Been trawling through my engine parts for the three engines I am building CB750K0, CB250K0 & CB350K1
It appears that the camchain, slipper and large camchain roller are the same on all three bikes! However, I only have one NOS camchain tensioner arm for the twins and one NOS and one almost NOS arm for the 750. The twin one is very expensive (60 quid almost plus post).
So my question is has anyone swapped the rollers over from the 300 part to the 286 part ( if they are indeed the same ...the roller on the twins is 21.8mm dia.
Another alternative is to machine one in Acetal (Delrin) which is what the race guys do ...but do you need the compliance of the rubber part?
Don't really want to shell out sixty quid for an arm. But there again I don't want to trash the 300 part only to find it won't work on the twin. I do have a small lathe/mill so no problem making smallish parts.
Here are the bits in question:
http://www.davidsilverspares.co.uk/CB750K0-FOUR-1969-1970/part_7591/http://www.davidsilverspares.co.uk/CB250K0-SUPER-SPORT-1968---1969/part_2314/Also asked the same question on the HondaTwins site.
Ash