Previous owner rebuilt motor and removed heater - heat exchangers in lieu of a drive different exhaust / muffler combo. They had some heavy duty duct tape and tie wraps on on the (2) ports off the fan shroud. Those have worn off and now fallen off.

1 - it seems like I would want to keep these blocked off to help with cooling / air flow

2 - is there a more elegant way to block them off other than duct tape.

Thanks.

It is better to leave them open. Blocking them off disrupts air flow in the shroud by blowing air into a dead end. In normal operation they are blowing air through the heat exchangers even when the heat is off. If it really bothers you take the shroud apart and block the openings inside the shroud. Maybe fill the holes with expanding foam.

Are the J tube holes in the cylinder tin blocked off? I made up sets of plates to cover those holes as they allow hot air from below to be sucked in.

@mct911

Yeah. I blocked those holes off with some sheet metal. They were open when I got it and I was getting some high CHT readings. Thanks! Appreciate the help