compression tester

[Bryansg3]

is there a specific brand tester anyone would reccomend. I have a 394xp and I think it's time for new rings. My stock 460 cuts with it. both on full skip chisel chains. Don't understand why the 394 is not cutting circles around it. I was in some really hard wood today, but one would still think the bigger saw should be faster. any advice would be helpful

 

[galde]

Sears has one, also any auto parts store should have one. Make sure the Shrader valve (it is like a tire valve, except that the core has a very weak spring) is located in the threaded end that screws into the spark plug hol;e. There should also be a pressure release button on the gauge end.

 

[stihl86]

Rings are probably fine. Stihl's are just superior to huskys, regardless of size.

 

[Bryansg3]

thanks

thanks for the help. could anyone tell me what is the lowest you should run the compression before changing the rings out. Don't know much about the numbers, however I don't want to have to replace the cylinder if I don't have to.

 

[GA_Boy]

After having tried 3 different compression gauges, i can tell you they are not all the same. The one from the auto parts store was garbage and wouldn't give over 120 psi.
The last one i bought was this one and the build quality is excellent.
Longacre Racing Products 73025 - Longacre Compression Testers - Overview - SummitRacing.com

 

[atvguns]

did it come with spark plug adapter

 

[dh1984]

well you know you could always make you one like i did onced.but i let a friend of mine use it and never seen it since but i'm planing on make a other one though

 

[nmurph]

lots of us use the Actron. i bought mine from AutoZone but they can bought from other autoparts stores. i only know of one person on AS that has had a problem with ttheir's. i have tested mine against both a Snap-On and Mac, and it was within a pound or so of both. the main thing is that you test the saws when they are cold and pull until the tester stops gaining.
as for speed, the 460 may well be a little quicker. it really depends on the size of the wood. the 394 will start to shine with longer bars.
i would start to think about re-ringing when compression gets below 135psi, though your saw will run fine with less compression.

 

[67L36Driver]

I have a comp. tester from Sears. Used it a lot in the past eight weeks.

My rules of thumb:

Below 120 = Forget it, it won't pull for squat.
120-130 = Long shot, don't get your hopes up.
130-140 = Got a runner. A little weak.
140-150 = Good runner. We smilin'
150+ = Weeeeeeeeeeeeeeeeeeeeee!

I've gone thru these 14 power heads in the past month and the above holds true.
View attachment 169552

I have retested some of the runners and most have stayed the same but some have improved.

 

[GA_Boy]

did it come with spark plug adapter

Doesn't need it, it's standard 14mm thread.

 

[67L36Driver]

Doesn't need it, it's standard 14mm thread.

With the Sears Craftsman you get an adaptor for the long reach 14mm that screws on the end of the short 14mm that is on the end of the hose. Somewhere I also have the 7/8" adaptor for the old Fords. Used that on my son's '66 pickup.

 

[ttyR2]

Compression tester set from Sears:

 

[indiansprings]

Mine is a Lisle, bought it at a farm supply store, compared it to a Snap On at the local auto shop and it's within a pound, I have used it three or four years and it's worked great. Remember you have to crank it several times to fill the hose up to get an accurate read, usually for or five pulls. I think mine was about 30-35 bucks.