Quick Easy Question About Finish Sanding A Head

[yuckfoo]

My squish is terribly high and I need to sand the head and get a thinner head gasket. My question is what kind of finish do I want on the head, or, more specifically, what grit sandpaper should I use for the finish. I'll be starting with 60 grit. I'm guessing I don' want a highly polished surface for the gaskets to work correctly.

 

[HumanPerson]

Resurface Cyl Deck

Wax on, wax off! Best done by hand.

motoredbikes.com

Good start at end of page 3

 

[Wrench]

My squish is terribly high and I need to sand the head and get a thinner head gasket. My question is what kind of finish do I want on the head, or, more specifically, what grit sandpaper should I use for the finish. I'll be starting with 60 grit. I'm guessing I don' want a highly polished surface for the gaskets to work correctly.

DO not start with 60 grit, I assume you want to take alot of material off.
Use a bench top belt sander with a new 120 belt. Or 120 by hand and sand on plate glass or any known 100% flat surface
When ya get close to your desired depth, Finish by hand with 220 on plate glass.

TIPS:
On final sanding, mark up the sealing surface of the head with a black sharpie pen.
Check your work while sanding and you'll be able to see any low spots. When all the sharpie marks are gone your head is flat.
Always use new sand paper and change it often. you'll probably use 3 sheets Ya wanna keep the sand paper clean and new.
Use a brush and brush off the aluminum dust after about every 25 rubs on the sandpaper.
If ya wrinkle the sandpaper Use a new piece A wrinkle will ruin a flat surface.

BTW 100% flat surface should look like glass when your done. Some guys go for a mirror finish But I just go 220
A rough finish is NO BUENO

One more thing, Do Not use spray adhesive to glue sand paper to plate glass Spray adhesive sprays on uneven and you'll never get a flat surface.
Also do not use water on wet dry sand paper. Ya want to be able to brush off the aluminum dust from Dry sand paper

 

[Wrench]

Use 10" or 12" Peal and Stick on sanding disc sheets. Their way better than sand paper.

 

[selectivefire]

On a 66 cc engine what is thread length of magneto case cover bolts are they 25 mm the thread pitch is m4 x 0.7

 

[Wrench]

On a 66 cc engine what is thread length of magneto case cover bolts are they 25 mm the thread pitch is m4 x 0.7

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