Briggs Power Washer

[lefty]

I got this in recently with the owner complaining about fuel leaking from the carburetor. I'm told it's "brand new", meaning a couple of seasons old with only limited use (two or three times). I went through the carb and it was very dirty with a sticky needle. It's a carb mounted flush to the engine so I wasn't surprised when I found no fuel in the oil. The tank fuel tank was empty when it got here.

So I cleaned up the carb, hooked it up to the water and it started the first pull....but there was a lot of white smoke and it ran rough for a bit before clearing out. I thought maybe the owner had tilted it while bringing it over and got some oil into the cylinder but they said they kept it level and I stuck a scope into the cylinder. It looked pretty clean.

Leak down was acceptable with nothing except some out the dip tube. But the numbers are good.

Started it again and again, had white smoke. It cleaned out after about 10 seconds but under load, it drastically looses power and RPMs drop. If I leave it under load for any amount of time, the white smoke starts again.

Head gasket?

Very few hours on it but that's the only thing I can think of. I didn't notice any valve leakage during the leak down.

Thanks

[lefty]

Sorry.

Just realized I forgot the information

Briggs: 020515
Serial 1020259701

Engine: 111P02-0114-F2
Code: 12090762

[RoyM]

Is the oil milky? I wonder if the pump seal is allowing water into the crankcase.

[lefty]

Negative. The oil level appears normal and the oil looks normal as well.

[lefty]

Flywheel key? I didn't even think of it with such low hours and not sure if that would be a symptom. Although flywheel key seems to be the root of many problems.

[lefty]

My smoke issue seems to have cleared up and I changed the oil. Owner said today he tipped the machine to the oil drain side when he saw it was leaking fuel. My guess is that maybe there was some oil in the cylindar that has cleared out. But if I stay on water nozzle, it wil drop in RPM's and eventually stall. Do I have a governor issue maybe?

I was a pretty simple hook up. I'm 1000 percent sure I hooked the carb back up correctly. It's auto choke and full throttle (no manual throttle). Is this a simple carb issue do you think? I'm at a loss. Runs fine now until you ask it to do it's thing. Then she craps out on me.

[Skywatcher]

Hi Lefty

Here are a few things to consider. If the flywheel key was sheared , the engine would either kick back when starting (flywheel slipped on crankshaft) or would be slow to attain full RPM if it got there at all (crankshaft slipped in flywheel). If the governor was hooked up incorrectly, the engine would probably race, then die down as soon as load is applied. What I understand you to say is the engine comes up to governed RPM on start-up, then gradually dies down when under load. This sounds to me more like a restricted main jet in the carburetor.

When the engine is running at governed RPM with no load, the throttle plate in the carburetor is probably only 15% to 20% open so the engine is drawing fuel through the pilot or idle circuit. Once a load is applied, the throttle plate opens up to 75% or so and starts drawing from the main or load circuit. If the main jet is restricted or insufficient fuel is getting into the carburetor to feed the engine under load, the engine will lose power and eventually die.

When you start, run and load the engine, do you see the throttle shaft moving in response to the increased load? Another simple check to perform is to loosen the fuel cap when running the washer under load to rule out the possibility of a fuel tank vacuum. Hope this gives you something to work with and please keep us posted,

Sky

[lefty]

Thank you. I will check both in the morning. Since the carb was such a mess, that sounds like a possible cause. I may not have done a good enough job on it. I'll post back tomorrow.

[lefty]

I checked those items and went through the carb again. Everything seems to be operating normally. The main jet is clean as a whistle.

Could this be an issue with the pump? Putting too much demand on the engine? Maybe it's bound up somehow? I don't know much about the pumps.

The engine starts and runs fine until I pull the water lever. The water starts and comes out well for about 3-5 seconds then it sounds like the load is too much for the engine.

A couple of new symptoms that have emerged during testing is that as I work the pump, it doesn't always engage and sometimes when I pull the handle and nothing happens, I'll let go of the handle. About 5 seconds later the pump will try to engage for a moment and then stop because I've released it. So that's acting a little squirrelly.

Not sure where to go from here.

[lefty]

New info.

The choke closes and flaps around under load. I missed that this morning. If I hold it open with a screwdriver, it runs smoothly. Choke only closes and flaps around under load. Otherwise, it stays open. Bad auto-choke? What would cause the choke to flap like that while under load?

I have the linkage set up properly. I took a picture before disassembly and have checked some other sources. It's got one of those auto-chokes that runs over to the exhaust. I think it's controlled by the heat of the exhaust?