Honda GC160 engine drowning...

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Pete C. - 08 Nov 2007 16:20 GMT

I've got a pressure washer that was given to me that has a Honda GC160
(cheap line) engine that seems to be drowning in gas. If I disconnect
the crankcase pressure pulse hose to the fuel pump after the carb bowl
is filled it will run seemingly ok until the fuel in the bowl is
exhausted. If I leave the fuel pump drive line connected it will flood
to the point of hydro-lock if you keep trying to start it.

I pulled the carb and ran it through the ultrasonic cleaner on the
theory that perhaps some junk or varnish was preventing the float valve
from seating, but it didn't solve the problem. I'm rather suspicious of
the float as it is a single piece molded plastic piece with no
adjustability. If I manually lift the float the valve does seem to
close, but I can't tell if it would be at the correct level.

Anyone have experience with these engines and know what might be the
problem? Anyone know a better group to post this to?

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jim - 09 Nov 2007 00:43 GMT

> I've got a pressure washer that was given to me that has a Honda GC160
> (cheap line) engine that seems to be drowning in gas. If I disconnect
[quoted text clipped - 9 lines]
> adjustability. If I manually lift the float the valve does seem to
> close, but I can't tell if it would be at the correct level.

The correct level is usually designed to be level. That is the top of the
float would be level. if it is not adjustable it probably would be
noticeable if it were cracked or deformed in some way.
When you say the valve closes does that mean it shuts off the flow of
gas? If you turn the empty carb upside down it should shut off and the
line so that it will hold a vacuum. Then turn it right side up, you should
be able to blow air thru it easily.

> Anyone have experience with these engines and know what might be the
> problem? Anyone know a better group to post this to?

The float is what keeps the gas from doing exactly what you are
describing. Does the float float? If it were floating and not sinking it
should shut off the gas flow and your problem would go away. Obviously
it's not doing that. Either the needle is not seating and thus not sealing
or the float is damaged and binding or if it's full of gas and it's not
floating.

-jim

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Pete C. - 09 Nov 2007 02:35 GMT

> > I've got a pressure washer that was given to me that has a Honda GC160
> > (cheap line) engine that seems to be drowning in gas. If I disconnect
[quoted text clipped - 13 lines]
> float would be level. if it is not adjustable it probably would be
> noticeable if it were cracked or deformed in some way.

The way it's all one plastic piece, including the tab that actuates the
aluminum valve pin, makes it difficult to tell if it's deformed not
having a new one for reference.

> When you say the valve closes does that mean it shuts off the flow of
> gas? If you turn the empty carb upside down it should shut off and the
> line so that it will hold a vacuum. Then turn it right side up, you should
> be able to blow air thru it easily.

The fact that it has a fuel pump, not gravity feed, combined with tight
quarters around that carb make it difficult to test it in place. All
I've tested is that when I had the carb out I was able to blow in the
fuel port and stop the flow by lifting the float.

> > Anyone have experience with these engines and know what might be the
> > problem? Anyone know a better group to post this to?
>
> The float is what keeps the gas from doing exactly what you are
> describing.

For a typical gravity feed setup, yes, with the fuel pump setup I'm not
sure. Possibly a fuel pump issue could send more pressure than the float
can shutoff? Certainly the carb will flood very quickly if the fuel pump
is enabled.

> Does the float float?

Good question. Being plastic I'd not thought that would be an issue vs.
the brass ones I've seen with holes, but I'll have to pull it apart
again and check that.

> If it were floating and not sinking it
> should shut off the gas flow and your problem would go away. Obviously
> it's not doing that. Either the needle is not seating and thus not sealing
> or the float is damaged and binding or if it's full of gas and it's not
> floating.

That would make sense. Just never dealt with a fuel pump setup or a
plastic non-adjustable float before.

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jim - 09 Nov 2007 03:22 GMT

> > > I've got a pressure washer that was given to me that has a Honda GC160
> > > (cheap line) engine that seems to be drowning in gas. If I disconnect
[quoted text clipped - 38 lines]
> can shutoff? Certainly the carb will flood very quickly if the fuel pump
> is enabled.

Being a pump or gravity feed shouldn't matter. the needle valve should be
able to handle a lot more pressure than the pump can make. Anyway, there
really isn't any way that an old pump by itself would produce more
pressure than when it was new.

> > Does the float float?
>
> Good question. Being plastic I'd not thought that would be an issue vs.
> the brass ones I've seen with holes, but I'll have to pull it apart
> again and check that.

If it is hollow then it must have a seam and that could leak. I wouldn't
expect a hole but maybe a crack. They didn't use plastic because it was
better and more reliable - they used it cause it's cheaper.

-jim

> > If it were floating and not sinking it
> > should shut off the gas flow and your problem would go away. Obviously
[quoted text clipped - 4 lines]
> That would make sense. Just never dealt with a fuel pump setup or a
> plastic non-adjustable float before.

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