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Engine basics => Engine set up tips => Topic started by: Leandro_Foltran on June 29, 2025, 04:05:00 PM

Title: PA 40
Post by: Leandro_Foltran on June 29, 2025, 04:05:00 PM

Hi !
Bought one second hand PA40 from a friend of mine.
It comes with tree head shim on cylinder head:
0.008 inch 0.21mm
00075 inch 0.19mm
0.003 inch 0.07mm
This is ok ?
What”s the standart/initial head shim configuration ?
Thanks
Leandro

Title: Re: PA 40
Post by: Motorman on June 30, 2025, 08:09:47 AM

How was your friend using it? Just try it and see how it runs.

Title: Re: PA 40
Post by: Brett Buck on June 30, 2025, 11:06:34 AM

Quote from: Leandro_Foltran on June 29, 2025, 04:05:00 PM

Hi !
Bought one second hand PA40 from a friend of mine.
It comes with tree head shim on cylinder head:
0.008 inch 0.21mm
00075 inch 0.19mm
0.003 inch 0.07mm
This is ok ?
What”s the standart/initial head shim configuration ?
Thanks
Leandro

   I don't recall what I was using, it was a long time ago, and I was never too happy with my setup. My *guess* is to start with about .023-.025 of piston/head clearance. Even something as beautifully made as a PA, you need to actually measure it, rather than count up gaskets.

    Also, I think your 0.0075 is a nominal .008 - I think there were only ever .003, .005, and .008  gaskets. Measuring to 5/10000s is a tricky business.

      Brett