Try removing the pipe from the fuel tank and check the flow, maybe there's a filter inside the tank that is slowing down the flow. Is there a fuel tap fitted? if so check for partial blockage.
Good luck Phil :usflag:

 

I replaced the pipe in the tank with a new one and that didn't help either.

 

Run a hose from the pump to a can and check for flow with the engine running. The only thing left is mayhaps a check valve in the line is clogged or stuck. If ya get gas out the pump, try removin the fuel solenoid and cleaning it .It does'nt take much to gum /block it.

 

Mike,

Put the unit under load where the rpm's drop then slowly apply the choke, If the rpm's come back up it sounds like a restriction in the main jet/circuit.

If that's the case the carb needs to be taken apart and all ports/jets and passages sprayed out with carb & choke cleaner followed by compressed air if available.

Good Luck

 

I just subscribed to this site because I am running in to the same problem on a 16hp Kaw (on a bobcat). I am getting a new fuel filter today and a new fuel pump. I got half of my lawn cut when it started acting up. it took it in to the garage and blew the lines and fuel filter out tried the choke thing and no inprovement. I got my dad over last night and it ran fine. It has always run great at slow speeds but when I rev it up and engage the blades it starts to slow down (half Idle). I am leaning towards a bad fuel pump.... any other ideas Help

 

Thanks for the info, I'll let you know what I find out tomorrow.

 

I tried pulling the choke when the rpms dropped but it didn't help much. Dealer mechanic said it could be the fuel selinoid, I looked for it but didn't see it. Must be on the backside of the carb? Any advice on cleaning the selinoid?

 

I dug in to mine today and took it apart. Wasent ad bad as i thought it was going to be. didnt find anything obvious. I did call the parts mand looking for a rebuild kit and there is not one avalable. he told me there are only 5 or 6 parts that can be replaced. he said another customer had the same type of issues and took the carb off and soaked it in carb cleaner for 2 days and replace all the parst he could and hehas not herd from him since. Must have fixed the issue.
I did spray carb cleaner everywhere I could and blew it all out but then it was time for Junior football practice so that project gets put on hold for now.....

 

Mike, did you get your mower fixed? Was it the carb or something else?

 

Read the thread "Please help,please help" Same problem. I've tried different fuel pumps on 19-25 hp Kawi's. No help. cleaned the vents. Also no help. Replaced the small Kawasaki fuel filters with larger Kohler filters. seemed to help. There are a lot of the same problem with Kawi's on this sight. One of the ones I worked on needed a fuel solenoid. The magnet was getting weak. After running for a half hour it will bog down or stahl. Teh pin was going back up into the jet, and when you turned the key back on, it would re-energize. This seems to be a common problem with the internally vented 2 bbl Kawi carbs. The old external vent did'nt do this. The dozen or so machiines I worked on NEVER lost spark, it was always fuel. When it stalls, pull the drain plug and see how much fuel is in the bowl. Kawi tech line says there is no problem. I say tell them to read this forum!!!!

 

sounds like water in your gas! keep using ethanol!

 

what I found wrong with mine has nothing to do with the carb or the fuel lines or filter. I did all the above! cleaned the carb replaced the fuel filter and it still had the same problem. I found that I had a bad coil!!!!!! it started bogging down after running it for a while so I removed both sparkplugs and compaired them against each other. One was as it should be dry and tannish and the other one was black and wet. This led me to a bad coil. when it is acting up try removing one of the wires from the spark plug and start it how does it run at idle? how does it run at full speed? then do it with the other one. I found that one of the sides wouldnt even start.

conclusion, I am replacing a coil.........

 

impulse line from the head/valve cover. what do you think runs the fuel pump? i mean, did you change that and put on new clamps? that might be the problem. i just had this happen to me on a 16 vanguard. rebuilt the carb, changed the pump, still running like poop. changed the impulse line, (as per the instructions, lol ;P,) and it worked fine. check that, as well as the other side where the pressure comes from. maybe there's poop in there, causing less pressure/vaccuum.