I ran my pressure washer the other day to wash my car and truck. I didnt have any regular gas handy so I filled it with E85. Everything ran fine till I got near the end of the tank then I started losing water pressure. I checked the oil and it seemed fine so I went and got some regular gas and still the water pressure isnt where it should be. While it was running the oil dipstick came loose (because I didnt have it on all the way) and it seemed like there was a lot of crankcase pressure. I started thinkin I might have destroyed my rings. Is that possible? I havent ran a compression check yet. I might try that tonight. Has anyone else heard of such a thing?

 

You mean oil pressure?!?

 

No I meant water pressure. Its a typical pressure washer. Its like the motor doesnt have enough power to work the pump hard enough to get up to pressure. Ive still got to look into it. Maybe the pump is crapped out or something. I was just wondering if anyones heard of rings going bad from E85.

 

The engine was running lean on the E85, so if for some reason that caused some detonation, something could have broken. I wouldn't think that the compression ratios of those small engines would be enough to cause any detonation issues, but I suppose stranger things have happened. Can you easily pull the cylinder head (i.e. flat head engine) to see if anything is amiss inside the cylinder? I've never had any mechanical engine problems while running E85.

 

I will dig into it tonight and let ya know.

 

It appears theres no compression. When I pull the cord the compression gauge goes up to 60 but immediately drops to 0. Through the spark plug hole I can see the piston has shinny speckles on it like metal bits.

 

What kind of engine is it?

 

Its a 7hp ohv Briggs & Stratton. I looked on the Sears website for parts and the motor is discontinued. They must use some el cheapo rings or something. The pressure washer is only 2 years old. I went to Briggs website for a rebuild kit but it wasnt workin right for me. Maybe I will have better luck tonight.

 

What did the spark plug look like? Ngk has a good plug gauge chart on their website
compare it to that and you can tell alot on how the motor is running. The thing
about that first tank of e-85 is that any crap or water in the tank is getting dragged
out all at once!! You should completely drain the tank and carb(of course hindsight)
and then fill up the tank and this goes for anything not just small motors and wether
it is Methanol or E-85 that you are switching over to. Put a half a teaspoon of some
two stroke oil in the plug hole and try your compression test and see if it goes up.
If You can't find the rebuild parts go ahead and run 2 stroke oil in the gas and you
can get a few more hours out of the motor, Pulling the head and cleaning the valves
and the top of the piston/ combustion chamber and plug when it starts running rough
from the oil build up is all that is needed. Probably start at 75:1 ratio and see if it can
get enough compression to run if not then 50:1 but not much more than that. If it
still has trouble starting on the 50:1 then pull the plug and put a bit in there and it
should start up and then run. I did that with a buddies club car he didn't have any
money to keep it running and the company said they weren't going to pay to rebuild
it, It had like 35psi in the low cylinder and I ran it at 50:1 and a year later that thing
is still going strong without even ever pulling the head. Since he loads it down with
all the tools and crap and the property is pretty big it gets hot enough and only needs
the plug cleaned up every 8-10 hours of running!!

 

Most small pul lstart engines have a compression release built in to the valves. You won't see any good compression until the RPM's build up the the release kicks off. IIRC, it's a little lever built into the exhaust valve/cam, so there is no way to bypass it w/o tearing apart the engine.

Never heard of E85 hurting rings - lots of engines use it with only minor changes in the fuel system. Like has been said before, it might have dissolved some crap in the fuel system and/or fuel filter and caused a blockage.

 

I havent messed with it much yet but that pressure bypass might be something worth looking at. The pressure washer isnt very old maybe 2 years and I dont exactly use it a whole lot. The last time I ran it was before winter. I ran it completely out of gas before I stored it inside out of the cold. The spark plug looks fine to me altho a little wet with oil but that could be from tilting the unit while it was running thinking I needed to work a bubble out of the pump. The head looks easy to get to. I will post how it looks in there when I get around to it.

 

Got to put in my 2 cents worth, since I work on these things for Sears. I seriously doubt you have hurt the engine itself. As mentioned earlier, these engines have a compression release, and wont build compression until the engines have hit a certain RPM. This engine will have a float bowl type carb. The E85 has swolen the needle valve seat. It is some kind of rubber, and will shut off the fuel flow to the carb when alcohol gas hits it. You will also note when you pull the float bowl, the o-ring will have swelled way out, and cannot be reused. You can knock the needle valve seat out with compressed air (ask me how I know), and replace. A new carb will also cure. Sears always shows the engine as unavail, however, take the numbers off the engine and run it through the Sears website, and you will find the parts breakown. Rural King can also get parts. Leave the head alone - it's a Briggs, it will survive. DONT use alcohol fuel in the future - you kill the carb again! Try to avoid even the 10% stuff - but is getting harder. They oft put more in than what the pump says - so get the regular.