Had a buddy come by & help me do some work on my '59 445/Duett. He has a compression gauge so we did a reading & this is what we got:
105/110/110/105
My Duett is a B16B (dual SU carbs.) & from what I read on-line "factory" compression is 142-156 PSI.
So, what do these numbers mean?
Thanks!

Hello,

Also check the valve clearances. With decreased clearance some of the valves may not shut tightly hence letting some air out thus reduced compression. Also do what ridesR100RS suggested. I hope your buddy also squirt some oil into the cylinders during the test (i.e. wet compression test).

Redo the test after valve adjustments.

Hope this helps,
Amarin.
1994 940 Bosch LH2.4

All that is important is that they are even. Very even in fact. The number is not so important. Not much chance that they have all worn "low", so the calibration of the testers is questionable.
Which means be pleased with the results.

Thanks Peetz.I think.:)
The car runs well. It's slow, but, it runs well.....
Jim

With the B16 it shouldn't be too slow. Probably just a matter of setting the ignition timing correctly and making sure that you are getting full advance. When right they are on the verge of peppy.

Peppy is a fairly elastic term, but remember he has a Duett, not a PV coupe. The Duetts weigh considerably more than the very light coupes do.
--
'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)

Thanks Peetz, I'll chk. my timing....
Jim

A proper compression check is done with carbs wide open, or totally removed (more accurate yet), so the engine fully breathes. That makes a big differences for an accurate compression test.

Chris in Northern Vermont, '94 945 w/193K