View Full Version : Kaw Problems

04-06-2007, 09:55 PM
I have a customers commercial yahzoo walk behind with a 15hp kawasaki FH430V. It is surging badly. The plugs that it came in with were CJ-8's and I know they are wrong.What are the correct plugs. I replaced the carb with a new one and it didn't help at all. Both coils check out fine which leaves me to look for incorrect valve settings. I need the specs for intake and exhaust settings. Any suggestion on what else to look for would be helpful. When it runs we can engage the choke fully and no change in how it runs. The fuel pump is working, the fuel is new, the filter is new I have a set of J19lm's in it. It will start on the first pull but then will only surge, it will not idle ar even run at half throttle. Any help would be appreciated. Thanks.

04-06-2007, 10:30 PM
Since the choke has no effect then you must have a lean surge problem. Check the float level then move your way back to the fuel cell.

04-07-2007, 12:39 PM
Maybe you shoulld look at a Champion Catalog. J19LM's are definitely not the plug that should be in that engine.

CJ-8 is closer to right. I am not sure on the exact number that is called for but J19LM is definitely wrong.

Have you checked compression? Leakage? Does it keep surging if you hold the throttle shaft in a certain position or does it smooth out?

EDIT: Just checked. The correct plug for that engine is RCJ8Y or CJ8Y.

04-07-2007, 09:20 PM
Thanks, I'll replace the plugs with the proper ones. About the surging it will die if you try to hold the throttle stilll It will not idle. The throttle goes wide open, the engine revs up then dies back, revs up then dies back. Choking the engine does nothing. The manifold is not cracked. There has been other people in this engine so I don't know if everything is still there. Is there anything between the carb and the manifold other than a gasket? The valves are set at .003 intake and ,005 exhaust now.
I guess it is possible that the new carb is faulty. Any thoughts are appreciated.

Bill Kapaun
04-07-2007, 10:51 PM
A CJ8 & CJ8Y are totally different families of plugs, The "Y" means it's an extended tip plug.

I'm thinking Fuel Filter. The pump can be working great, but if the engine doesn't get enough fuel because of a clogged filter, I could see it exhibiting the problems you see.

Anytime "someone else" has worked on an engine makes one wonder why they didn't finish it. Could be a lot of reasons, with few of them "good".

04-08-2007, 01:08 AM
Like I said it's a lean surge. Check float level. Blow main jet out. Then work your way back to the fuel cell ie-filter,hose,trash in tank or bad cell vent. You have to try something then post back.

04-08-2007, 11:35 AM
sounds like u got gunked up main jet, pull and clean.