Topic: CB500 REBUILD...4 PISTONS, 2 LENGTHS/HEIGHTS

[jackhammer50]

I was about to install my new pistons when I notice they were not all the same length.  Two are a little bit longer than the rest.  There is a tab on the skirt on the longer pistons that is not on the other two.   These are all Honda NOS pistons with the same part number: 13103-323-000.   

Do you think this will matter?   If so, can I just grind this tab off?  If I remove it, they will all be the same length.

I have a set of Rocky pistons as well and they all have the tabs too.

What do you think I should do?

Thanks,

Jack

[Trad]

I'd just leave them alone and run them like that. Just verify they are the same weight and diameter.

[bwaller]

Do they both have "323" in the piston side relief? I just checked the 500/550 pistons here and they're all the shorter skirt type. If you install a pin between the two is the compression height the same between the two? Check that the longer skirt clears the crankshaft at the bottom of the stroke. I'm no 500 expert, but the final three digits "000" in the part # usually means OEM, but obviously not.

If you bought them at a dealer take them back. It's unlikely the weights are identical. One type or the other, I'd want four the same.

[jackhammer50]

They all have the "323" on them.  But, the shorter pistons are "323 4" and the longer ones are "323 2".

The distance from the wrist pins to the top of the pistons are the same. the weights are all identical; 119 gms.

[Trad]

I thought they were the same part number. If they are different then take them back for sure as bawler said. It's a faster and easier solution than verifying all the specs and possibly having to modify them.