gotcha ill try and tune it again. I was under the impression the plan should run forever at a nose down attitude

The reason we're being so persistant is that every one of us can:

nose our plane down, land, take off,

nose our plane down, land, take off,

nose our plane down, land, take off, and keep doing it all day long.

So we are as perplexed as you are as to why it is happening.

If we can do it and you can't, you MUST have a problem somewhere.

If there is nothing physically wrong, then there's only one answer to your problem - You're flying too long and running too low on fuel.

Feels like were all just pissing into the wind if you ask me.

-Steve

I beg to differ on both counts.

All it takes is a gentle glide at less than 1/4 tank ( somewhat similiar to what he is experiencing ) to cause this to occur as he describes.

You can do this for quite a while, especially when there is a headwind and you are coming down from high altitude....

Or worst still coming out of a blender type move into a gentle glide ( tore up a plane last weekend with just this move, when the engine died due to fuel starvation... ).

Adding a loop doesn't help much. It does delay the time before the "bubble" or air hits the carb, but when it does the motor can and will still cut out as I painfully experienced... yup I had a nice loop in the lines.

What does help is any measure that can be undertaken to keep the clunk in the fuel as long as possible especially when there is less than 1/3-1/4 of fuel in the tank.

If the fuel tubing can bend downward a bit w/o kinking, the problem is ameliorated to an extent ( or rather it's delayed until the tank is even more empty ). Even turning the tubing so the "natural" bend of the tubing faces downward helps this a bit too... that is unless the plane is inverted.

A header tank may help him to be able to run the engine until the main tank is almost completely empty... so that is not a bad suggestion, although it adds a bit of complexity and weight to his setup.

Or he can just time his runs to prohibit running the fuel so low... or do the same and install a bigger tank.

As MiniFlyer says "You're flying too long and running too low on fuel. "

MiniFlyer?

ROTFLMAO!

Ken, the loop seems to work. Thanks! and thanks to everyone elses advice too.

35 sec. is relatively long time in a nose down possition before the plane hits the deck.lol
i know it saids to make the intake line as short as possiable.

But on my nitro cars or trucks, those lines are almost a foot sometimes.

makesure there's not kinks in those brass tubing.
You might also consider installing those metal fittings with a larger ID.
Plus the filter you have on is contricting fuel flow.

ok have a question on a tank setup on how it works. Well i realize there is a line for pressure and one for feed fuel to the carb. i have a lancair and it has to vent lines on the tank one feed line and a gas plane that is the same way. except of course the gas plane doesnt use a pressure tap for the tank fuel is drawn from the tank buy the vaccum of the carb.

But anyway on the lancair what is the second vent line for wish i could draw it. i think i will try may not be very good but may give an idea if it is visiable. should i cap this third vent line or is it for fueling the tank. thae lancair is a cmpro lancair not greatplanes.

on the gas plane the issue is fuel running out of the vent line i have one plugged and the other of course open to the air on the bottom of the plane but fuel tend to spill out of it. most likely a normal occurance.

The third line is a fill line. They are normally used on planes that have a closed in cowl when you don't have access to the pickup line to fill the tank. The fill line here is usually connected to a fueling valve, a fuel dot, or some other remote fueling setup. It is curved to the bottom of the tank so that you can pump the fuel back out of the tank.

Ken

Thank you appriciate it thats all i was looking for great.

It should also be noted that on a glow engine, that line needs to be plugged when the engine is running

This is how I do all of my tanks.