Backdrag air let

[Plainsman]

1976 115 hp modle 1150 serial # 4323752

What is the purpose of the backdrag air jet? I notice when priming the bulb that fuel comes out of it on the bottom carb and I hadn't noticed that before. I did rebuild the carbs over the winter.

 

[Don S]

Re: Backdrag air let

Ok, this might be a slang term that I have never heard of, but what is a backdrag air let

 

[Plainsman]

Re: Backdrag air let

It's what the merc manual calls it Don. I tried posting a pic, but can't, just get the red x. The carb has a tube that connects both sides of the carbs on top, it goes from the top of float chamber to the other side of the carb.
On the side of the float bowl is a brass screw and that is where the fuel comes from.

 

[JUSTINTIME]

Re: Backdrag air let

back draft

 

[Plainsman]

Re: Backdrag air let

My manual is so worn that back drag air JET looked like Let. Sorry for the confusion.

 

[JUSTINTIME]

Re: Backdrag air let

they got rid of that design
i forgot why, but we learned it, i have to check my notes

 

[Plainsman]

Re: Backdrag air let

 

[Clams Canino]

Re: Backdrag air let

If fuel is coming out of it, you are iether pumping the ball too hard or the float valve is misbehaving.

Totally aside from that - shove a BB into the little black hose and disable the backdrag circuit entirly. It was part of an "economizer" feature to save gas at mid range throttle.

The small savings to not justify the added risk of running lean and the resulting melting of pistons.

-W