The Chronicles of Sled

In my earlier blog entry about keeping a good supply of lube I showed what happens to the cam bushes when they don't get lubricated properly. At the time I had plenty of spares that were still well within service limits so I was not too concerned about the same problem arising.

I did another set in running a cam that had slightly worn journals, I should've taken more time to measure them but as they say coulda, shoulda, woulda...

So I took a visit to the local Honda dealer (the absolute last resort for someone like me) and found out that new parts were available for around $70.00 ex Japan each. Blow that for game of soldiers, $140.00 is the equivalent to four days entry fees at the Slipway!

So after some research I decided to bite the bullet and machine some myself.
I contacted Mico metals and got a 250mm long section of cored (19 i.d. 32 o.d) LG2 phosphor bronze for about three quarters of the price of one of the Honda bushes.

The bushes themselves are relatively simple and the bronze machines really nicely. The only tricky(ish) part was machining the oil groove (see the tool I altered below) to the inside and pressing the locator pin/oil way into the finished bush. I didn't make the pins I just destroyed the old worn bushes and reused them.

So I machined them to the closest clearance specified in the manual and checked the cam journal to make sure it was ok this time.

Everything checked out so I assembled the motor and gave them a try. They seem to be holding up well so far as I've done five or six meetings and they're showing no sign of measurable wear.

They look flash too, pity they're hidden inside the engine!


New versus old bushes, note the oil groove inside.


New bushes installed on cam, in cylinder head.


Oil groove maching tool, reground internal thread cutting tool.