Compression tester

[cpr]

It has the Schrader at the bottom, but I don't remember what adapters came with it. It's been in a drawer under the Actron one and I haven't pulled out in probably 4 years. I'll have to drag it out when I get home tonight.

 

[lone wolf]

I was going to buy the 10mm hose for my Snap-On gauge, but they want $49.95 for it.

So buy it ! it will last for life!

 

[Cope1024]

So buy it ! it will last for life!

I know, I bought my Snap-on set used in the early 1980s. IIRC, I paid less than $50 for the whole set. Problem is that I don't have anything with the 10mm plug.

 

[cpr]

Here's the Lisle one. First time I've touched it in forever. Needs new o-rings on it.

 

[pioneerguy600]

Here's the Lisle one. First time I've touched it in forever. Needs new o-rings on it.
View attachment 731186

Does the small adapter have a valve in it?

 

[cpr]

The adapter doesn't, but you can just see the pin of it on the main hose that does the other 2 sizes.

 

[pioneerguy600]

The adapter doesn't, but you can just see the pin of it on the main hose that does the other 2 sizes.

Yes, that is where the problem lies with this adapter stuff, the adapter needs the valve in it to get a correct reading, if the adapter does not have the valve in it then a lower reading will be the result.

 

[cpr]

Right, though I have never used that adapter on a saw. None of them have a plug that recessed.

 

[pioneerguy600]

I don`t own a saw that has a 10 mm plug yet but the odd one has come and gone through here but they were rather new and had no piston or cylinder damage and not enough run time on them for ring wear. Won`t be long before some start dribbling in that may need a compression check so must have a comp tester or adapter on hand that will give a reliable reading for diagnostic work.

 

[brad ruch]

We'll decided I needed a good one with shrader valves in the end[emoji6]

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[stihl86]

We'll decided I needed a good one with shrader valves in the end[emoji6]

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Nice tool. Now just figure out how hard/fast to pull the recoil rope, for each displacement saw and you’ll be all set.
And make sure you do it repeatedly. You need consistency.
Because, the main reason to use a compression gauge is for comparison between cylinders.
That’s why many small engine manufacturers recommend NOT using one. Unless of course, you have
6 cylinder saw?
Why do they offer so many hoses to fit a small engine? Because you want to buy it.

 

[brad ruch]

Nice tool. Now just figure out how hard/fast to pull the recoil rope, for each displacement saw and you’ll be all set.
And make sure you do it repeatedly. You need consistency.
Because, the main reason to use a compression gauge is for comparison between cylinders.
That’s why many small engine manufacturers recommend NOT using one. Unless of course, you have
6 cylinder saw?
Why do they offer so many hoses to fit a small engine? Because you want to buy it.

Ok I'll remember that[emoji6][emoji6]

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[TheTone]

The best compression tester for chainsaws is one you can build from a 14mm or 10mm sparkplug. I have a post in the archives about how to do it. It might be listed under Okie's name, I don't remember. The two important things are: (1) the schrader valve must be the special low opening pressure type (opening pressure in ounces, not pounds) and (2) Schrader valve at screw in to cylinder, NOT at end of tube at gauge (the reason is in archived post; hint: PV=nRT). Get these two right and you'll get an accurate, reliable, and USEFUL reading.