that far removed from Model T's ya know. If you understand one, you can fix the other.

The condition that the petcock caused, flooding the engine crankcase with gasoline, is called hydolock. Typically, what gets damaged is the weakest link that is directly in line for the forces brought about from hydrolock, and that would be the piston connecting rod. this condition was responsible for the death and demise of more Harley Davidson's than wrecks or ex-wives. I haven't encountered bent valves from hydolock. Yet.
 

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Well, just for the hell of it I did a compression test. Only 90psi. I wonder when the needle in the carb stuck if it bent the valves. I tried to start it the next day not knowing the cylinder was full of gas. Now what? Guess I will start with removing the head. Any suggestions. The bike ran fine until I had that problem.

Did you drain out the crankcase after the hydro lock? If the cylinder was full of gas the crankcase is too.

It's hard to get a good compression check because of the auto decomp on the exhaust valve like vatrader is saying. Yea you can bend a valve if you keep cranking the starter. Pull the plug and crank the motor, put a towel over it first! Change the oil and try to start it.

Sitting for 15 years? I would clean out the tank really well maybe even use a sealer.
 

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Discussion Starter #15
That's good news. I guess back to fuel flow and carb stuff. Thanks Again. I will go through my service manual to see if I missed something.
 

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That's good news. I guess back to fuel flow and carb stuff. Thanks Again. I will go through my service manual to see if I missed something.
To me, the information about the air filter being stock and the exhaust being stock is good news. No need to stab in the dark hoping to find a air / fuel balance for unknown contributing players. Sometimes that is a wildly moving target to hit if all parts are known!

Can you describe how you went about the .22 mod? How many washers under the needle? What size hole was drilled in the slide? How many turns out on the air / fuel mix screw?

And very important.....what condition is the diaphragm in on the top of the slide, and how did it go re-assembling the slide? The last condition you described makes think you might have some diaphragm issues...not seated right, tore, hole rotted through. Might want to pop that back out and take a look.
 
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