gap

[Nurse Julie]

Correct, that's what the Honda charts show - piston size and bore size, the mean difference being .025mm (.001"). That's the dimension  Murdock asked for  with his original drawing. But as has been pointed out, check with Cruzzing, are they happy with that clearance for their particular piston material ?

Hope Murdock has stopped scratching his head now after all this up and down (side to side ?) discussion !

Now, let's start again with ring gaps !!!!

Having rebored well over 100 SOHC/4's using Cruzinimage piston / ring kits, (well, not me personally but Graham (Trigger) , I just make the tea ☺️) I can confirm the clearance we are talking about is correct.

[murdock]

Jua jua ..

[murdock]

They have arrived!

[Erny]

Just for couriosity, can you weight them? Interested what are weight diff piston to piston (if you have such scale)

I'm currently working on old Jawa 350 engine (2 stroke, 2 cyl) and had quite big difference between 2 pistons (7 grams on 200g piston)

[murdock]

Weights are in grams, cruzing pistons are + 0.50

[murdock]

I have already delivered cylinders and pistons to the machinist who accepted the 0.0254 mm without hesitation, I hope it goes well,
Could someone now give me advice on the first break-in or start-up, I know it as softening the engine, so that everything settles

[Bryanj]

Ride it normallyand change the oil and filter before using then at 500 miles then every 1500.
Check tappets at 500 then every 3000

[murdock]

OK, thank you