[notacop]

Hello!

My buddy picked up a 1980 KZ250 LTD from his neighbor. He told me that it only ran on choke. It wasnt running when he dropped it off. Long story short, It has an aftermarket china carb for a klx300 Bayou. I cannot get this thing to run for the life of me. Its got spark, though a little weak it would seem. It sounds like it almost starts but wont fully fire. I have a few questions!

1. Does anyone know if theres another carb thats oem i can run. Ive only found 1 stock carb on ebay and its more than the bike

2. Does anyone know the valve specs?

3. Does anyone have a pdf file of the service manual?

I appreciate your time!

Thank you?

 

[WFO-KZ]

Only running on choke indicates either a vacuum leak or plugged jets in the carb.

Service manuals are protected by copywrite so links or sharing is not allowed on this site.
You can often find manuals on Ebay or from resellers.

 

[notacop]

Only running on choke indicates either a vacuum leak or plugged jets in the carb.

Service manuals are protected by copywrite so links or sharing is not allowed on this site.
You can often find manuals on Ebay or from resellers.

Yes, normally the case. However carb has been gone through twice, all passages are clear. Looks to be flooding out and will not start. I have a feeling its to do with the aftermarket carb. i dont believe that the bike was running prior to me looking at it, due to a bunch of disconnected electronics.

 

[WFO-KZ]

You may be correct that the aftermarket carb is to blame.
Have you tried squirting some Quick Start into the airbox?
What is the compression like?

 

[1981GPZ550]

Step 1... Turn the fuel off at the petcock...remove the spark plug and kick the engine thru at leas a dozen times... put four or five drops of raw fuel in thru the spark plug hole...install a new spark plug, NOT a cleaned plug but a new one...Open the throttle about half way and attempt a start. If ignition timing and strength is ballpark close and compression is also ballpark close the engine will start and run for several revelations. If it does you can go directly to the carb. Unless that aftermarket carb was designed for your particular model you are likely to have issues even if it does start. You need to be aware and consider venturi size, main jet, pilot jet, needle jet, jet needle ( yes they are two different components) slide cutaway and jet needle clip position. Kawasaki's rotary valve engines were for that era superior to piston port designs but like every engineering choice there is always a downside. The carb chamber cap, the rubber cable seal from the carb chamber and the numerous connections to the air box all tended to allow some debris to enter the air intake system. This debris would over time damage the leading edge of the rotary valve and its adjacent rotary valve cover plate. If the engine does not start with the above procedure you will need to check compression, ignition timing and rotary valve health. For the rotary valve remove the carb and slowly rotate the engine until you see the leading edge of the valve appear, inspect the leading edge, some small imperfections are normal. push on the valve to verify it is securely attached to the crank. NEVER put your finger in there as you rotate the engine it is surprisingly easy to seriously hurt your finger. Finally if all else fails and this is a very long shot but I have actually seen it done and with these older machines and all the hands they have passed thru who knows, you will need to verify base gasket suitability. Make sure that if a previous owner made their own base gasket that they cut out the transfer ports.