Compression tester

[Chris Edgar]

Bought a compression tester on e-bay, cost £9.29

Arrived eventually & looked good but didn't work, which I put down to a possible missing rubber washer in the sliding connection.
PM'd the seller & they said they'd send the missing part. But no, a whole new kit arrived.
That doesn't work either
only goes up to around 30 - 40 psi on both cars engines!

beware cheap compression testers seem to be the answer.

Wonder if anyone else has had similar experience?

Chris

[mike.perry]

Mine works fine, it screws into the plug hole thread.

[Chris Edgar]

Lucky you , Mike

I tried that & it still didn't work!

[bmcecosse]

Hard to believe........ Are you using it correctly ? You must have the engine hot - after a good run is ideal - take ALL the plugs out - screw the tester firmly into the first spark plug hole, enough to get a good seal - hold the throttle open (a brick is ideal) - and crank the engine over for ~ 5 seconds. It should read ~ 160 psi or 10 to 11 bar if it's metric. There should be a little 'release' button that you press - before moving on to the next plug hole.

[Chris Edgar]

I have used compression testers years ago, so I know what needs to be done.
Alas, that tester was lent out ages back, never returned & can't remember who it went to.
Funny how often that's happened!

Anyway, I can only get readings of about 30-35 psi / cylinder on the engines of BOTH cars, so it's clearly nonsense.

My son has said he will lend me one when he comes visiting on Wednesday but being a very impatient person I may spend a bit more & buy one from a local factors before then.

But if my son lends me his, I may never give it back & in time he'll forget who he lent it to...fat chance!

cheers
Chris

[bmcecosse]

Perhaps your son will be 'lending ' you back your own tester from years ago......

[Chris Edgar]

Well, decided not to wait for my son bringing his.
10/1 he would have forgotten anyway.

Bought a "proper" one, Gunson.

Results show 170 psi dry on each cylinder, so ends the bee in my bonnet that there may have been burnt valves, seats or whatever

[bmcecosse]

That's a good pressure - your engine is fine !

[Chris Edgar]

Yes it is, very pleased
I am aware though, that the engine seems to have lost some Zip since we got the car in July.
I need to look elsewhere....carburettor overhaul (it is an HS4) maybe
& replace the dizzy with new one from accuspark, connecting a vacuum pipe to the carb

[bmcecosse]

Don't worry about 'carb overhaul' - but do make sure it makes full throttle when the pedal is on the floor (but NOT before!) and the npiston is rising falling freely - and going all the way up. Use 3 in 1 oil in it. Working vacuum unit will help.