Today, a member asked which way did the pistons go back in the bores.
He had bought the bike in boxes and the PO had not marked them and apart from the fact that they were real odd balls,
3 valve reliefs on one side and one on the other, there was no little arrow on top pointing forward.
Of all the CB750 pistons I have seen, the stock ones have a central inlet cut away and two small exhaust cut aways either side of the centre. This is to allow the piston to be fitted in either #1 or #2 cylinders.
Other pistons like JE or the old RC ones come as a handed pair that requires them to be fitted in the correct cylinder, look in your cylinder head at the way the valves are placed and you will get he picture.
Wiseco 836 pistons come with the cutaways centrally in line. These can be fitted in any cylinder as the reliefs are large enough to accommodate the off set valves.
OK, you have a set of pistons with no little arrow telling you which way they go in.
In most cases, the exhaust relief/cutaway is usually bigger but another way to tell is the piston pin.
In most Honda motors, the piston pin is not through the centre of the piston, they are usually off set to the rear of the piston. It can be from 1 to 3mm and this offset is allways to the rear of the piston.
I hope this might be of some use to newbies or someone that buys a box full of unmarked parts.
Sam.
