Kawasaki FC420V dies after 25-30 minutes

[johnb143]

Hmmm...lots of Kawasaki threads today.

I have a FC420V on an Encore 48" belt drive WB. After 25-30 minutes of use mowing at WOT/3600RPM, the engine will start to hesitate/bog down. RPMs drop to the 2400-2600 range, and if you don't immediately remove load from the engine (disengage blades & transmission), the engine will die. If load is removed, engine will struggle back to 3500-3600RPM, and then bog again when load is reapplied. If you allow the engine to die, it will restart on the first pull (with choke), and then repeat the bog/die behavior as soon as you reengage load.

Yesterday I went through this cycle with it, trying to get it to restart and run, for about a half hour after it started acting up. Eventually just parked it. Pulled it out again today, same behavior after the 25-30 minutes of use. Let it sit for about 30-40 minutes while I finished up with a 21" mower and trimmer, then started it up again. Ran for about 10 minutes and then had the same behavior.

I'm thinking it's got to be something thermal as the engine heats up. Anyone want to point me towards a direction...carb or coil/ignitor? Fuel appears to be consistently getting to the engine, based on the fact that it always will restart on the first pull, and the clear fuel filter is full.

Engine is a FC420V-FS15, E/N FC420VD94123.

Thanks in advance for ideas.

[MowerMedic77]

Does not sound spark related usually they will not start back after dying, when it bogs can you pull the choke and keep it running? If so you may still have a fuel issue always check from the inside of the tank through the fuel lines to the carb then clean out the main jet in the carb. Also make sure your gas cap is venting properly. Hope this helps:)

[viper00085]

I agree with the Medic on this one, It is easy to check if its spark related with an inline tester but i dont think it is.

I have always had problems with encores and fuel flow stopping, specially on the encores with the quik disconnect tanks. I have always had to get creative with fuel line routing and what fuel filter to keep it flowing properly, even had to put a pulse fuel pump on one unit to fix the issue. and it was doing just like yours, about 20-30 mins start to bog down.

[johnb143]

Thanks guys. I'll take a look at the carb and change out the fuel filter next week.

Viper - yep, I'm well familiar with the Encore "creative fuel line routing" dance. Can't for the life of me figure out why they put the tank outlet on the opposite side from the engine fuel inlet. My tank is currently riding backwards to get rid of some of the twists and turns.

[johnb143]

Update...I replaced the fuel filter (did not change/adjust anything else), and now I have fuel pouring from the overflow tube connected to the top of the carb. Any tips on how to slow down the fuel flow/did I put too "loose" of a new filter on?

[Jim@MilkyWay]

Update... I have fuel pouring from the overflow tube connected to the top of the carb....
Filter can not cause this. Sounds like you picked up a piece of trash and it stopped, at the needle valve in carb.
Your fuel is not shutting off as a reslut...Err, Uhmm result.
Remove bowl and float assy. then access the needle/fuel cut off and inspect it. Either the needle or seat is damaged, (not likely) or a piece of trash is trapped in the jet/seat thereby preventing fuel shut off.

[Jim@MilkyWay]

Filter can not cause this. Sounds like you picked up a piece of trash and it stopped, at the needle valve in carb.
Your fuel is not shutting off as a reslut...Err, Uhmm result.
Remove bowl and float assy. then access the needle/fuel cut off and inspect it. Either the needle or seat is damaged, (not likely) or a piece of trash is trapped in the jet/seat thereby preventing fuel shut off.
Forgot sumpin'
If you literally did not crack open the carb, then it is complete coincidence that it started leaking when you changed the filter.
I got the impression that this engine has not been sitting idle, that is, not used for a time.
Solve the fuel issue first, as engine can not function properly if fuel is flooding into it.
It is possible to have more than one problem; hopefully that is not the case.

[johnb143]

Yep, looks like it was a two-for-one. I hadn't done anything with the carb, but the overflow started as soon as the fuel filter was changed. I dropped the bowl on the carb and there was some garbage sticking to the side of the float, causing the float to stick. So I cleaned that up, put the bowl back on, and all is well...just mowed the whole property without any of the bogging down issues that were the origin of this thread. So I'm guessing maybe the increased fuel pressure from having a good fuel filter moved some junk from the bottom of the carb bowl up to where it could cause issues. Anyway, learned something new, it appears to be fixed, and have to say a word of thanks for the fast responses from the forum.

[J&R Landscaping]

Did you check your intake gaskets and air cleaner? Sounds like you have an open area somewhere on the enigne. Obviously if you allow dirt to continually get into the engine, you can cause major damage to the engine.

[johnb143]

Yep, good reminder. Replacing the air filter and wrap as well.

[notoriousDUG]

Did you check your intake gaskets and air cleaner? Sounds like you have an open area somewhere on the enigne. Obviously if you allow dirt to continually get into the engine, you can cause major damage to the engine.


Huh?

He has junk in the float bowl of the carburator... that did not come from the air stream, it came from the fuel tank.

[Stevegotcrabgrass]

Huh?

He has junk in the float bowl of the carburator... that did not come from the air stream, it came from the fuel tank.

LOL...this is silly. What sits on top/side of a carb? An air cleaner assembly.
What is a carbs job? To mix fuel and air.

[DT Lawn Care]

LOL...this is silly. What sits on top/side of a carb? An air cleaner assembly.
What is a carbs job? To mix fuel and air.

You felt it necessary to criticize a minor comment from 4 years ago. If your name wasn't Steve I'd say you were a woman :laugh::laugh::laugh: jk jk

[Stevegotcrabgrass]

Wow that thread is that old....?? Didn't realize...If he was a minor then, he probably isn't now.

[DT Lawn Care]

Wow that thread is that old....?? Didn't realize...If he was a minor then, he probably isn't now.

What???? :hammerhead::hammerhead::hammerhead:

[Stevegotcrabgrass]

What???? :hammerhead::hammerhead::hammerhead:

I thought you said a minor's comment (as a person under 18 years of age) not a minor comment....

So in closing...this thread is very old. It was a minor comment. Not a comment made by a minor. :hammerhead::hammerhead::dizzy::waving:

[bhos]

Thanks LS... same engine, same circumstances, same problem. The problem is the fuel line is old, bits of it came off inside when installing the new fuel filter and went straight into the carb. Replace the fuel line (at least from the filter to carb) if this happens to you. Also, remember to pull the spark plug to drain the fuel from the cylinder prior to attempting to start it, it's likely full of fuel too.