Vacuum testing saw - how long?

[Lnk]

So I put a new piston in a 2094, used an inner tube gasket between carb and intake boot, and also between muffler and jug. I use the mightyvac to 7-10 inches mercury, and it creeps down to about 5" in 40 seconds or so. Would that be considered good, or does it need to be solid at whatever vacuum pumped to. I tried it with compression release and plug. Just looking to see if I need to get this better. First rebuild for me.

Pressure test failing at carb to boot right next to bolt, not much tube there, going to try to plug boot without carb. I do want to test the boot too.

Thanks for any advice.

 

[Lnk]

So I put a new piston in a 2094, used an inner tube gasket between carb and intake boot, and also between muffler and jug. I use the mightyvac to 7-10 inches mercury, and it creeps down to about 5" in 40 seconds or so. Would that be considered good, or does it need to be solid at whatever vacuum pumped to. I tried it with compression release and plug. Just looking to see if I need to get this better. First rebuild for me.

Pressure test failing at carb to boot right next to bolt, not much tube there, going to try to plug boot without carb. I do want to test the boot too.

Thanks for any advice.

@Mastermind
Can you move to general?

 

[Wonkydonkey]

I used a rubber bung in the carb boot.. & fashioned up something to stop it popping out on the pressure test,

i try not to do the p & v test with the tank and handle on the engine. As finding a leak is harder.

Soapy water is your friend on the pressure, but I use a thin oil like WD40 on the vac and always do the vac first.

 

[Lnk]

I used a rubber bung in the carb boot.. & fashioned up something to stop it popping out on the pressure test,

i try not to do the p & v test with the tank and handle on the engine. As finding a leak is harder.

Soapy water is your friend on the pressure, but I use a thin oil like WD40 on the vac and always do the vac first.

Rubber bung sounds like what I need to do. The handle is off, but the tank is part of the crankcase, as is the oil reservoir. I will pull the flywheel and oil pump when I redo the test. Thank you.

 

[Ronie]

I use a piece of closed cell foam and hold it over the intake with my thumb. works real good and I think it's easier to get a seal than using an inner tube, also works good behind the muffler.

 

[Benwa]

Everyone has a different "amount of time" they use for testing. If I have any pressure/vac drop within a minute or two, it's usually substantial in my book. I start spraying leak check on potential leak areas. I've found that often innertube is too thin. Rubber 1/8" or thicker seems to work better. I also trace the gasket onto the rubber, cut it out, and punch the holes for the studs/bolts. Seals up much better than just sticking a piece in there. With "like" saw models, often one piece you cut out, will work with a variety of saws.

 

[Woodslasher]

The service book will usually tell you what's "within specs". According to the book my 461 should only lose x amount of pressure in y amount of time, while other saws need to not lose any pressure for ~ X amount of seconds.

 

[Lnk]

The service book will usually tell you what's "within specs". According to the book my 461 should only lose x amount of pressure in y amount of time, while other saws need to not lose any pressure for ~ X amount of seconds.

I don't have a manual for my saw. Since Jonsered is no longer, who would I contact to get one? Husky?

 

[Wonkydonkey]

Ask @ray benson for your manual.. he’s a good fellow member and for fills many requests

 

[ray benson]

Ask @ray benson for your manual.. he’s a good fellow member and for fills many requests

Sent Larry a small Clymer 2094/2095 service manual along with a factory 2095 service manual. Also sent a factory 2071 service manual as it had a pressure testing section. Haven't seen a factory 2094 service manual.

 

[Homemade]

According to my Stihl 090 manual. It states pressure should he’s tested to 7.25psi and remain constant for 20 seconds. And vacuum should be pulled to -0.5 bar and not raise to -0.4 within 20 seconds.

I know it’s not supposed to hold vac or pressure forever. But a number to reference what is acceptable is always nice.


Sent from my iPhone using Tapatalk

 

[Homemade]

And my service manual for my 362 says roughly the same thing.

And thanks ray for the manuals


Sent from my iPhone using Tapatalk