Best compression tester for small engines?

[FergusonTO35]

So, I have a really nice Matco compression tester for auto engines however it seems to read small engines low. I'm thinking that chainsaws and weedeaters dont really move enough air volume for accurate readings with an automotive tester. The long rubber hose between the gauge and the engine probably doesnt help. For example, my Echo GT-200R which runs awesome and really doesnt have that many hours blows 80. My Poulan BC2400 that I just rebuilt blows 60. This has always been typical, dont think ive ever seen a small engine with more than 100 on an auto gauge.

So, what is a really good compression tester for small engines, specifically under 100 cc?

 

[Kiwioilboiler]

I'm in. Just bought an Ampro universal ~$20 usd, looks like fellow NZer @markds2 has one too. Haven't checked it against a reference source but worn 359 110psi, used 372 130psi and used 288 150psi are all readings not outside the realms of possibility.

Matco is pretty good gear i thought, i'm sure the hose is rated to not expand unnecessarily. What about spinning them over with a power tool via the flywheel, in case its speed of air delivery that's introducing any error?

 

[cuinrearview]

The compression testers for small two strokes need to have a shrader type valve at the very end of the hose. This eliminates the above mentioned extra volume in the hose and gauge. You may be able to find a fitting for your Matco.

 

[Xr650jkallen]

I have a Mityvac one like this and it's been great. It's very well built, and it does have the schrader valve.
https://www.oreillyauto.com/detail/...0/mityvac-compression-test-kit/mv5520/4534300

 

[FergusonTO35]

Thanks so much, I'll check it out. My Matco does not have a Schrader valve on the bottom, I know that.

 

[Lightning Performance]

I love the push in short job for electric starters. Found another old one just like it with a 300 psi gauge made on it. If the pipe is cut and an old plug or oil fouler is welded on it is about as short as possible. They both have Schrader valves in the end.

 

[FergusonTO35]

This is my kit:

https://www.matcotools.com/catalog/product/MCVK/COMPRESSION-VACUUM-AND-FUEL-PUMP-TESTER-COMBO-SET

I sent Matco a message explaining what I need, asking if they have any adapters suitable for small engines.

 

[Kiwioilboiler]

This is my kit:

https://www.matcotools.com/catalog/product/MCVK/COMPRESSION-VACUUM-AND-FUEL-PUMP-TESTER-COMBO-SET

I sent Matco a message explaining what I need, asking if they have any adapters suitable for small engines.

How did you get on with this Fergy?

 

[FergusonTO35]

They never responded. I'll probably buy the Echo OEM tool at some point, I have their vacuum test tool already.

 

[backhoelover]

I like echo compression tester can be bought for around 70.00 dollars

 

[backhoelover]

91147 is part number for echo test come with 14-10mm adapter also.

 

[FergusonTO35]

Thanks!

 

[I Know Something]

I see ones like this and keep thinking about it. I'm just unsure what one to get.



Edit: apparently Amazon links don't work. Lol. It's an OTC brand one.

 

[AVB]

Here I am using an Actron CP7828A setup. It does have the Schrader valve at the end of the hose. The newer version does have a extra long reach ridge 14mm adapter and a 18mm long reach is available for it but I haven't seen a 18mm plug hole yet.

 

[greendohn]

I've gotta' Snap On compression tester that reads low on small 2 stroke engines.
I've wondered what's up with the low readings, the small volume of air from a chainsaw would make sense.

Now I know.

 

[Egg Shooter]

91147 is part number for echo test come with 14-10mm adapter also.

I use this one. Recommended by a fella on ope that is a small engine mechanic. Works well.

 

[Larry B]

Both of these read correctly without using an adapter. If i add an adapter it lowers the reading on both.
Chineeseium clone 660.

 

[Egg Shooter]

View attachment 265538 View attachment 265539
Both of these read correctly without using an adapter. If i add an adapter it lowers the reading on both. View attachment 265540
Chineeseium clone 660.

The Echo unit has a schrader valve in both the ends. I've experinced no low readings.

 

[Egg Shooter]

This MM ported saw read 80 psi with a schraderless adapter on a different gauge. The pic below is with the Echo unit and the included Echo 10mm adapter with schrader valve.

 

[Larry B]

This MM ported saw read 80 psi with a schraderless adapter on a different gauge. The pic below is with the Echo unit and the included Echo 10mm adapter with schrader valve.
View attachment 265552

You break any recoils on that thing?