learjet45xp

Bob,

Just got a 60LX for my sundowner 50 and was wondering what prop you guys finally decided was the best match for this combo? Thanks

bob27s

My Feedback: (19)

Actually a 9x7 has been fastest so far. Mike had an old Zinger 9x7 wood prop that really moved too.

Keep the engine rpm up.... that is the important thing with this engine.

Bob

learjet45xp

OK. I will try out that size prop to start with then. Also, I am running the Jett bubbless tank system. I was wondering, it seems like the carb shuts off prettty tight when fully closed. Here is the fuel system I was thinking of running. Let me know if you think there is a problem with it. I would like to run the fuel line from the tank, to a "T" and then from there to a one-way check valve and into the high speed and then the carb. Obviously a fuel line would go from the "T" to a fuel dot as well. I figure I would evacuate the system through the "T"and it wouldn't suck air from the carb because of the one way check valve. The only air left in the system would be from the check valve forward, nothing in the tank. Then when fueling, the fuel would push all the way to the carb (which would be fully closed) and also completely fill the tank. Any problems with this setup? The only thing I could think of is that the whole fuel system would be under pressure and when I went to open the carb it would flood it slightly, but then again I suppose I could pull the stop on the dot out afterwards and slowly relieve the pressure there.

bob27s

My Feedback: (19)

worst thing you can do to the fuel system is make it complicated.

You will still flood the engine with what you described.

Take a look at the Edge photo I have on the Jett website ....... BSE-40 - 76L page ........ just run a line out and back into the cowl with a joiner in it.

Bob

learjet45xp

How do you keep the air from getting into the tank without a check valve though? I guess if you fuel it right there isn't any real room left in the tank for air anyways?

bob27s

My Feedback: (19)

Only two fuel tubes are involved - feed and vent. No need for a check valve of any kind.

Feed line from the tank meets at the joiner and then continues to the engine.

The best way to fuel the bubble-jett tank is by using the jett tanker.

Proceedure is to disconnect the feed line coming from the tank (either at the engine or at a joiner as I have shown), connect the tanker, and use the tanker to remove as much air from the tank as possible (suck the air out). This just gets things started a bit.

(note, if you are fueling with a smaller syring or other device, yes..... at this point you want to clamp off the feed line with a clip or hemostat to prevent air from entering the tank again)

Then fill the tanker about 3/4 of the way full of fuel.

Reconnect to the feed line, then hold the tanker upright, and draw out on the plunger to ensure all of the air is out of the tank (will suck out bubbles and then meet resistance). Any air will rise to the top of the fuel inside of the tanker. Result is you extract air then add fuel in one operation.

Keep the tanker upright and slowly push down on the plunger to fill the tank. When resistance is felt, stop, and slightly pull out on the plunger. The tank is full. Usually at this point I clip a hemostat on the feed line to keep it from spraying fuel at me when I reconnect the joiner. And I ususually leave the hemostat on until I am ready to start the engine.

The tank bladder does not pressurise the system... does not stretch ... but sometimes after fueling it does hold a little pressure to let fuel squirt back at you. So use a little caution.

The operation of the bubble tank is dependant on getting all of the air out first. A syringe or the jett tanker does a good job of this.