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Trying to help a buddy get his Turf Tiger running. Model STT61A-27KA. Liquid cooled 27 hp Kawi engine.

When I arrived, it would not start at all. He replaced the fuel solenoid the day before. Didn't help. The starter would click but not turn the engine over. I pulled a plug and the cylinder was full of fuel. Excess fuel virtually hydrolocking the engine. I evacuated the cylinders of excess fuel, unplugged the fuel pump, and she fired right up. So I figure it's a carb issue....

I removed the carb and cleaned and checked to my ability. Held the float valve in the closed position while apart and blew threw the fuel barb and couldn't blow air past the valve. Open the float/valve and I can blow air. Seems normal. Soaked carb in carb cleaner for about 10 minutes, reassembled and gave it a go.

Same issue. Flooding the cylinders with fuel. When it does start it runs VERY rich. Engine sounds as though it's missing and won't clean out/increase RPM. If I unplug the fuel pump while running, it will clean out and run as it should, but as soon as I plug the pump back in, it starts bogging. I can sit there and plug/unplug the fuel pump and keep the engine running like it should. For some reason the thing is just loading up.

He is going to purchase a new carb but for almost $400 it just seems like a simple fix of the existing carb would be the solution.

Figured I'd ask here and see if anyone had any experience or suggestions.

Thanks in advance folks!

The carb float may no longer be buoyant, fuel shutoff solenoid may not be working, this is a horizontal crankshaft engine?
Possible leaking fuel pump diaphragm, could leak fuel into crankcase or depending where the pulse hose is connected, could leak into a valve cover and then into a cylinder.
Mad Mackie in CT

Mad Mackie said:

The carb float may no longer be buoyant, fuel shutoff solenoid may not be working, this is a horizontal crankshaft engine?
Possible leaking fuel pump diaphragm, could leak fuel into crankcase or depending where the pulse hose is connected, could leak into a valve cover and then into a cylinder.
Mad Mackie in CT

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Thank you Mad Mackie.

I inspected the float for cracks or internal fluid inside the float and didn't see anything. I did not, however, submerse it to see it if floated or filled and sank. I can try that.

Is there a way to test the fuel pump diaphragm? The pump runs continuously no matter what. If I key-on but do not attempt to start, you can hear the pump running. Is there some sort of way the pump knows when to trigger on/off or is it supposed to run non-stop regardless of fuel demand?

I'm uncertain of where or what a pulse hose is. Could you please elaborate?

Thank you again for your response.

Machine has an electric fuel pump, so it won't have a pulse type fuel pump. Fuel pump output pressure may be pushing the float needle and seat open due to a float that doesn't have sufficient buoyance to push the needle to stop fuel flow when the fuel level in the bowl rises up.

Mad Mackie said:

Machine has an electric fuel pump, so it won't have a pulse type fuel pump. Fuel pump output pressure may be pushing the float needle and seat open due to a float that doesn't have sufficient buoyance to push the needle to stop fuel flow when the fuel level in the bowl rises up.

Click to expand...

That really sounds like the issue doesn't it?

I can't think of anything else that would cause flooding like this.

Guess I'll just have him replace the float and needle. $40 is better than $400.

Thanks. I'll update as we progress.

BLK_03 said:

That really sounds like the issue doesn't it?

I can't think of anything else that would cause flooding like this.

Guess I'll just have him replace the float and needle. $40 is better than $400.

Thanks. I'll update as we progress.

Click to expand...

Any progress with this problem? I have the same issue, and first tried to replace the float, and when that didn't solve the problem, purchased a new carb. Still the same issue. Is there some sort of sensor in the electric fuel pump that shuts it off when it hits a preset pressure? I can see fuel pouring into the carb throat with the key on and the pump stays running.

Rwgagnon said:

Any progress with this problem? I have the same issue, and first tried to replace the float, and when that didn't solve the problem, purchased a new carb. Still the same issue. Is there some sort of sensor in the electric fuel pump that shuts it off when it hits a preset pressure? I can see fuel pouring into the carb throat with the key on and the pump stays running.

Click to expand...

He took it to a local shop.

They replaced the carb and fuel lines. Almost a grand later, it's running.

Sorry I don't have more info for you.

BLK_03 said:

He took it to a local shop.

They replaced the carb and fuel lines. Almost a grand later, it's running.

Sorry I don't have more info for you.

Click to expand...

That is what I was afraid of... I have also replaced the fuel pump, thinking that maybe it had a pressure sensor or regulator in it that had failed, but same problem with new pump. Maybe new carb has bad float valve, too, or maybe there is some adjustment that I need to make. Oh well, I will keep trying...

Dragging up this old thread just to mention what I've found.

I had the same issue with a FD750D and wanted to share my experiences. I had flooding, hard start/no start, fuel coming out the exhaust, and even hydrolocked it once while cranking. Turns out I had a plugged vent line from the carb bowl. I took the carb apart 3 times and checked the needle and float, primer pump, shutoff solenoid and still couldn't get it to run properly. I was about to order a carb like others have suggested but happen to try it without the vent hose on at it runs like a top now with no flooding. The needle and seat and float are working properly and can old back the 3PSI coming from the primer pump without flooding.

Hope this helps and saves someone a few hours of tinkering and $$$

The ole digital fuel injected or the direct fuel injected engines gives a lot of fits of this type of running issues. Very common.

Sounds like some owners should be doing some oil changes as well, get that diluted oil/gas out to be safe.