Starts fine, idles well, bogs down when turning on PTO.

bobknowverylittle · Aug 19, 2025

I had been told that. Thanks again, I will look up manuals to see if i can get one,

bobknowverylittle · Aug 19, 2025

Star Tech, just discovered something strange, there is no accumulation of fuel in new filter. Put gas in other side tank, still same problem. Engine still starts no problem and idles fine. When i full throttle in neutral MIL light comes on for a short period and goes off. When i turn the key on pump runs for a couple of seconds, then stops running. It seems strange that the filter is not full of fuel, correct? Blew air in tank inlet hose and it definitely goes through tank.

Tiger Small Engine · Wednesday at 6:43 AM

bobknowverylittle said:
Star Tech, just discovered something strange, there is no accumulation of fuel in new filter. Put gas in other side tank, still same problem. Engine still starts no problem and idles fine. When i full throttle in neutral MIL light comes on for a short period and goes off. When i turn the key on pump runs for a couple of seconds, then stops running. It seems strange that the filter is not full of fuel, correct? Blew air in tank inlet hose and it definitely goes through tank.

Fuel filters don’t always fill up with fuel. Make sure fuel tank vent and or gas cap is venting properly.

bobknowverylittle · Wednesday at 11:04 AM

Will check venting tubes and caps, seems odd both tanks would be doing same, as one has never been used. Thanks.

Savage3 · Saturday at 9:23 AM

bobknowverylittle said:
Star Tech, just discovered something strange, there is no accumulation of fuel in new filter. Put gas in other side tank, still same problem. Engine still starts no problem and idles fine. When i full throttle in neutral MIL light comes on for a short period and goes off. When i turn the key on pump runs for a couple of seconds, then stops running. It seems strange that the filter is not full of fuel, correct? Blew air in tank inlet hose and it definitely goes through tank.

bobknowverylittle said:
Will check venting tubes and caps, seems odd both tanks would be doing same, as one has never been used. Thanks.

I would check the coils, sounds like a coil problem to me. Generally speaking, your symptom as described usually indicates a faulty coil.
The engine starts and runs fine. As soon as you start pto or try running up a hill or place the engine under load the engine will bog.

Usually it is only one coil that fails, the engine runs fine on the other coil until under load.

Oddjob · Saturday at 9:59 AM

One way to tell if you have only one cylinder working is to start it up and spray water on the mufflers. If you have a failing coil, one side will be a lot hotter than the other and will instantly vaporize the water.

RevB · Saturday at 11:09 AM

bobknowverylittle said:
Snapper Pro S200xt, 49E877 vanguard engine EFI system. As mentioned, engine bogs down when turning on the PTO. Just started doing that two cuts ago. Turned off engine to check for debris and or bad pulley, they were fine. Started engine again and problem went away, cut grass. Same thing happen again following week, again stop and restarted engine and all worked fine. This week problem has come back and is not going away as before. Plugs have only 28 hrs. , all pulleys were not hot to the touch. Any suggestions on what to check? M.I.L. comes on and then off again, just not getting full throttle when PTO engaged.

3k RPM or more before engagement. How do you define "full throttle" with PTO engaged...

bobknowverylittle · Sunday at 5:22 PM

Excellent idea, simple, smart and much experienced. Main reason i joined this forum. Thanks.

bobknowverylittle · Sunday at 5:28 PM

Thanks to all who responded! It is definingly running on one cylinder. It was hard to tell with it working on and off. But now it is not and easier to diagnose,

Oddjob · Sunday at 8:52 PM

So now swap sparkplugs and see if the good cylinder has switched sides. If so, you have a bad plug. If not, most likely a bad coil.

Starts fine, idles well, bogs down when turning on PTO.

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