Dave,

When it starts to surge apply the choke SLOWLY and see if it smooths back out. If it does your problem is most likely fuel related (trash/water in carb) in which this repair would not be covered under the warranty.

If it doesn't smooth out then it could be ignition related which could be covered under the warranty.

 

I will try that as soon as I get the chance. When I replaced the plugs I got a solid 45 minutes of smooth running out of the machine. I forgot to mention this, maybe it can help eliminate some possibilities. I replaced the original NGKs with Champions, and I noticed a slight, barely noticeable drop in RPMs, likely due to the different plugs I believe, but the problems came back after that first 45 minutes with the new plugs.

 

Gotta bump this one up - need some help soon. thanks guys

 

did you try what rob said with the choke?

 

I did, and it worked one time, but it wouldn't do it again. I can't actually try anything on the mower until friday as I am away from home at school, so I'm just looking for ideas so I can go all out on it when I get home. I have six clean ups to do this weekend and would prefer to use the ferris, but I can use the toro if I must.

 

You did not post the spec # so I don't know which carburetor is on it, but check the carburetor vent tube if it is an externally vented carburetor. Most hang down & can get clogged with mud or dirt & not let the carburetor vent properly. It's an externally vented carburetor if there are two hose fittings on top of the carb. The larger one is for the fuel inlet & the smaller diameter is the carburetor vent.

 

I'll make sure to check that when I get home. I will probably clean the carb out on friday, and hope this solves all of my problems. I would post the #s but I am 1 hour away from my equipment, so it'll have to wait.

 

You should definitely check your valve clearances, pull the valve covers,
carefully, and you can reuse the old gaskets. Check your rocker arms/studs
for looseness, and check the clearances.
It is routine maintenence anyway, and costs nothing to check, and is
more than likely at least part of the problem.


If it is not, then you have spent nothing, and your valves are adjusted....


Fish

 

Dave -- Sounds like an interesting situation, please let us know what results you get from these suggestions !!

 

If you disassemble this carb completely, be aware that the right & left jets are different bore sizes. The # is stamped on the jet. Just remember which side they came from. I really don't think you will find any trash or debris in there when you take the bowl off. One other thing to check, if it has a fuel valve, make sure it is open. I have seen these things closing slightly for no apparent reason.

 

Thanks for all the suggestions, I will write em all down and go to it on Friday and report back as soon as I find the root of the problem.

 

You should definitely check your valve clearances, pull the valve covers,
carefully, and you can reuse the old gaskets. Check your rocker arms/studs
for looseness, and check the clearances.
It is routine maintenence anyway, and costs nothing to check, and is
more than likely at least part of the problem.

If it is not, then you have spent nothing, and your valves are adjusted....

Fish

It only has 120 hours on it. Kawasaki says every 300 hours. I would highly doubt this has anything to do with it unless it was not adjusted properly when Kawasaki put it together in which case it would be under warranty.

I would not recommend pulling your valve covers unless you are sure someone in your area has new gaskets just in case.

 

He purchased a demo a year ago, for a commercial application,
and it only has 120 hours...................
The dealerships I have worked at, usually have the hourmeters unhooked...........
If the valves are too tight, it would run fine until the valves warmed up .....
Maybe not the problem, but sure sounds like it might be.

If it costs nothing to check them, what is the harm?
OK, buy some new gaskets in advance.

Also, we are assuming you have ruled out a fuel tank venting problem.


Fish

 

I have that same engine on one of my mowers and if you do not change the fuel filter about every 100 hours it will do exactly what you are describing. Replace it and see. I would bet that will fix it. I switched to a similar sized Kohler fuel filter and do not have to change it as often.

 

It was the fuel filter, problem solved. Just to make sure i was making the right fix, i used the mower until it started acting up, then i replaced the filter and it was all better. Improved throttle response, higher rpms, and more power all from a simple filter. The amazing part is that none of the manuals that came with it say when to replace the filter. Although they mention replacing it when it is clogged, they don't say what problems a clogged filter would cause nor do they specify when to replace it based on hours. Oh well, problem solved, lesson learned. Thanks for all the excellent suggestions any way, your assistance was greatly appreciated.

 

It was the fuel filter, problem solved. Just to make sure i was making the right fix, i used the mower until it started acting up, then i replaced the filter and it was all better. Improved throttle response, higher rpms, and more power all from a simple filter. The amazing part is that none of the manuals that came with it say when to replace the filter. Although they mention replacing it when it is clogged, they don't say what problems a clogged filter would cause nor do they specify when to replace it based on hours. Oh well, problem solved, lesson learned. Thanks for all the excellent suggestions any way, your assistance was greatly appreciated.

:waving::waving::waving::waving:You are welcome.:waving::waving::waving::waving:

It may seem silly, but always start with the most obvious.

 

I have exactly the same problem, changed the fuel filter and fuel pump.... NOT FIXED

 

Start a new thread, this one is 16 years old

 

Pop the hose of the fuel filter on the tank side. Put your mouth on it and blow your guts out!! Fuel pick ups in both tanks get blocked! New inline fuel filter helps too. 2003 Cub 60 tank with a 25 FH721V. 1600 hours. Grass On! Wishing the wife would suck as hard as I blow!!