Whats the correct way to test your compression,(i have a compression tester) and what is a good reading for a 1275cc engine.

shove it in a spark plug hole, and turn the engine over by putting a spanner across the starter solenoid terminals

'good' is probably anywhere above 130psi - but the main thing is that they're all the same

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did I tell you that I won a trophy?

Gangsta method!

With the gauge you press against the plug hole I have someone else turn the motor over for me, but I've now got a gauge you screw in, so I can do this myself

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Simon

The adventures of an owner builder in the Tallarook Ranges

Just make sure the mini is in neutral and put some decent wheel choc's in front of as many wheels as you can for extra security .

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I always do compression test with the coil disconnected and the throttle wide open.

Just my system, dunno if there are good reasons, obviously ignition will not work, ( of course all the plugs are out anyway!) and perhaps less chance of stressing carb butterflies, allowing air in etc......

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Sir Alec! we are not worthy!

To get an accurate reading the throttle must be wide open & all plugs out, otherwise it will read lower.

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Too many cars, and too little time.

cool ... ive been doing it right then... i think im getting bout 150+ each cylinder with all plugs out and throttle closed... cylinder 1 is slightly less..

Its a good relative test, actual numbers will shift depending on the cam and compression ratio....but as long as you do it the same each time you can get an idea of where your mini is at.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

ok... ill give it a test this weekend with the throttle open ect... post how its goes lol
cheers guys

it would also be a good piece of advice for some, to check its in neutral

I know some who have learnt the hard way, lol including myself, haha.

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Bluey-1973 Clubby - 1330, high lift, big cam, 7 port madness in progress..

Gumby-1978 Minivan, British Racing Green - 1310, high lift, mild cam, enlarged porting and chamber shape with big valve head, supercharged build in ever slow progress!