Compression Testing

[Mickly]

I’m in the midst of sorting out my Trophy engine issues & have got to the point of measuring compression.

I have a question about this process -

I have a compression tester & on the 1st cylinder when it first cranks for a few revs the gauge shows 125psi but when immediately cranked again it goes up to 150psi, after that it won’t go any higher, which reading should I be using?

[Bender]

Usually use highest reading but compare with other cylinders. 

[V650]

If the compression tester has a rubber hose connecting it to the sparkplug hole maybe it takes a few seconds pressurise that hose

& following tests the hose is already pressurised 

Any time I have done a compression test on the car it was crank it while cold with the throttle open until the pressure stops increasing  

 

[Mickly]

1 minute ago, V650 said:

If the compression tester has a rubber hose connecting it to the sparkplug hole maybe it takes a few seconds pressurise that hose

& following tests the hose is already pressurised 

Any time I have done a compression test on the car it was crank it while cold with the throttle open until the pressure stops increasing  

 

That’s what I’ve been doing and have got 150 psi on all cylinders so happy days.

[V650]

I would say if you are getting 150 ( 10 bar )  on all 3 your grand 

Edited June 18, 2022 by V650

[Mickly]

1 minute ago, V650 said:

I would say if you are getting 150 ( 10 bar )  on all 3 i'd say your grand 

All 4 … it’s a 1200 Triumph Trophy, I’m really chuffed.

[Mississippi Bullfrog]

Well done that man.