DF20AEL Engine light on.

[Brew265]

Everything seemed fine but when operating about 3-4 min. It started running rough, engine light came on (no flashing) and there was a lot of tiller vibration.

We killed the engine, restarted and everything seemed normal again, but again 3 min and the same symptom every time.

If I leave it a few minutes running rough it comes good again for a few minutes only.

I get the same behaviour here at home. At low revs no issues, after a couple of minutes at higher revs the light comes on and it runs rough again

I have tested everything I know how to test and have done the following:

New fuel

new fuel filter (internal)

New fuel lines and bulb and tank

I don't see the bulb changing much (it does get a little softer but doesn't collapse) and have tried to pump it while it was happening but nothing changes
New plugs.
Anyone had this problem or know what it could be?

[Moonlighter]

You could have picked up a dirty load of fuel and the internal VSR screen filters could be partially blocked up. Causing starvation at higher revs. (That is a very good reason to fit an external Racor style fuel filter in the fuel line between engine and tank, should be mandatory on any efi engine IMO).

Its also possible it is overheating? Last time you serviced the water pump was ???

The best way of course to figure out what is going on is to connect the motor to the Suzuki SDS system. Fault codes will soon show what is happening and from there a knowledgeable dealer will be able to fix it.

[Brew265]

Going to a dealer Wednesday. If it was a fuel blockage it would not get to high revs but when first starts it goes high revs no problem for a few minutes. Water pump impellor was changed 60hrs ago and is pumping well. If there was a fault code wouldn't the red light flash some sequence? If I can tell the dealer what the issue could be it may save me some $$

[Moonlighter]

A partial fuel blockage will dedinitely show up under load, when the demand for fuel from the engine increases it will soon starve out.

There should be codes stored if the check engine light came on. I would expect that if the dealer can replicate the problem they should sort it out,.

[Solarman]

Are you reving above 3000 rpms? In neutral?

[Brew265]

Pulled out the thermostat today and it is covered in gunk and the internals are the same so I'm thinking that is the culprit. Motor will be cutting out from overheating due to the thermostat not opening. Will replace this and see if problem solved.

[Brew265]

It will not rev high in neutral.