Air cooled engine temperature

[camelotr]

Hi.

I am running in an air cooled 4t bike. I m monitoring the AFR and the engine temp, and would like to know what engine temps is the advisable maximum for running in to keep safe?

[camelotr]

Thanks Dave!,

At the beginning of the running in I saw 110-115 degrees on the cylinder head, and at the plug area. Now I can see 100-105, but with outside tepmperature at 0-5 degrees (yes it is a bike, me myself tend to feel overcooled after a very short time :-) ).

I never ran in aircooled engine, I am experimenting on this bike before I build something much bigger and much more costy :-).

[camelotr]

Thanks Dave, I am feeling statisfied with the way life goes. After our very good learning session on thoose Mini engine, I did not have any misserable experiences with engines. I am doing the same as a few years ago, although on some more complicated and more expensive cars and of course this little Yamaha, but this is my runabout/victim for learning how to live with/modify injected systems.

[camelotr]

No.

Finally I could contact a guy from the piston manufacturers, who showed me the original drawings and the factory recommendations for the piston (4thou clearance), and told me that this is the official factory and manufacturer recommendation. But he also shared me his opinion as a engineer, and after that we decided to go for a weak 3thou (0.065-0.07mms). The engine was not yet assembled, soo I dont know if it was a good decision or not - yet :-).

[camelotr]

One more question with the bike. Its air cooled, but injected with a catalytic converter. What kind of AFR should we prefer to keep the cylinder head temp at bay, but also not to do harm to the cat?