Briggs Power Washer

[lefty]

Seems like it was stuck. After holding it open with a screwdriver, it now seems to work properly, at least warm.

Could I have jammed it while taking the carb off and putting pressure on the mechanism at the muffler end through the linage? Not sure how the internals of those types of chokes works. Wondering if I should replace it or just consider it fixed. Seems to work fine now. Explains a lot now that I think about it. Apologies to skywatcher who actually told me to pay close attention to those butterflies.

[lefty]

So that seems to be the issue. Once I put a load on it, the choke closes for some reason. I let it cool down and started it again with the same results. When I put it under load, the choke closes up. If I hold the choke open manually, everything seems to run fine.

I would think that a faulty choke would be faulty no matter what. Trying to figure out why it may close only when under load. Makes me think it's something with the linkage not being correctly connected. Since I'm thinking, the governor pressure may be putting pressure on it since that's all interlinked ontop the carb. Am I thinking correctly? Should I be chasing that as a problem or just replacing the choke?

[lefty]

I think I've gotten to the bottom of this but need some guidance. How long should it take the autochoke thermostat to fully open the choke?

Currently, the machine needs anywhere from 3-5 minutes to warm up to the point where it has the choke fully open. It's about 90 degrees here right now and the machine is outside. I started it and after about a minute, the arm from the thermostat was still not moved over enough to hold the choke open. So when I put it under load, it vibrates closed and flaps around, which was creating my dropping rpm symptom. If I hold it open with a screw driver, it would run properly.

It appears that when the machine is not under load, the governor is pushing the throttle plate closed, which is holding the choke open. But as it comes under load, the governor pushes on the throttle, releasing pressure on the choke alowing it to close. Without the pressure from the linkage of the thermastat choke, the choke plate flaps around, forcing the RPM down.

After almost 5 minutes, the thermostat had finally warmed up and moved enough to prevent the choke from closing when it came under load.

This is a lot longer than I'm used to seeing. From what I've been able to find, the failure on these seems to result from the choke sticking open, not closed.

I'm thinking of replacing this but I can't find anything on how long the auto choke should take fully warm up and open the choke. Is it normal to have to let these warm up for that long. If so, I guess there's nothing wrong with this and I've been wasting everyone's time. Sorry about that.