What's wrong with the B&S engine on my pressure washer?

[kebo]

I was using my TroyBilt pressure washer back in the summer (July 4th weekend) and best as I can recall it was running fine, when I shut it off. Recently I tried to fire it up and the pull rope was REALLY hard to pull, couldn't even get the engine to spin up fast enough to crank it had so much compression. Couldn't tell right off if the pump was the problem, or if it was the motor so I pulled the plug on it, which was the easiest thing to do.

With the plug out, I can pull the starter rope very easy and spin the engine over fast. I also noticed that it spit some motor oil out of the plug hole too. I know, not good. Put the plug back in and all of a sudden, it became hard to pull again. Seems like it is getting hydrolock with the oil getting in the combustion chamber somehow? I will admit I'm not much of a mechanic so if this is something that will require going into the engine, it might be better to buy a new engine. The pump that is on it now was just recently replaced last year so I know it's in great shape and pumps just fine. But, what is the most likely problem here?

 

[CCWKen]

Sounds like it was stored laying on its side or the air filter is so dirty the engine is sucking air through the crankcase vent. B&S made thousands of engines and Troy Built used many different models. You don't mention which engine you have. If it's an overhead valve engine, perhaps one of the rocker arms came loose and a valve stays closed.

 

[kebo]

It has a B&S 8.75 hp engine with a vertical crankshaft. The pressure washer was stored in its normal position, upright, or the crank vertical. If it will help, I can get the model number on the engine. Thanks.

 

[Walt 2002]

Suspect leaking float needle allowed gas to leak into the cylinder and on into the crankcase, so much gas it has raised the oil level to where the contaminated oil leaked past the rings and with gas in the cylinder is causing hydro-locking. You need to get as much of that out of the cylinder as possible. Blow it out with compressed air if you can't spin the engine fast enough to expel it. Change the oil of course and add an inline fuel shut off and use it when the engine is not running.

Walt Conner

 

[Rocky J]

If it is a overhead valve engine you might start with adjusting the exhaust valve , when the gap gets to big the compression release can not work as well and cause your symptoms. Looking at the picture you see a round piece that holds the valve open slightly until it starts then it will spin around to a flat side and let the exhaust valve shut completely. centrifugal force opens and closes it automatically if the valve adjustment is correct.

 

[Walt 2002]

Well of course he means lets the Intake Valve close and that would have nothing to do with spitting oil out the plug hole.

Walt Conner

 

[Rocky J]

Well of course he means lets the Intake Valve close and that would have nothing to do with spitting oil out the plug hole.

Walt Conner

No, I meant the exhaust, it would blow compression out the carburetor if it was the intake . When he said it blew oil out the spark plug hole, that the cylinder had been cleared of liquid from spinning it over with the plug out. You are correct on suspecting the bowl needle not holding back the gas if the tank is higher then the carb. Never saw a Briggs that did not drain into the crankcase. I have seen many Briggs Intek that the valve adjusting studs pull out of the head and will not stay adjusted, you tighten them up some and with time the pull the stud some, Not the Briggs and Strattons from years ago.

 

[Walt 2002]

"I can get the model number on the engine."
That is always helpful and I would like to have it.

"No, I meant the exhaust, it would blow compression out the carburetor if it was the intake"
This is why I wanted the model number since most, but not all, B&S engines both L head and OHV DO relieve compression via the Intake Valve "Blow compression out the carburetor".

"When he said it blew oil out the spark plug hole, that the cylinder had been cleared of liquid from spinning it over with the plug out"
Often using a recoil does not spin the engine fast enough to expel all the fuel/oil in the cylinder thus I suggested using compressed air to ensure complete evacuation.

Walt Conner

 

[kebo]

"I can get the model number on the engine."
That is always helpful and I would like to have it.

"No, I meant the exhaust, it would blow compression out the carburetor if it was the intake"
This is why I wanted the model number since most, but not all, B&S engines both L head and OHV DO relieve compression via the Intake Valve "Blow compression out the carburetor".

"When he said it blew oil out the spark plug hole, that the cylinder had been cleared of liquid from spinning it over with the plug out"
Often using a recoil does not spin the engine fast enough to expel all the fuel/oil in the cylinder thus I suggested using compressed air to ensure complete evacuation.

Walt Conner

I looked at the PW this evening, I couldn't really find a nameplate on the engine, with the model number/ serial number. Where would it be at? I did notice there is a metal plate just above the muffler with some numbers stamped into it. It is a 190cc engine with OHV. There is a nameplate with the MN/SN for the PW itself.

I checked the oil level to see if I could tell if it had any gasoline in it, per the first response about the float valve not working correctly. It didn't *seem* to have any gas mixed in with the oil, but I did notice that the oil level was above where it should be at, per the etch marks on the dip stick. Hard to say how much it was above full, but it was definitely above it. Now that I'm thinking about it, I do recall adding some oil to the oil fill when I last used it. If it was overfilled with oil, could that cause the problem I have now?

When I get home tomorrow, I will drain the oil and refill with new oil to the proper level, and then try and clear out the oil in the chamber best as I can and see what happens then. Thanks for the replies.

 

[Walt 2002]

Well I thought I sent a reply to this last evening but don't see it anywhere. It said - Oil does not have to be very much over full for it to run up into the cylinder and possibly leak past the rings into the combustion chamber causing hydro-lock. Sitting on an uneven surface may add to this affect. While there may not be enough gasoline present in the oil for you to smell it, I still suspect the oil was contaminated.

I have an engine similar to your general description. The model number is not as obvious as it should be. It is on the back side of the cooling shroud and starts with 12----.

I can send you a Service Manual for your engine IF you like. Address below, put in proper format and remind me engine model number and what you want.

Walt Conner
wconner5 at frontier dot com