the saga continues... PT-425 engine problem at 10 hours?

[dcdtn]

Well now, big help I am.
Seen that carb before but not familiar with it at all.
Maybe Subura decided its a better carb than that overly sensitive thin I'm talking about.
Looks like a guy could drop that float bowl and have a look.

You gave me the idea and confidence to check carb. So let me give you a big thank you!

Now for the update... I think I've got it running now (fingers crossed). I carefully disassembled carb. Blew out every hole I saw. Reassembled and and tried running it. It ran better but would cut out every 5 minutes or so. It did this 5 or 6 times before running a good solid 20 minutes without issues before I quit for the day. So I hope it's fixed and the cutting out every 5 minutes was just the air working itself out of the system. I'll run it some more tomorrow to be sure.

Not sure if the motor oil type residue in the float bowl is cause for concern? (See pic). There's definitely been at least a little oil making its way into the air intake through the rubber hose that goes to the right cylinder head.

 

[KentT]

That hose from the valve cover provides crankcase ventilation. As the engine gets fully broken in, with the piston rings seated well, that crankcase pressure (and the oil it carries with it) should go down dramatically. I'd keep an eye on it, but wouldn't fret about it....

 

[MuncyBob]

I would run some Sea Foam thru it soon since it's now running, helped me. On he muffler, yes the stock one is outside the cage/lid. Problem with the PT exhaust is the 90 degree bends. The Subaru exhaust ain't cheap and you even have to cut it but it works.

 

[SimS]

That "motor oil type residue" looks an awful like the gunk in your fuel filter. PCV vapours are directed into the air intake and not the fuel system. I think you have some sort of contamination in your fuel. Given your fuel filter and float bowl photos. I would flush out your fuel system with known clean gas container and fuel source. The Sea Foam wouldn't hurt either, it would help in the clean up. Good luck.

SimS

 

[elderlyphart]

I'm pretty sure there is a drain screw on the bottom of that bowl. After running it for awhile drain the float bowl into a clean white cup and see if any crud is still wondering around in there.
Fouled gas from sitting to long at the factory?
Anyhow sounds like you are on top of the problem!
Good work. Now l know who to ask if I tangle with one of those suburu sidedraft carbs.

 

[dcdtn]

I'm also wondering if I got a bad batch of gas. I purchased about 12 gallons on one of the days everyone was making a run on the gas stations around here because of the pipe line rupture. Maybe I got the left over crud in the bottom of the gas station's tank?

 

[dcdtn]

Ok. I'm about ready to throw in the towel!

It's still cutting out every 5 minutes or so just like it did yesterday after blowing out the carb. Before I began today I siphoned out all the old gas and replaced with fresh gas from a different station and treated with Sea Foam. I also applied the spray Sea Foam to the carb.

It's acting like it's running out of gas. The fuel line has all kinds of air (it's the clear see thru type). Fuel filter bulb barely has fuel in it.

I've fished a couple of nickel sized clear silicon (or plastic) membrane pieces out of the tank, so I suppose it's possible there's still something clogging it? I'm running out of ideas at this point. Think I will call Terry and see if I can arrange to bring it in. It'll be a good excuse to take a vacation in the VA mtns.

 

[elderlyphart]

Plugged gas cap vent? Seen it happen.

 

[Marks481]

I've fished a couple of nickel sized clear silicon (or plastic) membrane pieces out of the tank, so I suppose it's possible there's still something clogging it?

That is the stuff that people have seen clogging the elbow at the bottom of the fuel tank.

 

[ponytug]

The bubbles are suggestive that you still have a blood ckage or restriction in the fuel line. If you see bubbles in the tank, I would think about the plugged cap as well. I've had it happen on a weed hacker.

All the best,

Peter