[Nedster]

Hi, I've just stripped the top end off my 1976 CB 360 G5 to try and find the cause of smoking. A few issues I've found but what I want to no is how do I tell if the pistons are standard size or if it's been rebored at some point. I can't find any markings on the Pistons themselves other than the make which is Art. Also a no. 5 next to the direction arrow on the skirt. Can anyone shed any light on this please.

Thanks Paul

 

[Skyliner]

If it is a Standard Piston then there will be no markings on it. If it is oversize then there will be a number (0.25, 0.50, 0.75, 1.00) stamped into the dome as if the arrow is pointing at it. Look closer, your 5 could be part of one of these oversize numbers. Also the rings will be stamped with the oversize on the top next to the gap.

 

[Nedster]

If it is a Standard Piston then there will be no markings on it. If it is oversize then there will be a number (0.25, 0.50, 0.75, 1.00) stamped into the dome as if the arrow is pointing at it. Look closer, your 5 could be part of one of these oversize numbers. Also the rings will be stamped with the oversize on the top next to the gap. View attachment 195826

Thanks! That's very useful. I think mine must be standard size. The only markings on mine are on the skirt so are probably nothing to do with the sizeing.
What is the maximum ring gap when measured in the bores before needing a rebore?

 

[frogman79]

Shop manual can be had here

http://74.113.168.218/manuals/360/Honda_CB250_CB360_CL360_CJ250T_CJ360T_Shop_Manual.pdf


All the information you should require or your machinist will need for an overbore should you have to will be in there.

 

[Nedster]

Shop manual can be had here

http://74.113.168.218/manuals/360/Honda_CB250_CB360_CL360_CJ250T_CJ360T_Shop_Manual.pdf


All the information you should require or your machinist will need for an overbore should you have to will be in there.

Thanks! That's really useful?