Gas Engines - Maximum Altitude?

Looking for max alt. safe working info for 100cc gas engines?, Thank you

400 feet.

pawnshopmike said:

400 feet.

Click to expand...

Legally.

Thank you for the quick reply, the reason for the Max. Alt. question is that this aircraft will have auto pilot and will fly out of sight, it will require a licenced pilot to operate, I have not had any experience with these smaller "Gas" engines to know their performance parameters, I hope this helps?.
This aircraft has a wingspan of 6 mtrs. with 2 x Pusher 100cc engines.

My home elevation is 825', I fly at two fields, the lower elevation is 1155', the higher is 1700', my engines run the same at each site, considering i run the engines on the ground at home and fly up to 400' (wink, wink) the Walbro carb can easily handle 1300' change in elevation.

In excess of 10,000ft.... Carbureted systems tend not to do well at these altitudes which is why you will generally only see EFI systems deployed at these altitudes.