Unburned fuel

[jim-moffatt]

These motors had a bleeder system with reed valves. All you have to do on rhe RDs etc is recover what comes out of the valves with a hose back to the boat. Just remove the bleeder valve cover. Block the passage to the leg and add a nipple to the cover to recover the fuel. Very quick and simple.

[vintin]

quote Jim Moffatt:

These motors had a bleeder system with reed valves. All you have to do on rhe RDs etc is recover what comes out of the valves with a hose back to the boat. Just remove the bleeder valve cover. Block the passage to the leg and add a nipple to the cover to recover the fuel. Very quick and simple.

I go a step further on my 57 35hp Johnson. After the condensed fuel is pushed to a one gallon tank, air/fuel mix follows. I have a second fuel line from the one gallon collection tank back to the air box on the carb so these vapors also get used as fuel.

[bill-mcnamara]

VinTin, good idea to bring those vapours back up to burn, otherwise they could collect in the bilge area, My application has a motor deck too, so air exchange may be limited.
Curious as to what volume of air/fuel mix we’re talking about???

[vintin]

quote Bill McNamara:

VinTin, good idea to bring those vapours back up to burn, otherwise they could collect in the bilge area, My application has a motor deck too, so air exchange may be limited.
Curious as to what volume of air/fuel mix we’re talking about???

I was running my motor one evening after dark in a tank and had pulled the return to the air box fuel line off of the one gallon tank. I noticed a stream of vapor about 10 inches long and a couple of inches wide in my flashlight beam. No doubt a highly combustible mix! This was as idle and surely more flow at higher rpm’s. It was a ah ha moment and it made me realize that we should be accounting for this vapor as it may present a possible hazard.

[Steve A W]

Vin in
Could You post some pictures of your system?
Thank You

Steve A W

Member of the MOB chapter.
I live in Northwest Indiana

[vintin]

quote Steve A W:

Vin in
Could You post some pictures of your system?
Thank You

Steve A W

I’ll try to get some over the weekend. The vapor return line attaches to a nylon barbed 90° elbow fitted snugly into a slightly enlarged fogging hole. Points straight into the carb. Fits behind the face plate nicely but is hard to photo without some dissasembly. EDIT: I found two photos but I’m using a 15 gallon Moeller tank these days. The 3 quart glass container is recovered fuel. I’ll get a photo of the air box set up and post it. The one gallon gas can with two hoses is the recovery tank. Yes, one is threaded right into the yellow vent opening.

[vintin]

Can we only post two photos per posting? I was having trouble adding these two photos to my other two above. Oh well here they are. Yes, it looks like two may be the limit.

To hold that nylon barb in place a short piece of fuel line is pushed onto the barb from inside the air box.

When I first started using this recovery system I would save the recovered fuel in 3 quart glass bottles so I could tell if any water were to settle out. None ever did so now I just pour the one gallon back into the larger tank leaving a few ounces in the bottom of the one gallon just in case. One time being the fool that I am I was running in a very heavy rain (Watching the Poker Run on Lake Lanier) and did see a small amount of water. It looked like mercury the size of a 50cent piece in a one quart jar that was half full of fuel from that days run. In cold weather I do notice more recovered fuel. Likewise more is collected when idling a lot. I have been out running in temps as low as 35°F and notice more collected. I suggest not going smaller than a one gallon tank for collecting as it’s not unusual to get almost a gallon collected per 15 gallon fuel used. Running hard of course collects a lot less as does running in warmer weather.

[Steve A W]

Thanks for the pic’s and explanation.

Steve A W

Member of the MOB chapter.
I live in Northwest Indiana

[chris-p]

I did a resto for someone that wanted the recovery system added.

It was a ’58 RD.

I installed a fuel pump, but kept the double line fitting and fuel line. The once AIR line, became the return line. Was hard to tell what I did unless you really looked.

As stated, you would be shocked at how much you recover, when idling, especially in colder weather.

[david-bartlett]

quote Chris_P:

As stated, you would be shocked at how much you recover, when idling, especially in colder weather.

This is the result of trolling with my RD in springtime cold water. Semi-synthetic TWC-3.

[Author]

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