i still say it's a spark issue. but ya never know.

HR

 

I didn't say I disagreed with you, just that he claims it runs ok at higher rpms. Probably would be a good idea to ask him what it maxs out at miles per hour wise. Because ignition systems dont just fix themselves at 1/3 or 1/2 throttle, that's when the usually crap out as you really start to work them. If his max speed is low then the lazy cylinder is just being covered up by the faster firing rate.

 

Actually I appreciate all the direction I am getting from everyone. Most often my wrenching is a result of deductive reasoning and applying what I learn from you all. I really do thank everyone who has taken the time to offer suggestions.
To answer some good questions posed to me:

Yes I checked spark on the rear cylinder using old front and rear plugs and both sparked strong. They were CR9E's. I checked spark at rear and front cylinder with new CR7E plugs and both were good snappy sparks.

Idle jet is a 40 on the rear. Didn't check the front.

I have pulled the float bowl 4 times and sprayed cleaner all through. Even pulled the idle jet and made sure it was free of gum and debris. The rear carb looks to be very clean. Float needle is also clean with no deposits and rubber tip looks good with no cracks or depressioins.

I have not looked real hard for a choke splitter yet as I have been under assumption only front carb had enrichener. The cable clearly goes to front carb but I did not notice it on rear one perhaps because I was not looking for it. Will take a better look.

Thank you again everyone. You all have helped me sort this out one possibility at a time.

Alan

 

PS. Checked again two nights ago. Float is intact with no cracks or fuel caught in them.

Alan

 

actually, bear, sammydogs is right the choke is split and goes to both carbs.

 

If that is actually the case the the choke (actually an enrichener) could be hanging up on the rear carb.

 

If you can screw in the rear pilot all the way and it makes no difference, fuel is getting to the rear cylinder from some where. i agree with Bear that ignition systems tend to crap out the higher the RPM because they have to work harder. So spark should not be the issue. So the question becomes where is the fuel coming from. Assuming the choke (enrichment) isn't hanging up, then there are two possibilities; a fault in the manufacturing of the carb, like a hole larger than it's suppose to be, or one where there shouldn't be, or a plug missing, or something like that. The probablity of this is very small, but Alan is grasping at straws here. A second, and more likely possibility is perhaps a scratch or scar or burr on the needle seat. The seat can't be seen very well that's for sure, and blowing to clean it out won't help. A micro bur could make all the difference. You've switched the plugs so a bad plug, remote as it is, has been ruled out. I assume you've checked the plug wire and connection and so on. Again grasping, and spark problems just don't seem right in this case. If it were me on my 650 I'd propose to my dealer we swap a known good rear carb for the one on my machine temporarily just to see if the carb is the problem. If so, he can get you a new carb. If not you know to look elsewhere. Okay, my brain is empty now, I've dumped my load to this perplexing problem. Like others, however, I do what to know what you finally find out.

 

grasping at straws is a nice way of saying I'm frustrated as hell. I don't suspect spark becuase the plug sparks strong when I pull it out and lay it on the case and watch. 1/3 to full throttle is smooth and 50 mph is hit quickly and with speed left over. Partial throttle like 1/4 or less my quad sputters. I smelled my motor oil last night and it smells of unburned fuel. I looked for a enrichener cable going to my rear carb and I can't find it. Do I have to pull the airbox to see it? I sure can't see it from the sides. I would take to my dealer but I have met all the techs that work for the local dealer and they are not very experienced or trained. I'm thinking about taking it to a Kawasaki dealer if I have too. I live in the Phoenix area. Does anyone know of a good mechanic for the AC 650? A bur on the float valve seat would explain the richness for sure. Think I will get a fiver optic light and mirror and give it a look. Come to think about it I think it has always ran like this since the day I bought it but only now started looking into it.

Thanks,
Alan

 

I have 2 04 650's had same prob on wifes bike rear cable where goes into carb stuck causing rich cond. I pulled carbs took both cables out of carbs cleaned all the crap out of springs lubed with waterproof grease reinstalled never another prob. What I did where spliter is for cable I took apart that left me with 2 small cables that go into carbs when I need to choke I reach under & pull cables by hand very easy. Don't know if 05 plastics will allow you to get hand in there. I got sick of replacing choke levers & lubing cable every 3 months. My rear plug was black until i did this. These are just plunger like cables that have a spring. It sounds like you hav'ent pulled carbs off bike. If thats the case pull them off it will make a lot more sence to you very basic setup. I went crazy thinking it was electrical problem.

 

You can get at the choke splitter from the front inner left fender well. You remove the mud guard/inner fender well, you now see the spark plug and front cylinder. The choke cable runs down the handle bar and beside the front cylinder head. Just have someone tug on the choke cable from the handlebar and you will see it move down below. If I remeber correctly you twist the ends and it comes appart. This is a real pain in the but to get it back together due to the way the plastics are on the AC. It woul be much eisier to remove th whole front plastics but that is a pain too. It might be eisier to remove the airbox and carb to verify the cable is not stuck on the carb side first.