I just bought a 1990 zx7 that was sitting for about 1 1/2 yrs and It would not even start when I got it. I pulled apart the carbs and cleaned the jets and it started easily but it is running pretty rough. I would say that it is missing and has bad throttle response. I would like to know where I should start looking and if anybody has some ideas I might not be thinking about. Any help would be greatly appreciated. Check for air leaks? check for synchronization? check air/fuel mixture? or maybe I should clean some more parts?[8D]

 

New plugs.

 

I put in new plugs and I have spark to all unless maybe I fouled one out

 

clean, clean, and clean your carbs. My GF's dad bought an '02 Yama FZ1 from a guy who let it sit for 6 months and it ran like crap, if it would run. He took it to the local dealer and had them clean the carbs twice and it then ran better, but not the best. After the first cleaning, it would idle fine, take off fine and then start to lug the engine after second gear. His solution was to just drive it and burn it all out, then clean carbs for the second time after which it acts as it does now. It smells a little rich still and there is an occasional "hiccup" at idle, even after it's warmed up. My suggestion for him now is to change the fuel filter, although he has yet to do so.

After cleaning the carbs very thouroghly, I recommend checking the tank to see if any of the gas left deposits in there. I would definitely replace the fuel filter as well. If you can get it to run though use it, cause the burn it off method seemed to work ok.

If you discover some other method in your repair process, please let me know so I can pass it along to the future dad-in-law! we've been scratchin heads on this for a while.

 

make sure the carbs are synched maybe? unless it was properly stored you may want to check the airbox and exhaust for anything that might have crawled in there.

 

Valve adjustment... a necessity for that particular motor.

 

SOME NEW INFO FOR YA, WHEN I RUN THE BIKE WITH NO AIR BOX ON AND COVER ONE OF THE CARBS WITH MY HAND IT SEEMS TO RUN BETTER. AFTER I ADJUSTED THE PILOT SCREWS!!! tHAT FUEL FILTER WILL BE NEXT!!!

 

not as if ya haven't figured it out from what ya just said, but I believe that an air filter cleaning and a carb synch are in order w/ that knowledge at hand.

 

It sounds like your on the right track. I cannot stress to you enough about cleaning those carbs tho. Make sure the inlet boots are not cracked either. With age the rubber will dry up and crack. Also, make sure the tank does not have rust in it. Then, if it doesnt have one already, put a filter on the fuel line that goes from the petcock to the carbs.

 

UPDATE
The bike is running well now except for it will not idle without the choke. I have cleaned the carbs,new fuel filter, cleaned the tank, new plugs ( twice),adjusted the air/fuel screws, and prayed a lot. I think the problem is now in the (slow) jets because of the idle issueand here is why I think that.
When I was cleaning the carbs for the 4th time I tried to take out the slow jets and the brass broke off the screw and they would not come out or loosen. (oops) I would like to know if this seems like a logical explanation and does anybody know of a tool that will work on stripped standard screws that small