Fuel Tank Problem
 

Hi,

I went out to fly my planes yesterday and had nothing but problems, one that I hope someone can hlp me with as I don't know what is wrong.

I have built a Black Horse Twister (Very nice to build by the way, everything went in nice and easy), but I have having a problem with the fuel tank. I doesn't look like it's suppling any fuel to the engine. I have checked the tank, no leaks, the tubes are correct and going to the carb and exhaust correctly. When you blown into the exhasut tube fuel comes out of teh carb tube.

This engine does have a tuned pipe and the tubing is very long to get to the nipple on the tuned pipe.

Can anyone suggest anything?

Thank you

RE: Fuel Tank Problem
 

If you blow in the vent and fuel comes out the feed, the engine should run.

Can you be a little more specific as to just what the problem is that you're having?

RE: Fuel Tank Problem
 

The problem is that the engine will not start. I suppect that fuel is not getting to the engine.

I have checked the glow plug, that the engine is turning.

I'm really stuck, can not think of what could be causing these problems.

RE: Fuel Tank Problem
 

Sounds like foreign material in the carburator, or a leaking filler valve. Pull the needle valve all the way out, leave the fuel line connected and blow through the vent line. Fuel should come out of the needle housing, but not through the filler valve. Then put the needle valve back in, but only a couple of turns, and do the same again to force fuel through the spray bar. Fuel should flow into the carburator throat. Turn the needle valve back in to the normal setting and take the glow plug out. Now spin the engine with the starter for 5 seconds to eject the excess fuel that ran into the carb while you were doing this. Put the plug back in and the engine will start.

Jim

RE: Fuel Tank Problem
 

Thanks Jim,

I will give that a try.

If that doesn't work shall I just replace the carb?

RE: Fuel Tank Problem
 

That a bit of a last resort.

What kind of engine?

RE: Fuel Tank Problem
 

It's a MVVS 40, very clean, it has done little work.

RE: Fuel Tank Problem
 

I would say to open the needle 2 or 3 turns, put your finger over the carb intake and crank it with an electric started and see if fuel draws up the line. If not, I would take the carb apart and give it a good cleaning.

RE: Fuel Tank Problem
 

just to cover all the bases you might check to see if the clunk is setting up aginst the rear wall(too long) i say this because fuel will still flow with pressure (from you blowing) but not suction. just an idea.

Gary

RE: Fuel Tank Problem
 

There is a very good chance that the lo speed needle is closed too far. Open it up a full turn and see if it gets fuel then. You'll have to retune but at least you'll know it's getting fuel.

RE: Fuel Tank Problem
 

I would try the following.

1) remove the glow plug, put your finger over the exhaust and use your starter to spin the engine. Does fuel go to the carb and is the carb wet or fuel blowing out the plug hole? If yes, you have enough fuel.

2) Test the glow plug to make sure that it does glow. If yes, then you have a good igniter and plug.

3) Spin the engine with your finger off the exhaust and the plug out to dry the excess fuel. Install the glow plug, Open the carb barrel 1/4 the way and spin the engine with the starter. If fuel does not go to the carb, put your finger back over the exhaust.

4) Doing the above, will start the engine. If it doesn't, it is either flooded or ??????

RE: Fuel Tank Problem
 

I agree with Gary's suggestion about checking the clunk tubing length. That happen to me.

Brian