kz550 carb problem

The carbs were rebuilt on this bike 2 years ago and it has not been used very much, although not entirely neglected in that time. When I left the bike in care of my significant other (always a bad idea) the bike started easily, made no primary chain rattle while cold or idleing low, and did not stutter on low end acceleration. It takes forever to warm up because you cannot set the choke and walk away. You must constantly feather the throttle to keep it running and when the engine wants to stall whenever you try to take off. There is also some stuttering on hard acceleration.

The bike is in good condition with fairly low mileage (15k) and ran beautifully before being ignored for 6 months. It is stock except for a properly jetted 4 to 1 exhaust. Now it runs like shit. What could have happened to make the bike run so poorly in 6 months time? I have run half a bottle of B-12 chemtool through the tank and added fresh gasoline with no change, and stranded myself while killing the battery due to hard starting.

Is this a simple case of sediment blocking something in the carburetor? As you can tell, I like to ride more than wrench and I have never worked on bike carbs before. I switched back to this bike despite the problems in an attempt to kick her in the guts and run the problems out. Despite freezing outside I still try to ride to work but I'm only a few hours away from picking up my Honda and returning the Kaw, and I hate to let these issues wait until spring.

Is there a simple diagnosis for this? I may be able to borrow space in someone elses garage to store the bike and remove the carbs if it's only requires minor invasive repair.

With the choke on you're forcing the carb system into a rich condition. Sounds like if it's not wanting to run on the choke, then you could have a fuel starvation, or a very bad vacuum leak.

1. Check vacuum fittings at the front of the carbs, and the line that goes to the petcock.

2. Check for vacuum leaks around the intake boots, between the head and the carbs.

3. Make sure the two bowl breather lines aren't capped, or restricting air. These are between carbs 1 and 2 and another between carbs 3 and 4.

Majority of the problems come from vacuum leaks from #1 and #2 above.

I'm sure WG will show up any time and give you more pointers, before you tear apart the carbs.

Post edited by: CoreyClough, at: 2007/12/03 15:50