Runs rough possible dead cylinder

[BlackburnD]

I ride a 2002 Kawasaki zr7s. It has been running really rough, and chugs under heavy acceleration. When I first start it I often have to crack the carbs wide open throttle. Earlier this year someone turned my valve to prime, and a half tank of fuel dumped into the engine. I changed the oil and filter, and has not been the same ever since. For awhile it seemed to be running rich blowing a Tom of white smoke from the exhaust. I assumed from everything just being soaked in fuel. I removed the carbs and pulled the bowls, and jets and the crabs look immaculate. I did not split the carbs. After a bit of riding the #4 cyclinder exhaust pipe is significantly less hot to the touch as the other three. I suspected plugs, and when I pulled the 3 & 4 plugs they look wet. The 1 & 2 plugs normal. I replaced them anyhow, and no change. I am getting spark to the plug, but unsure how strong voltage is at this point. Compression is good, it's getting fuel, so I still suspect spark. Maybe the 3 & 4 coil is going bad? Any ideals would help here. I gotta get this thing sold because I come back to the states soon, and its a German bike so it's gotta stay here. Thanks for any help.

[Kreylyn]

I ride a 2002 Kawasaki zr7s. It has been running really rough, and chugs under heavy acceleration. When I first start it I often have to crack the carbs wide open throttle. Earlier this year someone turned my valve to prime, and a half tank of fuel dumped into the engine. I changed the oil and filter, and has not been the same ever since. For awhile it seemed to be running rich blowing a Tom of white smoke from the exhaust. I assumed from everything just being soaked in fuel. I removed the carbs and pulled the bowls, and jets and the crabs look immaculate. I did not split the carbs. After a bit of riding the #4 cyclinder exhaust pipe is significantly less hot to the touch as the other three. I suspected plugs, and when I pulled the 3 & 4 plugs they look wet. The 1 & 2 plugs normal. I replaced them anyhow, and no change. I am getting spark to the plug, but unsure how strong voltage is at this point. Compression is good, it's getting fuel, so I still suspect spark. Maybe the 3 & 4 coil is going bad? Any ideals would help here. I gotta get this thing sold because I come back to the states soon, and its a German bike so it's gotta stay here. Thanks for any help.

I'd bet it's a float needle not sealing properly allowing fuel to flood the carb.

If you fill the carbs with fuel on prime for about 1 min, then remove and blow on the fuel line into the carbs... your probably gonna hear bubbles... and you should not be able to move air at all.

Pull the carbs again, bench test them until you can know for sure no fuel leaks past a needle.

Krey

[BlackburnD]

One float bowl could cause both cylinders to flood? I ask because both the 3 & 4 plugs were wet.

[Kreylyn]

One float bowl could cause both cylinders to flood? I ask because both the 3 & 4 plugs were wet.

causation and correlation....

You may have additional issues, you may have more than one float needle issue....

The symptoms you describe though are extremely indicative of at least one float needle not working right. If something causes one to have a problem, then it's possible that same issue can effect others. Rust, loose debris, etc...

Start simple, resolve at least 1 issue and test again. For sure, you have at least one float needle issue.

KRey

[BlackburnD]

Well I just filled the carbs and blew in as you directed and sure enough "gargle gargle"..... Guess ill be tearing the carbs apart again tomorrow. I hate carbs! Start throwing stones now folks cuz I'm buying a new Harley when I get back good ole USA....

[dgxser]

IF you buy a harley for the same amount you got in your Kat, you will decisively have at least a carb (if you get a bike at all) and it will need MUUCH more work than your Kat.

As to the carbs, think of it this way, 3 and 4 share the same fuel inlet hose. 1 and 2 share an inlet hose. If for some reason you got crap in the 3 4 hose, it would effect both carbs. Now since they get fed from one petcock on these bikes, it would seem it should effect all four, but, stranger things have happened.

Honestly, with the exception of all the hoses on the tank, pulling the carbs on the GSX600F I have is extremely easy!! You should try it on a Yamaha XJ1100 some time.

[BlackburnD]

Ya I'm not riding a Kat anymore. I bought this zr7 while here in Germany just have something to ride while here. The carbs aren't very to remove, I just don't like messing with carbs. And as far as the Harley goes it will certainly be a brand new bike which will be fuel injected.