[commrad]

Just did about an hour of bush hogging in the pasture and didn't notice any problems until I dropped the engine to idle, it didn't have that clanky diesel idle, all most smooth. I thought it was just me. Throttled back up and it was extremely slow to come back up to cutting speed so I let it idle about 3 minutes and it was fine.

At first it scared me, I thought the compression was gone but after it idled a few minutes it was fine again. I've never ran it that long with a full tank before. Is it possible it vapor locked or more like vacume locked? since there was very little air in the tank. There is no visible vent in the tank is the reason I ask.

It wasn't over heating at all and the filter is good.

 

[BruceR]

Shouldn't your cap have a vent? Maybe pop the cap next time and see if it helps.

Bruce

 

[winston]

Not for sure, but I think the plastic strainer under the cap some way acts as a vent. I read if it is removed you loose you venting. Not sure all models are that way.

 

[commrad]

Shouldn't your cap have a vent? Maybe pop the cap next time and see if it helps.

Bruce

no, it has a yanmar cap with is a solid piece of plastic with no vent hole anywhere that I can find.

just ran it about another hour, didn't do it quite as bad but it did start to, cracked the cap a little and it picked right up.

Think I'll get a T fitting and put a filtered vent on the line between the thermostart bowl and the tank. If I ever get time to do it I'll take a pic and post it.

Not for sure, but I think the plastic strainer under the cap some way acts as a vent. I read if it is removed you loose you venting. Not sure all models are that way.

I thought it would, maybe mines been replaced with something for a different animal. I checked it for any sign of a vent hole ect and there is nothing. The under side of the cap has the rubber anti slosh baffle but there is no vent in the cap. wonder if they just forgot to drill or punch a vent in the thing.

 

[mark777]

Command,

You model should have the neck strainer, just as Winston said. The space between the strainer and cap threads is your vent.

I have replaced a fuel tank (on a YM1401) that collapsed from internal vacuum, heat and due to the lack of a vent.

Mark

 

[commrad]

Figured it out, some one had put an oring in the cap and it had gotten so flattened out that it looked like part of the seal/baffle that was suppose to be there. Pealed the oring off and whata ya know the seal has two vent holes in it.

 

[JackM]

I had a neighbor that had a collapsed fuel tank from venting but it was on a non-oem fuel tank, some thing he rigged up himself.