Actron CP7826 Compression Tester

Basically.... the attachment length is too short for tapered cylinder heads. My old Sears tester has a longer thread attachment. I purchased this one to replace my old one and the needle on my old one was accidentally injured in using it! However, I had to go back to the my older tester. Has anyone else had a problem with the length?

If you're not a pro but want to know if you have even enough compression among cylinders, this is your tool. Used it to check my outboard compression and the tool works as advertised.For incidental usage I would recommend this tester.

Good budget compressor, I have used this on small engines and chainsaw motors mostly. Ended up getting the adapter set because this only comes with the stock size for plugs. If you need it for more than just automotive you may want to get the set that includes all the adapters. For a value-priced tester it really does a great job

This tester comes in 2 pieces: hose, and gauge.. Before assembling, I checked the pressure integrity of the gauge's pressure relief valve by simply blowing into the base of the gauge. I could tell that the gauge was not holding pressure; the relief valve core was leaking. What good is a compression gauge that leaks? I headed over to my local auto parts store and bought a pack of 4 tire valve cores, and a valve core tool. Replaced the 2 valve cores in the compression tester: the pressure relief valve core, and the other valve core in the base of the hose fitting that screws into the spark plug hole. After removal of the old valve cores, I could tell that they had much weaker internal springs than the new valve cores I bought. Tried the "blow" test again, and this time, no leak.With the gauge now holding pressure properly, I proceeded to test the compression on my snowblower engine. The gauge seemed to work properly, and the relief valve held pressure until I released it.So, the gauge works fine after replacing the 2 valve cores, but it's annoying that the manufacturer couldn't spend 25 extra cents to use quality valve cores in the first place.

I'm not sure how accurate it is but it seems to be at least pretty close. Close enough for me, though I suspect it's nearly perfect

I used this to measure the engine pressure of a used Jeep which I bought. I had no problems with it and it shows the pressure was fine.

I wanted this for the occasional check on my bikes. It was quite cheap and worked well. No problems. For occasional use I would recommend it.

When I got mine it showed a too-low psi. The weather was a bit cold. I put the device in the windowsill to warm up and then tried it and it worked normal. I took it apart and saw that the part that moves the needle is a curved copper "lung" that of course would be more resistant to movement in the cold because cold makes metal more stiff.