60 Evinrude 40 wont run with cover on

" I have been running this old

" I have been running this old engine in a garbage can and the thing runs fantastic until I put the cover on.I have been adjusting the carb and it idles smooth and accelerates hard until I put the cover on the engine .Then the rpms slow down considerably,If I open the door on the cover it runs a little better but if I close it seems to choke and slows considerably.I know cars run better when they have more air available to the breather,but this is made to run with the cover on and closed .Does anyone have any ideas?Thanks in advance for any help.Mike "

Had a error here. Actual reply

Had a error here. Actual reply below:

"Mike..... When you put the ho

"Mike..... When you put the hood on the engine, and have it running in a garage can, the exhaust fumes get trapped under the lower hood pan. There is a air intake in the lower pan and the air rushing through the carburetor draws its air from that intake. However in a garage can with the hood on, the carburetor is drawing almost pure exhaust fumes right out of that can. Obviously no engine can run on that.... and the rpms drop very quickly. It will be a different story on the boat as those fumes will dissipate rapidly and move away from that intake.

Joe "

" Thanks again Joe ,I see the

" Thanks again Joe ,I see the intake hole on the bottom of the case now.Can it get any more simple ?Mike "