Husqvarna 394 Intermittent Lean

[Winn R]

Husqvarna 394 Intermittent lean



Although I didn’t see the crack in the intake, I converted it to a 395. Intermittent lean continued. Changed fuel line, seals, checked carburetor, same problem. Installed new impulse connector to cylinder. New impulse line. Broke down case. New bearings, checked case fit, looked for pinhole, checked crank, extra care fitting gasket - same intermittent lean. Stopped playing with the carburetor, got a new one.

Good thing I’m bald already.

I must’ve missed something. I can’t think of anything new to try.

 

[grizz55chev]

Husqvarna 394 Intermittent lean



Although I didn’t see the crack in the intake, I converted it to a 395. Intermittent lean continued. Changed fuel line, seals, checked carburetor, same problem. Installed new impulse connector to cylinder. New impulse line. Broke down case. New bearings, checked case fit, looked for pinhole, checked crank, extra care fitting gasket - same intermittent lean. Stopped playing with the carburetor, got a new one.

Good thing I’m bald already.

I must’ve missed something. I can’t think of anything new to try.

Vac- pressure check

 

[Winn R]

Vac- pressure check

Thank you sir. I can only get the lean while playing with it hard. Typically milling. By the time I get it out of the frame and set up, I get no leaks.

 

[Squareground3691]

Check with brake cleaner around seals ,base of cylinder, intake if it stalls out u have a leak issues

 

[grizz55chev]

Thank you sir. I can only get the lean while playing with it hard. Typically milling. By the time I get it out of the frame and set up, I get no leaks.

I've had some saws in the past that gave me fits, my last resort was to strip it down to the case with the jug installed, plug the intake and ex., pressurize it with 7 psi and dunk it in water like looking for a flat tire. Also, check the comp release, they sometimes have intermittent leaks!

 

[Winn R]

Thanks for the responses.
The system here generated similar threads and one said check the tank vent. Ok - I’ll try again!

 

[John Stryker]

I had a 395 that leaked between the oil tank and the crankcase through the gasket. I split the case and found the mating surfaces of the case were not flat. I flattened them with sandpaper, and then with a new gasket, bearings and seals all was back to normal. It was an intermittent problem also, depending on the oil level.
Another possibility could be the carb air locking from excessive heat.

 

[Winn R]

Thanks for the responses.
The system here generated similar threads and one said check the tank vent. Ok - I’ll try again!

And I’ll ckeck that comp release!! I did reuse the old one.

I had a 395 that leaked between the oil tank and the crankcase through the gasket. I split the case and found the mating surfaces of the case were not flat. I flattened them with sandpaper, and then with a new gasket, bearings and seals all was back to normal. It was an intermittent problem also, depending on the oil level.
Another possibility could be the carb air locking from excessive heat.

yes. I thought it would be the case half fit earlier and checked it with a straight edge. How would I check a carb air lock from heat?

 

[John Stryker]

I'm not sure how you would check for carb air lock other than maybe trying without the top cover. The 395 intake boot should be a better insulation from heat, so maybe that isn't it anyways.

 

[eriklane]

I converted a 394 also, and it has seemed to me to be up and down in performance, but I'm too old to remember what exactly transpired since the conversion. Now it pulls now fuel. I've checked the fuel line, newer filter, and cleaned the carb 2x. I've just pulled the welch and it's clean, and will reclean there and retry. In the meantime, I bought a new carb as this one has grooves on both ends from years of use, so who knows? If this don't work, then I'll retry the pressure test on the jug...Pretty sure I had done that and it was good. Impulse line is newer and also intake same.

 

[John Stryker]

I converted a 394 also, and it has seemed to me to be up and down in performance, but I'm too old to remember what exactly transpired since the conversion. Now it pulls now fuel. I've checked the fuel line, newer filter, and cleaned the carb 2x. I've just pulled the welch and it's clean, and will reclean there and retry. In the meantime, I bought a new carb as this one has grooves on both ends from years of use, so who knows? If this don't work, then I'll retry the pressure test on the jug...Pretty sure I had done that and it was good. Impulse line is newer and also intake same.

Yes, pressure / vac test might tell you something.