View Full Version : Kawasaki 19HP Hot Start Issue

06-17-2007, 12:49 PM
The hot start problem is on a Kawasaki 19HP FH601V with 192hrs. The motor will start fine if it is the first start of the day, if it has been given time to cool down in between mowing and if it is started right back up after shutdown for about 5 mins. When hot and sitting the motor will just crank and not catch. It seems that the mower is flooding but I havent been able to find the problem. I have replaced both coils, throughly cleaned the carb & replaced the needle valve, checked the float, replaced the spark plugs, checked the solenoid on bowl for power and while cranking, and finally checked and adjusted the valves at 185hrs. Intake valves were at .012 and exhaust valves .011. I adjusted all to .005. I just recently checked them again at 192hrs and noticed that the exhaust valves were both at .009. I just readjusted them again to .005. I believe that I have covered everything I could think of and the dealer as well. I think it definately is a fuel or valve related problem but I cannot pinpoint it. The dealer said it sounds as though the valves are seating fine and by ear they sound okay. Also, when cranked up to full throttle or PTO engaged a hesistation is noticed with some black smoke with these problems occuring all the time. Upon shutdown a nice backfire was present before both valve adjustments. Also, while looking into the carburetor while cranking excessive fuel is puddling towards the air cleaner and when opened up to full throttle from idle. Any advice as to this problem would be greatly appreciated. Thanks.

06-17-2007, 02:38 PM
What is the spec # for this engine?

06-17-2007, 02:57 PM
Fh601v- S29

06-17-2007, 03:26 PM
The fuel anti-backfire or fuel shut off soleniod on the bowl of your carb(should) have wires that plug into it. If it is this style which your spec says it has, I would remove it and check the end of the plunger It has and knurled metal plunger with a plastic tip installed on it. I had a unit in my shop that this plastic tip had actually slid up on the knurled shaft and would not always allow fuel into the main jet all the time along with some of the other issues you are describing. I ended up JB welding the Plastic tip onto the metal knurled shaft.

Just another thing you may want to check.

06-18-2007, 11:07 AM
Mowermedic77, I checked the fuel solenoid and all looks good. While I had it apart I epoxied the plastic tip onto the knurled end just as a prevent measure. Anything else to look for?

06-18-2007, 05:44 PM
What spark plug are you running and what is the gap set to?

06-18-2007, 08:19 PM
I had a similar problem with a 23 Kaw. I switched from champion to NGK sparkplugs, adjusted the valves, ran some seafoam through the crankcase and the fuel system and it cleared up.

06-18-2007, 10:07 PM
Currently I have Champion plugs installed however I normally use NGK BPR-4ES. I changed the plugs early in the year as part of a tune-up and recently changed them to Champions after this problem started to see if there was a difference and to date there is none. I will be swithing back to the NGK's soon as I feel they are a better plug in general. I dont recall what I set the gap to.

06-20-2007, 10:52 PM
I'm in the process of trying the seafoam idea. Maybe a few more hours of run time will provide some results.

11-29-2007, 09:55 PM
Well, figured that I'd update everyone on the issue in case anyone has the same problem. After countless hours tearing the motor down and numerous phone calls we found the problem. The timing gear on the crankshaft had spun about 45 degrees (******ed). The timing gear on these motors is pressed on and not keyed. What a disapointment! I am surprised it was even running. We found this by making a comparison to a like motor. The exhaust valve movement started 45 degrees later on my machine versus the comparison (about 4-5 gear timing gear teeth off). All in all, a new carburetor was replaced by dealer, I replaced valves, had valve seats re-cut, replaced camshaft(one lobe had an imperfection), replaced crankshaft, replaced coils, replaced piston rings, all seals, and gaskets. I can honestly say that it has more power than ever now! Hope this helps anyone with a similar issue.

12-14-2007, 06:48 PM
Its either the fuel shutoff that is attached to the carborator or the key switch that engages it. Bring the mower to a very quiet area and just turn the key one click and listen for a little ticking noise. If you can, get as close to the carborator to hear it better. If there is no click or ticking sound then it is probably the key switch. Wiggle the key when you turn it to the first click and see if you hear anything. If you don't then change the key switch, the fuel shutoff on the carb usually doesnt go bad that often, but it would be a good idea to make sure that the wires going to it are snugly attached.

12-15-2007, 09:36 AM
Did Kawasaki replace the engine?