Valve adjusting

[trolle]

As I was a little dissatisfied with the fuel economy of my new carbs even after finetuning, I checked my valve settings and found that all four valves had receded 0.1 mm since the last adjustment 5K miles ago.

They are now adjusted to the proper settings: 0.2 mm on the exhaust side and 0.1 mm on the intake, and the engine runs much smoother.

Question: Is 0.1 mm an acceptable change over 5K miles?

greetings from a semi sunny north

[nhmaf]

IT may be acceptable, especially if the heads have been pulled/replaced recently or the cylnders taken off and you hadn't checked the clearances in that 5K mile period.   I would keep an eye on it though, and check it again after another 2K miles and see if they have stayed put or are continuing to lose clearance.