Lisle 20530 10mm Spark Plug Adapter

The rent-a-tool automotive compression testers from auto parts stores do not normally have a 10 mm adapter. This worked great multiple times to adapt them for my KTM motorcycle. It did perfect. I never had a bad thought about this item even while I might have struggled through other problems. Cool...did it's job.

I needed to check compression on a small engine I am working on and my old tester came with no adapters. I pretty much guessed at the size but figured it would be correct, it was. This adapter comes with 2 rubber O-rings, one for the engine side and one for the tester side. No need to reef it down just snug it up a little and it seals fine for 160 PSI. Good quality brass fitting should last forever.

fits in most glow plug holes to test diesel engine compression

Wasn't quite deep enough for my Honda crf250r, but I couldn't find the right tool anywhere. There was enough meat for me to machine the neck a few mm longer and then it was perfect for my application. You can't machine more then a few mm's though

The 10mm adapter that came with my compression tester leaked at the cylinder head. Found the Lisle 10mm adapter and gave it a try. Its slightly longer into the cylinder head than the adapter than came in my OTC Kit. Happy to repair this sealed perfectly and I was able to get good readings.

I test the compression of my outdoor power equipment annually. The 10mm spark plug adapter can also be used on my leak down tester. WELL MADE, EXCELLENT VALUE.

I had to get this adapter for my innova compression tester becuase it did not include the size I needed. I’m compression testing 4 stroke dirt bikes which mostly all take a 10mm spark plug and luckily this thing works perfect it even fit perfectly on my innova tester. Not to mention this adapter made it to my doorstep in less than 24 hours with prime “2-day” shipping. Couldn’t be happier

Allows compression testor to thread into cylinders spark plug hole, so compression can be measured on my 2015 Honda MSX125.

If you have a Mac Tools compression testing kit you will need this adapter to check compression on a Honda Crf250. Once I got this tester it worked perfectly.

This is a needed tool as the 10mm adaptor that comes with the kits do not fit some motorcycles, I used this on a 450 Kawasaki and a GSXR old one, the one issue I had was the sharp edge at the top off the threads where the hose fit cut up the sealing o-ring - I did taper the edge - run a tap to clean up rough threads, It's a much needed adaptor if doing leak down or compression tests, I don't use it much but it's a needed tool for sure that everyone needs just for that one time. Find it strange no one said one word about the sharp edge cutting the o ring ... maybe I was just missed on the factory. It's a must have adaptor just the same.

I am using this product to adapt my compression tester to 10mm sparkplug holes. It is exactly as expected and the qiality is excellent.

Fit very well

Glad I was able to buy just one piece instead of a whole kit. Price was fair as I couldn’t find this online anywhere. So I’m satisfied with the seller and the product.