73 Z1 COMPRESSION VALUES

[MaineKZ]

What's the range of acceptable compression values for a 73? What should I be expecting best case? ta

[chrisu]

my factory manual says 145 std and with a service limit of 100. Thats lbs/sq in.

less that 14lbs/sq in between cylinders.

hot engine - throttle WFO.


HTH.............Chris

[MaineKZ]

thanks Bud. Wouldn't you just know it - my engine ain't running at the moment

Is there any point in testing compression on a cold engine? I guess it would still show if any pot was significantly under par.....

[chrisu]

it'll show if they're wide apart.

do it and note the numbers.

then put a small amount of oil down each bore and repeat - if it goes up a lot then bore possibly suspect.

[RALPHARAMA]

After talking to those who really know their onions eg Steve Debben, apparently compression tests aren't all their cracked up to be, and often give false readings. My bike was smoking like a bastard and drinking half a litre of oil for every tankful of motion lotion, yet had really good results from the compression tests. Apparently a better test is the 'dropdown' test where you essentially put some compressed air into the cylinder and how much escaprtes over a specific time gives you an idea of what condition the engine is in. I fully intend to make up a rig for this test myself

[Mick D]

Hi Chris, I'll check to see if we have a leakdown tester at work. Let you know, if we have I'll blag it this weekend.

Mick

[MaineKZ]

Cheers Mick.
Don't bust a gut for this weekend - I'm a while away from starting on the Zed - just getting my ducks lined up.
But if you do find one, then mark me down for a loan at some point.