Before I resort to buying all the cheap rockers I can, and after mulling over everyone’s help, experiences and thoughts in my original rockers thread a decision was made to try out the Newman cams fix. My reasoning being 11 years Experience with this bike has taught me that rockers flake. It taught me good second hand rockers can and have flaked. It taught me the later style “fixed” rockers can and have flaked. Also openers/closers, inlet or exhaust, horizontal or vertical my engine’s not fussy what it eats, some years its hungry and others not hungry at all. As the valves needed to be reground in any case this would mean a reshim from scratch, both time consuming and expensive but would have to be done either way. Bizarrely I think that might even be a future saving if I do the rockers now…not sure I believe it but it makes me feel better. So if anyone is faced with the same dilemma (I hope not) this is what £45.00 inc vat per rocker looks like…
Just sent some off in the post to Newman yesterday. Can't stretch to getting the whole lot done unfortunately. Out of curiosity what time would be spent on a full re-shim? I ask as a dealer out where i live charges 90 euro per hour labour, BUT all shims are replaced free of charge, you only pay for labour, but i don't want to be stung on the hours spent.
I have done all the decoking and lapping in, just wondering how long it would roughly take to be presented with heads with everything back in and just needing all shims checked and swapped over if needed. Saying that i have been doing some playing about with it this afternoon and will probably do it all myself.
Keith, yes that’s what Newman cams refinishing looks like and it will be interesting to see how they last. Red, not for me. Doogalman, I’m told re-shim from scratch will be about 3 hours but can be more, just depends how it falls, and no charge for shims if exchanged. The problem when shimming all from scratch is the amount of shims you need to hand. Another little job while the barrels were off was to plug the crank case oil feed to the vertical pot. A leak waiting to happen I think. Just waiting for the heads to come back and all I have to do is get it back together with no bits left on the bench.
Is your problem behind the breather? If it is it's probably the o ring that's let you down.If you look at the underside of the barrel you will see this oil feed doesn't go any where and is a throw back to older motors I'm told. I don't know why it has been machined but been advised to make a plug a tap it home. It's a bit odd as the horizontal one is left blank.
Had some done by Dave Newman Cams, on my ST4 a few years back due to the same old 'flaky chrome' issue you've been experiencing. Rich at Louigi Moto had a big cardboard box under a bench, full of scrap Desmo Quattro rockers that he'd previously replaced! After he'd given a couple of companies a go at 're-chroming' them and been disappointed with the results (as you've been), he's changed to having them done by Newman Cams. Mine had another 6k miles put on them and looked like new, before I was forced to sell the bike :-( FWIW, the only thing I would advise is to replace them in pairs e.g. both inlets/both exhausts, as until I did that I experienced some high frequency vibes through the footrests. Rich put this down to the refurbished rockers having a subtly different profile to the originals, which messed up the fueling slightly and set up a very slight imbalance between the cylinders.
I've had Newman opener rockers in my 916 for 3-4yrs now and along with MBP collets the valvetrain has been spot-on. Previously had 9 openers flake but since 'Newmanising' I've had no 'glitter' in the oil and only one shim change (at recent service) and even that was still well within tolerance and I only changed it for OCD reasons. I still have the original closers in there and they're still fine after 47k miles. As for the vertical cylinder oil feed, when I first had the heads off I replaced the gaskets with the later style (thinner head, thicker base) but didn't fit the required thicker 'O' ring to the oil feed (because it was missing from the gasket kit). On startup oil pissed out so I took it apart and tapped/plugged/loctited the feed hole (M5 IIRC), fitted the thicker 'O' ring and filled the void with threebond - it doesn't leak any more...
