Ran good when parked

DanR · Oct 25, 2012

Started the H yesterday after sitting for about four months. The engine surged badly even after it warmed up. I drained the gas (ethanol) and replaced it with real gas and some sea foam. Cleaned the fuel bowl. It ran a little better for a couple minutes then back to the surging. I'll clean the main jet today. Any other ideas?

MCOHIO · Oct 25, 2012

Could also be water in the fuel bowl or maybe just good old fashioned varnish from old fuel. I have heard that ethanol asorbs moisture as well as having a corrosive effect on metal parts not designed to work with ethanol.

David G · Oct 25, 2012

I would suspect an issue at the sediment bowl if it ran good for a couple of minutes then acted up again.

John G. Hasler · Oct 25, 2012

> I have heard that ethanol asorbs moisture...

Yes. That"s why gasline deicer contains alcohol. You"re less likely to have problems with water in your fuel if you use gasoline with ethanol added.

> ...as well as having a corrosive effect on metal
> parts not designed to work with ethanol.

No. Ethanol does not corrode metal.

ken house · Oct 25, 2012

open gas line at carb. you should have a good solid flow about the size of a pencil.

old · Oct 25, 2012

Surging is caused by it running lean so try these things. #1 pull the carb drain plug and let it flow for a couple minutes catch the gas so as to look for water/dirt/rust. If you do not have a good flow there work your way back till you find where clogged and fix that. If you have a good flow at the drain then #2 pull the main jet and needle out of the carb and again let gas flow there. If little or no flow use a small wire to poke into the jet it self to clean it out and then try to run it

The Red · Oct 25, 2012

To add to Ken's response, while you have the gas line disconnected, unscrew the inlet strainer assembly and see if it is clogged. I had that happen on one of my Hs.

MCOHIO · Oct 25, 2012

Check into the corrosiveness of ethanol. It is not transported by pipeline for that reason.

Dan Bear Kelley · Oct 25, 2012

I don't think it is the Ethanol, itself, that is corrosive. I think it is the water that mixes with the Ethanol that is corrosive. Ethanol can, however, eat seals, if they are of an unfortunate type.

Morris Krodle · Oct 25, 2012

Ethanol is not transported thru pipelines because it does pick up all the water in the line and that would be enough to ruin the ethanol. I worked at a fuel terminal for years and we had to drain our fuel tanks after every receipt because of water.

Captndan · Oct 27, 2012

Problem(s) solved. I actually started at the wrong end. The fuel bowl was cleaned twice. There was no screen. The fuel line has a circular bend it I guess for vibration. The lowest point of the loop had collected crud. The inlet screen was clean. The packing around the main jet needle had deteriated so some it had worked down to the seat. All the rest of the carb was clean except for a gray coating of some sort. Conclusion; Ethanol had collected water in the tank causing a very fine rust to collect in the bowl and line. The packing was deteriated cause unknown. Carb was rebuilt two years ago. The grey stuff in the carb appeared to be aluminum oxide. Cause unknown. My personal opinion is that ethanol is the culprit.

Ran good when parked

DanR

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MCOHIO

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David G

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John G. Hasler

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ken house

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old

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The Red

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MCOHIO

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Dan Bear Kelley

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Morris Krodle

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Captndan

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