Small engine trouble

[JasonW]

Figured I’d post this here.

I have a pressure washer that’s recently started giving me trouble and wanted to see if anyone has any recommendations.

It’s a Generac 196cc pressure washer that has stated to shut off right after starting, usuall around 10-15 seconds after starting. Doesn’t matter if the wand is pressed or not. This model does not have a throttle.

I can keep it going by moving by closing the choke then opening it back. After it has ran 3-5 minutes it will stay running like normal. So it only does it cold(cold is relative as the issue started during the summer).

Things I have tried,
Problem still happens with the gas cap removed.
Air filter is good
Spark plug is good
Dissembled/cleaned the carb(spotless inside, no trash found)
Checked fuel like for obstruction.
Adjusted the coil clearance.
Ran it with a spark tester in place to verify it’s not losing spark while running.


Ran it today and messing with the choke about 3 times it kept running for over an hour I was using it without a hiccup.
It seems fuel related due to operational the choke to keep it going, although when it dies it’s like the on/off switch is switched. Have not checked the valves.

The pressure washer is almost 8 years old and always stored inside. Has always started on the 2nd pull if not the 1st pull.

Super long post but I try to cover everything at one go.

TLDR pressure washer shuts off randomly when cold, after 3-5 mins runs like normal.

 

[whatsupdoc]

"Dissembled/cleaned the carb "
Did you clean the main jet?

 

[JasonW]

"Dissembled/cleaned the carb "
Did you clean the main jet?

Yes I did.

 

[NCL4701]

Sounds like you’ve eliminated most of the usual suspects.

I’ve seen a handful of situations where the interior surface of the fuel line starts to degrade and release very tiny particles into the fuel as it flows to the carb. They can be so tiny they’ll flush through the jet but the engine may stumble or require some choke as they go through. Chances are they’re not big enough to see with the naked eye when it first starts. Usually has some relation to ethanol in gas, but not always. 8 years old… wouldn’t exactly be surprising.

I would change the fuel line. All of it. If it has a fuel filter, I’d change that, too.

I’d also drain all the gas out of the tank into a clear glass container like a big old pickle jar, let it settle overnight, and check it for sediment/dirt. If you see any sediment, the tank will need flushing, While the tank is empty, look in it to make sure there’s no junk/trash in it that could be intermittently blocking the outlet. Not incredibly common, but seen it a few times.

 

[Workerbee]

How good are you at cleaning carburetors? Not a snide remark, but Ive seen lots of DIY,ers that don’t really know what to look for. You very well be proficient but most aren’t. Did you remove the welch plugs so you could verify all the passages are clear? The tiny ports that feed fuel into the venturi as the throttle plates open can be plugged pretty easily. If you don’t care to pull and replace the welch plugs to check those ports, at least run a bread wrapper twisty into each hole. Then see how it runs.