compression testers

[jgflawn]

Cool new thread..thanks!!!

I'm using an OTC5606 compression tester. Quite nice to use, simple to operate. Seems very accurate so far, and had some very good reviews on the net. Comes in a very nice plastic case with repair kit included. One actually said that it is basically a MAC with a blue face instead of red (I know, can't believe everything you read). Only $80 cdn. and looked considerably better than Princess Auto (think H.F.) and Canadian Tire. Purchased from Babco on the West Coast online.

[bgsengine]

One actually said that it is basically a MAC with a blue face instead of red (I know, can't believe everything you read).

They would be correct - the other way around.

OTC - Owatonna Tool Company Builds special service tools for many manufacturers, including Ford, GM, Mopar, as well as a supplier of units for MAC TOOLS branded tools.

So if they had said, "Mac Tools Compression Gauge is just an OTC in Pretty Red Packaging" they'd have been exactly right.

That said...

Automotive compression testers while useful, will not necessarily be the best tool to use on a 4-cycle engine (You get much more information on engine condition doing a leak-down test) but still compression is a reasonable check to make.. BUT , on a 2-stroke small displacement (trimmers, saws. etc) that are "marginal" using an automotive tester (Unless you have a *SHORT* - 5 inch - hose for the gauge) may result in condemning as bad, an otherwise serviceable engine. - The long hose on most automotive gauges can result in inaccurate readings by as much as 20% due to the *volume* of the hose being greater than the engine's displacement!
- So , when choosing a compression gauge, try to make sure you get one that you can get a short adapter hose (and better yet, different size spark plug adapters - 10mm, 12mm, 14mm and 18mm ) in addition, and you'd have th eonly compression gauge set you'll ever need.

[jgflawn]

thanks for the correction regarding 'face cover'. it does sound more like it....

Thanks for the info on hose length as well...I'll have to check my set and see whether one is available for the little Husqy trimmer I need to work on.

I agree with the comment about leak-down testers as well, being overall better investment for 4 stroke, but I'm (at the moment) only into 2 stroke work (on my own stuff - not commercially). But it is on my list of things to add before I do my first 4 stroke later this year if all goes well.

[pie eater]

i too like otc tools. i work for a large john deere main dealers, and we have some specialist tools that come with john deere part # (jdg) and there either made by otc, or kd tools.
i have the otc leak down tester and it works really well.
but before i hijack the thread, i also have got a set of INNOVA 3618 Adapters for Compression Testers and fitter them with male pipe thread adapters, so i can screw them into the plug hole of 2 cycle, and use the mityvac to do a vac/pressure test,on the seals ect.

[RoyM]

I have a compression gauge I bought in the distant past and seldom used for the reasons Brian outlined. It simply was not useful for small engines. It is getting pretty beat up from years of being banged around in the tool box.

[Joel_53]

Well described OTC5606 features..

[Mek-a-nik]

I have the Echo comp tester. I bought it from Brian. It's easy to use and provides an initial clue of what's going on. It is better served using on 2 strokes. A leak tester is better for 4 strokes.