View Full Version : Kawasaki FH451V Nagging Problem

07-14-2007, 10:45 AM
My Gravely 34Z has a Kawasaki 15HP, FH451V engine. After around 20 minutes of operation it acts like it is not getting enough gas. Chocking it helps but only for a few seconds. It stalls. Changing from one fuel tank to the other does not help. Leaving the gas tank caps loose does not help. If I wait until it cools, around 15 minutes or so, it will start and run for another 15 or 20 minutes before stalling again.

Being mechanically challenged, the only thing I could think to do was replace the fuel filter. It did not help. Any ideas what is going on?

07-14-2007, 01:07 PM
I would check both tanks for Debris(paper,leaves,plastic,etc.) if none found then I would check the T in the fuel line(if one present) and make sure nothing is lodged inside and also inspect all the fuel lines. Hope this helps:)

07-15-2007, 01:39 PM
Thanks for the input. I will do what you suggest.

It puzzles me why it might be dirt in the fuel area and not be caught by the filter. Also, why would a wait period of several minutes clear up the problem for another 15 minutes of operation? To answer my own question, I guess the dirt causing the stall could settle back out of the way until it gets stirred up again. I will start by checking between the filter and the T valve since the stall happens when using either tank.

07-15-2007, 03:29 PM
Just for giggles, Next time it shuts down pull the spark plug wire immediately and check for spark. You could have a coil heating up and breaking down.

07-15-2007, 04:25 PM
Thanks. I will do that.

07-23-2008, 08:29 PM
Mine also does this. I've replaced the fuel pump twice in the past and the problem cleared up. This time, it's not.

I replaced the main fuel line going to the fuel filter today to see if that helps. Mine stalls, then re-starts almost right away and runs fine for another five minutes or so before stalling again.

It's a real pain in the butt. If you figure it out, please let me know. I may have to bite the bullet and take mine in to the shop.

07-23-2008, 08:38 PM
Here is the thread on my machine.


07-24-2008, 08:08 AM
Solved the problem by re-routing the fuel line away from engine heat; a vapor lock problem.

07-24-2008, 11:03 PM
I'm going to try that on my machine. Thanks.

Let me know if it keeps working. Mine ran fine for an entire day, then started acting up again.

07-25-2008, 03:55 PM
It has been working fine now for about 15 hours in the Florida heat. I can't figure why it worked for about 60 hours after purchase with no problems, then became a problem because gas lines were too close to the hot engine. Perhaps the engine is running hotter than it did when new. It looks like my problem is over with the relocation of the gas lines away from engine heat. Will keep my fingers crossed.

Good luck to you.

07-25-2008, 08:55 PM
I re-routed my fuel line, and it worked fine today until I ran one tank out of gas. After switching tanks it acted up for a while, then ran fine again. I think the Kawaski has a hard time drawing fuel out of the tanks on this machine.

Like you, I had this problem after about 50 hours, then it went away again until I hit the 500-hour mark.

There doesn't seem to be any reason behind it - it just happens.

I will keep you posted as to whether it stays working.

Thanks again for the tip.

10-21-2010, 12:50 AM
I recently had to fix a similar problem, I found out that the carburetor was having some kind of sticky sludge inside. I tried to clean it but the parts are so small that seem almost impossible to removed. Therefore, a had to buy a new carburetor for it. here is the schematic for your carburetor and the web side where to find the parts you need. http://www.partstree.com/parts/?lc=kawasaki_engines&mn=FH451V-AS07+4+Stroke+Engine+FH451V&dn=99907-20500080