false compression readings ? Help

[stihltech]

No need for a compression tester on a saw. Use starter handle method and visual parts diagnosis. Very important to diagnose a saw.

 

[heimannm]

I believe the ones with the white ring are the low pressure ones, at least the Snap On ones I bought had the white ring.

https://www.summitracing.com/parts/...SuAXrEX5AZw3Rw6PyFaRJX3vw2DzSNYBoCGR0QAvD_BwE
I couldn't find a link to the Snap On one in a couple of clicks...

Mark

 

[Woody912]

You may have also purchased an automotive compression tester that has the check valve at the gauge, and not at the tester end. Those types will tend to test lower on small engines.

yep, I bought the wrong one. Tests 120 psi on a good running saw

 

[RedneckChainsawRepair]

Small engine tester from a bigger set was like 22 shipped.

Valve at bottom at cylinder. TU22 or something like that.

 

[JoeMay]

EH?

I believe WTFO = with throttle fully open.

 

[Chevboy0167]

^^^^ Or as AvE would say, What The F**k... Over!

 

[Husky77]

My 550xpg was reading 55psi other saws over 100psi. Yet it was running fine, tried it with a friends expensive gauge and guess what...... over 155psi.
You get what you pay for, dont expect accurate readings from a budget tool, whatever it is.

 

[Bforeman]

I believe WTFO = with throttle fully open.

Wide the f__k open

 

[Mad Professor]

I have a new pittsburgh comp tester from harbor freight. i'm not impressed. everything tests at 40 psi including my good running saws. do i need to return it or am i missing some trick

Stop buying pieces of turd. From the country that gave us Kung Flu

 

[old guy]

I get the same reading, open throttle or closed.

 

[Homer6679]

I’ve had good luck with the Maddox kit from harbor freight. Definitely not the best quality but it has a bunch of adapters and seems to have consistent results

 

[JoeMay]

I get the same reading, open throttle or closed.

Thank you.

 

[lone wolf]

Thank you.

Yup don't worry about it. But you will get a slightly different read cold and warm. only a few points 3-5 maybe.

 

[AlotL1keVegas]

Make sure your holding the throttle wide open to get an accurate compression reading. Also, keep pulling the engine over until the compression gauge doesn't move anymore.

 

[thenne1713]

I have a new pittsburgh comp tester from harbor freight. i'm not impressed. everything tests at 40 psi including my good running saws. do i need to return it or am i missing some trick

EXCHANGE IT, something bad'

 

[Automender]

Since the exhaust port is above the intake port and most two cycle don't have valves is it really important to do wide open throttle. The only time the charge is compressed is the time of travel from the exhaust to the squish ring. Four cycles need the throttle wide open.

 

[lone wolf]

Wide open throttle

 

[lone wolf]

Closed throttle.

 

[Bill G]

EXCHANGE IT, something bad'

Yes it starts with a C and ends with an A

 

[Bill G]

Take it back and buy a Matco, Snap-on, etc. Spend 20 bucks, once.

Where are you buying a Snap-on or Matco compression testers for $20? Heck two weeks ago my son and I took off to get some tire chains. He had a pair of Snap-On socks sitting on the dash. He said they were a Christmas present from the Snap-on salesman. I bet you if they were selling the socks they would be $30 or more. Show us where you are getting a Snap-on or Matco compression tester for $20.


https://shop.snapon.com/product/Compression-Gauge-Sets/Automotive-Compression-Test-Set/EEPV500