Gpz550 20 thou out of the hole

I got my cylinder block back from my machinist and he had to skim 0.016 off the deck to remove a low spot between no1 and 2 cylinders. I think it had been machined before i got it.
Without a base gasket the pistons are 40 thou above deck.
Base gasket should be 0.020
Is it safe to skim the pistons 0.020
The numbers are rounded as I've converted from metric

Don't touch the pistons..
What spec is the engine, are the pistons stock.
The head gasket should be 40 thou = 1mm compressed.
So that leaves a 1/2 mill of squish with the base gasket fitted which is too tight.
The best solution is probably to use two base gaskets to get the 1mm clearance.
Best to test assemble the top end and use some soft solder to check the squish clearance before running.

I haven't touched the pistons other than fondle them :ohmy:
I was not to sure about stacking base gaskets or what is max recommended base gasket thickness hence the piston machining question .

I stuffed up the conversions a bit when using my phone. When i got home i rechecked my notes
The piston is 0.84mm or 0.033" above deck
If i subtract 1mm base gaskets and i end up with 0.16mm below deck
The head gasket is advertised as 0.043" (1.09mm) so i will end up with 1.25mm, 0.049"squish
I was told by the guy who did the machining it would be fine if i aimed for 40 thou

Also in my notes i notice the original pistons where already sticking out of the block when i dismantled it, but didnt pay much attention to it othe than jot down a measurement.
The engine will have 615 pistons, 84 GPZ cams, 4-1 exhaust and i plan to fit some larger later model cv30 carbs down the road
So i dont really want to throw away any free hp if i can help it, i was going to whittle them down myself :whistle:

If the head gasket is 1.09mm compressed and a 0.5mm base gasket you will end up with 0.75 mm of squish or 29.5 thou which should be ok.
Just need to check valve to piston clearance when you fit those GPZ cams.

Sweet! 29.5 thou it is Thanks Zed

I will definitely be checking the valve clearances once i get the head back from the shop,