Hitchcocks Forum

Hi Guys.
Further to my query a couple of weeks ago about shimming the cams and idler pinions in my 1996 500cc Classic, I followed up on advice to try Plastiguage. Great stuff but expensive here (its about twice the UK price of GBP11 for 10 sticks).
I found Mr H’s performance cams to have little end float, perhaps 5thou but the idler pinions have 20-25thou end float. Do you think this end float would cause excessive noise? I could take out most of the shims but woudl have to have new ones made as our host only sells the idler pinion thrust washers (PN 140121) which are ~50thou and too thick.
The remainder of the engine noise, most of it, comes I think from the worn rockers which I have still to resolve - easy to replace but hard to explain why they wear out so quickly especially as I have put in the high capacity pumps.
Thanks in advance for your comments.
ChrisD

Hi CHRIS D --------- IMHO 25 thou total float is an awful lot for a pinnion that just has to stay where it is and rotate !!In old money that's almost 1/32" (31 thou)..If you have any contacts with a machine shop and they have a magnetic table on a surface grinder then that's how you could get the oversized ones thinned down.. Remember that you'll have to HALVE the difference to allow for a shimm on both sides of the wheel...I think mine could be near that situation as well (2005 Classic 500).......

5 thou is what you want,you can buy shimming sheet and make your own.Make sure the gears are meshing correctly with negligible backlash.And at least 2 thou valve clearance if you want decent(30,000 miles)out of your rocker blocks,check that the pushrods are making correct contact with the ball end on the rocker,most don't and will cause excess racket.Jack

Glad to hear that you think the idler pinion float is too much. I shall order the relevant 'washers' from our hosts and get them flattened down to ~15thou. You can't use the cam shims because the cam shaft is a different diameter from that of the idler pinion shaft. Wonder that was done?
I'm also interested to know if the megaphone silencer (91009) together with its baffling and reverse cone is quieter than the shorty silencer(91007) which is painfully loud for the rider and the audience.
Cheers
ChrisD