checkng compression

[audijunky]

Hey fellas,
couple quick questions, do you start the motor while doing a compression check or just turn it over with the starter? how many turns do I need to get an accurate reading? THanks

[Erik the Red]

Warm up the engine to operating temp. Unhook all the plug wires from the plugs. Screw in the comp. tester into whichever plug hole you're testing. Hold the throttle at WOT (wide open throttle) while you hold down the starter button until the gauge doesn't increase anymore (usu. takes 4-5 cycles)

Anyone feel free to correct me if I screwed up the process/explaination.

[mro]

TCI

Have heard that TCI does not like being fired without being hooked to plugs,

so......I just disconnect it too.....


mro
btw, engine will crank nicely with all plugs removed.

[audijunky]

Gracias Amigos, but what does holding open the throttle accomplish?
Hey MRO, about your BTW should I pull all the plugs, I need to check all the cylinders anyway?

[underdog57]

If you Don't hold the throttle open , you will not get a good shot of air for a correct reading . The butterflys will not let air in ...
A cold engine , readings are not accurate either ...

Pull all the plugs , it will crank over easier !!

Bob

[mro]

should I pull all the plugs, I need to check all the cylinders anyway

Yup,
much easier on starter motor and will spin faster

what does holding open the throttle accomplish?

allows air to flow in to head unrestricted. Butterfly valves are opened w/throttle "wto".



mro

[audijunky]

And this is why you guys rule. I tell you what this is the best and most informative site I have ever been 2! Anybody know where I can find the jetting guide? I have been to it before but cant find it now. thanks all

[Ken Talbot]

This is probably the article you were looking at:
Denny Zander's jetting recommendations

[HobbyMan]

Can't you just unplug the TCI? I don't think that will affect the starter circuit. Just a thought. The best, in my opinion, compression guages are the ones that screw and and don't release pressure untill you push the button. I used to use the old syle with no pressure release and you had to hold it in place, but now have the craftsman screw in type.