INNOVANT 9 Piece Set Complete Deluxe Gasoline Fuel Engine Automotive Compression Test Kit w/ Inline Spark Plug Tester- Detects Leakage Up To 300 Psi (21 Bar) Quickly Diagnose Internal Leaking Problems

I plan to use this on small engines but was disappointed to find that only the M18 adapter has a hex head.  The rest can only be finger tightened so I question how accurate the readings will be.  Plus the O-rings or washers on those adapters are soft and easily destroyed.  As others reported, I had to use Teflon tape to seal the gauge to hose connection.And, also as others reported, the "free" spark plug tester does not work.  Bulb looks to be cracked.I've reported this to the seller and am awaiting a response. Will update with results from my interaction.UPDATE- Seller responded to my issue with a new instruction manual which specifically states not to tighten beyond hand tight. Too little, too late for me as the o-rings are already damaged. They did replace the spark plug tester with one that works. Upgrades rating from 2 to 3 as they have known quality control issues which they have not addressed.

The media could not be loaded.  I purchased this for doing a simple compression test on my dirt bike. Out of the box, it would drop 10 to 15 psi slowly over a few seconds. After contacting the seller, they asked me to spray a water and soap mixture (1 part dish soap, 20 parts water) on all the fittings as the tester was full of air to find the leak.Worked better than I thought. It was leaking at the gauge area and the pressure release valve (soap and water mixture clearly bubbled up at the areas). The seller told me that some parts may have come loose in shipping and offered to send me some thread tape, but I already had some, so I told them not to worry about it.I took the gauge off and put the thread tape on it, put it back on (really tight at the end) and that took care of the leak at the gauge. The pressure release valve has an O-ring on it, so I just tightened it slightly more with my fingers and that leak went away, no need for thread tape.Now, it has no leaks and holds 150 psi without dropping down any. I gave this 5 stars cause the seller was so good to work with and at the end the product works perfect. Will buy from them again!

I wish this thing worked properly. The seller is amazing, very helpful and responsive. When I discussed my problem with them, they immediately sent me another unit. Unfortunately that one doesn't work either (see below), and they immediately sent me a refund. So, bad product, great customer service.The problem with this tester is the flexible hose to connect it to the spark plug hole. There are various fittings to help check your compression - 2 fixed pipes with rubber cone tips, to push into the plug hole, and one flexible hose with various adapters to screw into the spark plug hole. The rubber-tipped cones are very inaccurate and almost impossible to use, as you can't hold them in the plug hole while cranking the motor. Even if you have an assistant to crank the motor, the plug hole is difficult to access and you won't get an accurate reading. So the screw-in fitting is necessary. Unfortunately there's no Schrader valve in that fitting, meaning the gauge won't hold pressure. As you're cranking the motor it will bounce up to the maximum pressure, then immediately fall down to 30psi or less. The problem is a design flaw. The engine cylinders will not hold the highest pressure themselves - once you stop cranking the motor they will almost certainly stop with a valve (intake or exhaust) open, so the air will leave the cylinder. Since there's no Schrader valve on the gauge, it will leak and the gauge will go down. I tested this on both units they sent me, with my air compressor.It's really a bummer, because otherwise this seems like a great deal and a very helpful company, but the tool simply doesn't function this way. They need to add a valve to the flexible hose for it to be useful. Save yourself the time I spent on this thing, don't get it.

Very impressed with the completeness & overall quality of this set. For the price, I don't see how you can beat it.Paid for itself in just one use by demonstrating that the doom-and-gloom diagnosis of a "professional" mechanic was bunk.I was able to use the threaded adapter and hose rather than the rubber cone on my easy to access motorhome engine, but I suspect the threaded units might be difficult to use on some more modern vehicles, where just changing spark plugs is a chore almost equal to an engine swap. In any case, the kit has enough options to do the job regardless.

The tester did not have a long shank attachment for a FOR 4.0L

work the way it should. good for a lower dollar set

I purchased this almost three years ago and it never has worked. Testing the compression on my Ford 289 small block the needle bounces between 60 and 150 psi. I emailed the seller when I bought it and they told me to spray soapy water on it to see if it was leaking at any of the fittings. They even offered to send me some Teflon tape. I already had some tape so I re-taped the connection to the gauge and sprayed it to check for leaks. There was no bubbling at all but it wouldn’t hold more than 60 psi on the gauge when using the connection hose.Today, almost three years later I thought I’d give one more shot at repairing the gauge before resorting to buying another one. This time I noticed the check valve in the connection hose looked crooked. I hooked my compressor up to just the hose and the check valve doesn’t seal, letting air escape. So, all of the screw-in adapters are useless since the hose won’t hold any pressure.I see this item is no longer available from this vendor. They probably just print a different label on the package and move on to the next mark.

I used this tester to help me check a 1953 Chevy Belair. It was easy to use and worked great!