Pressure Testing

[dsell]

I normally always replace the manifold on blowers they will show fine cracks around the studs causing leaks at higher pressures. I would just change the manifold out, do not over tighten the screws. Husky has those issues on some of their saws as well. Stihl has other issues, but still can be a pain. Keep working at it you will get there. You can also you strips of rubber which should work good to seal when doing a pressure/ vac test.

Can I use pressure on this type of manifold or should it be vacuum? I just found this for the Husky 55 which has a very similar intake boot that isn't clamped.

 

[SAWTECH1]

Can I use pressure on this type of manifold or should it be vacuum? I just found this for the Husky 55 which has a very similar intake boot that isn't clamped.

View attachment 946923

Are you working on a leaf blower , or a chainsaw?

 

[dsell]

Are you working on a leaf blower , or a chainsaw?

It's a leaf blower, 125BVX. I cannot find a workshop manual online for it.

 

[SAWTECH1]

It's a leaf blower, 125BVX. I cannot find a workshop manual online for it.

what point are you in the repair? Having trouble with? If that test booth fits, then give it a try.

 

[dsell]

what point are you in the repair? Having trouble with?

I have parts on order. The coil is weak and the intake manifold (plate) was loose. I have the plate, boot, coil, fuel line assembly with grommet on order. I'll pressure it up when I get the new parts on. The original question is about the correct method to pressure test. 4lbs, leak 3lbs per 30 seconds okay or should I use vacuum?

 

[grizz55chev]

Go electric.

 

[SAWTECH1]

I have parts on order. The coil is weak and the intake manifold (plate) was loose. I have the plate, boot, coil, fuel line assembly with grommet on order. I'll pressure it up when I get the new parts on. The original question is about the correct method to pressure test. 4lbs, leak 3lbs per 30 seconds okay or should I use vacuum?

I would use pressure to insure the seal are not leaking, but using your vac also insures the seal lips will not fold in around the crank aswell. both test have specifc purposes. Make sure you set the air gap on your coil/flywheel. i always try to wait 5 min for the testing, pressurize, then walk away, then come back and check it, if it passes we move on to final assy, if not find the leak. i would follow the pressure amounts listed for that machine.

 

[cookies]

 

[lchas]

Nope. No one can be forced to do anything; this is America.

I call bs on that!!

 

[SteveSr]

Nitrile gloves are too thin / weak to use for sealing a leak test. The glove material will just expand over time and muck up any readings. Being so thin it won't seal well either.

Should be thicker rubber like a layer (or 2) of bicycle inner tube.

 

[Binthewoods]

I use this. Plus a leather punch set to punch holes. The same punches are used when making gaskets.

Rubber Sheets, Black, 6x6-Inch by 1/16 (Pack of 3)

 

[J D]

+1 on the thicker rubber... find an old bike tyre tube to hack up.
Those minimum requirements for the 55 are a little to minimal for my liking, especially if you have future reliability in mind. As stated above, holding both pressure & vacuum is important & it's not uncommon for an engine being tested to pass one but not the other

 

[dsell]

+1 on the thicker rubber... find an old bike tyre tube to hack up.
Those minimum requirements for the 55 are a little to minimal for my liking, especially if you have future reliability in mind. As stated above, holding both pressure & vacuum is important & it's not uncommon for an engine being tested to pass one but not the other

Rubber is what's under the polychrome. That's what I normally used but I ran out. I've tested a Husky 455 and several Husky 350s that are prone to leak in various places. I've rebuilt several Husky 50 series, but I cannot remember if I pressure tested them.

 

[dsell]

Drop shippers suck. Never received any notification of backorder.

 

[dsell]

So, the intake is backordered until 1-10-22. I put it back together with the old intake and the pressure test held at 7psi for 15 minutes. That's when I stopped the test. Put the new coil on and sparks a little better. New fuel lines again but the new purge bulb hasn't arrived. Everything back together and it wouldn't fire. I took the purge lines off and plugged them, still wouldn't even burp. Put a new carb on and it finally ran. I probably got some water in it when I did the test. Got it all adjusted and it's still more sensitive, temperamental than it should be. I ran 3 tanks through it picking up leaves. There are times when it's just done running. Then, it takes several pulls to get it going. You don't dare push the purge bulb or you just as well walk away. The new one should be here tonight. The only other thing I can think of is a tank vent, but I don't think this has one. I've loosened the fuel cap several times when it acts up and it's never helped. I don't see any check valve system in the cap. I guess it could be a warped carb adapter leaking, so it's probably worth putting on whenever Sears decides to send it. If I just used this to blow the sidewalk off after mowing it would probably be fine. Grinding leaves gives it a good work out, and me too! Orscheln has $50 off $200 on the 18th, tempted to go get an Echo.

 

[TRTermite]

float level ok on the carb?? and the fuel pump getting stiff? might explain restarting hard when warm.

 

[dsell]

float level ok on the carb?? and the fuel pump getting stiff? might explain restarting hard when warm.

It's a new Zama carb.

 

[dsell]

One thing bugging me about this engine, there is noticeable side clearance on the ring. I should have measured it while I had the muffler off, but it seems excessive. Compression came in at 130 with my OTC tester.

 

[dsell]

The purge bulb arrived and I think it's finally running correctly. I ran two tanks through it vacuuming leaves without any issues. Part of the warm restart issues is that it will not run the last 1/8 of the tank of fuel. I guess tank/filter design doesn't work. If it had a felt filter with flaps it would probably work, but I'm not a fan of felt filters. I'm certain the person before me used ethanol. I believe that took out every part in the fuel system.

 

[dsell]

Oh my. They must be manufacturing new molds and building a plant to put it in.