Orion Motor Tech Gasoline Compression Tester Kit, 8pc Petrol Engine Compression Tester Set with 0-300 psi Pressure Gauge 4 Adapters, Small Engine Compression Gauge Set for Motorcycle Car Truck

I bought this to use as a pressure pump to pressure test my boat's outdrive because I saw someone else suggested online. I just bought the cheapest most generic affordable tool. I connected it to my outdrive oil filler attachment and the only modification I had to do was I had to buy two tightening screw clamps. In the end it works perfectly and I'm very happy. The build quality is really good. It's easy to use. The readings are very accurate. I especially appreciate the relief valve to allow me to depressurize rapidly. Very happy with this tool and if I ever need for brakes it'll be useful for that too. The case it comes in is super nice. I have a few tools like this that come in similar cases and they all stack really well on my shelf.

Pretty decent test kit. Love the spark tester

EDIT: though I was well past the return date because I wasn’t at the point of my tune up to test my compression, as other reviewers said, the customer service was fantastic, and they sent me a replacement gauge. So, you can purchase knowing that if there’s an issue, you will be taken care of by this seller. Thank you! Original review: Pressure not accurate. Did test twice on separate days (because I was so disappointed in my results initially). Yes, my engine was warmed up, yes I had the throttle fully open, and yes the choke was open (not choked). My results were CONSISTENT, but not accurate. Gauge measured 90, 65, 85, 90. Then I did the tsp of oil test down the spark plug wells, and I got 95, 90, 90, 95. Yes, I know no. 2 is a little off, and it would be a concern at this level. I took my bike to my mechanic to weld a hoop on, as I don't have a welder, gave him my numbers and asked him to check for me. I went in today, and he said my compression was fine: 150, 125, 150, 150 and that while no. 2 is a little concerning, its within the range that I'll be O.K. at least for now. Of course, I'm past the return time, so I'm stuck with an inaccurate compression tester.

Bought a 1986 Honda atc 250r that hadn’t ran in over a decade so I was nervous that the compression could be low after it kept not idling. This compression tester kit was high quality and helped me by reassuring me that the compression was within spec.

Performed as expected. Results less than desireable, but that's not the tool's fault. I'll attribute the poor compression to a long string of POs on a 45 year old bike.

This product has the right idea, ill give it that. But I used this on a stihl bg55 blower i was having issues with, decided to check the compression with this tool, it showed less than 20psi. I figured the piston rings were bad so I tore the motor apart. Come to find out the tester just sucks. I used it on another engine im working on, which has good compression just by feel, but I wanted to test the tool to see if it was a fluke. That second tool with the spark plug in, has good compression, hook up the tester, and the piston seems to spin a lot more freely and once again only shows about 20psi. So something is leaking on the tester somewhere, and I saw some other buyers claimed the same thing. Don't waste your money on this tester. Im going to purchase the mityvac compression tester here soon as it's build quality seems a lot better. Saw a comparison video between the two and the mityvac has Schrader valve in the line, to keep the pressure in the gauge helping to give a more accurate reading.

Buen kit

I purchased this product specifically for small 2 stroke and 4 stroke engines (I work on small engines as a hobby.) I have another cheap Amazon compression tester kit, but the results are always way too low, especially with 2 strokes. I read online these kits with a Schrader valve work much better for tiny 2 stroke engines because they hold pressure properly to get an accurate reading. That is the primary purpose for buying this kit. I have two weed trimmers one is an Echo and the other is a Husqvarna. This tester kit ready 50psi for both engines, which is literally impossible (these tiny two strokes need 120-160psi to run strong.) I'm sure this kit works good for a car engine but it's not accurate for small engines... I'll be returning it.