A5-A8 motors were specified as 0.1 inlet and 0.15 exhaust. Later motors this changed to 0.15 inlet and 0.2 exhaust. Since no part numbers that were relevant changed I can only assume it was done as a preventative measure to avoid risks associated with the tappets riding the cam base circles. Certainly if the newer 2O2 sensor engines are running the roller tappets then a change in clearance would be understandable. With the flat tappet motors I've never had any issues with running 0.1-0.15 even in extreme conditions. It was 38*C here yesterday, that's 100*F in the old money and I had to take my Griso into Canberra to pick up some steering head bearings for a Breva. It ran just fine, even when stuck in a queue of traffic for five minutes, which is more than can be said of the rider who wilted a bit! I've never run mine with bigger gaps than 0.1-0.15. Its expected to be 44*C here today, thats 111*F! If I go anywhere it'll be in an air conditioned car! :evil:
As for interval for checking? I've found that they usually come set wide from the factory and will close up in the first few hundred Kms. I check them before a bike is delivered, I then check them at the first service and suggest to new owners that a check at 5,000km is a good idea but the factory say after the first service every 10,000km is fine. Certainly after the 10,000 service I find it very rare to find that they have changed more than a thou and while you probably could leave them longer than 10,000km I can't see why you would? Adjusting the valves is so simple and easy not doing it would seem to me to be a false economy. Most of my customers are happy to take my advice on the *Extra* interim check when the bike is new and, as I keep saying, I've
NEVER had a cam or tappet failure on any 8V. Is the slightly anal obsession with checking the valve lash relevant? Who knows? But I'm not about to start trying to prove anything by stopping advising it!
Pete
PS. I have a dipstick thermometer in my G8 and as I said the conditions yesterday here were pretty extreme. While I wasn't thrashing the motor my trip to Canberra involves some 35km of riding each way. On the open road, cruising at about 130kph indicated, even in 38 degree heat, the oil temperature remained obstinately at 112-115*C. When I was stuck idling in traffic and stop/starting between lights in the baking sun the oil temperature rose briefly to 140*C where it stabilised and seemed to not want to get any hotter. Within five minutes of getting back up to speed on my return trip the oil temperature has dropped to 112-115*C once more.
While temperatures in the cooling galleries would of been considerably higher than the overall sump temperature I see no reason to worry unduly about 'overheating' the motor. Conditions yesterday were about as *Extreme* as most motors are ever likely to see!
