Re: [DML] Re: Back to Basics?

[Don Ekhoff <ekhoff@xxxx>]

I have seen several examples of minor damage from an engine backfire 
that might be worth checking. There is a slender steel bar covering the 
air metering flap door under the air cleaner assembly. This bar has a 
rubber bumper and is intended to restrict upward movement of the round 
disk underneath. If a backfire has occured the internal pressure will 
"blast" the disk outward and bend the bar. This then allows the disk to 
become sticky as it can wedge into the housing. I have found that a 
gentle hammer blow to the bar will bring it back staight again. Just 
somethng to look for.

Don Ekhoff
Vin 6543



content22207 wrote:

> An honest to goodness backfire (vs muffler explosion) can be an eye
> opener. Nothing quite like fire shooting out top of your
> carburetor/upper air assembly/whatever. Is caused by spark when intake
> valve still open. Allows fuel mixture to ignite backwards to metering
> device.
>
> Go back to first pulley mark before eyebrows burn off.
>
> Muffler explosions are altogether different. Are caused by unburned
> fuel igniting in hot exhaust system.
>
> Bill Robertson
> #5939