New engine starting problems
 

Please could anyone advise on the below ?

Thanks


"hi,
i have just purchased a Jumper 25 by seagull with an SC32A engine.
once build was complete i have been only able to maintain the engine running for maximum 1 minute. mostly around 30 seconds. i am using 5% nitro as per instructions and have adjusted the needle up and down so many times but to no avail. i prime the engine each time and it starts and runs then cuts. when i check the fuel line it is empty? when i packed away through frustration and loss of light fuel poured out of the silencer. can anyone offer me any light on this problem as it is bugging me,
thanks"


"Just to add, because I was there too, and I'm not sure about glow engines, there is a tube to the nipple on the muffler and the filler tube is at the bottom of the engine bay with a bung in it. Assuming that the plumbing is correct (I didn't check the plumbing myself during the build as i couldn't see the poor diagram properly so I left it to the OP), what else could be causing the fuel to be hearing off back to the tank ? If the engine is running surely the pressure nipple should be forcing the fuel out of the tank anyway ! Maybe there are some simple checks to perform to be sure that the plumbing is correct without taking the tank out, which would not be easy ?"

RE: New engine starting problems
 

disconnect the line to the needle valve and blow into the line connected to the muffler presure with a full tank of fuel ,fuel should come out the line to the engine.if not try the other way around and see what happens.

RE: New engine starting problems
 

This can be a lot of things.

Find an experienced flyer and ask his assistance.
But aerowoof has cut to the chase with the first and best test.

You might not be filling the tank.
The pickup line may be sucking itself shut against the tank wall.
The pickup line may be sucking air. Hole in it?
The pickup line may actually be plugged to the fill overflow pipe in the tank that goes to the top inside of the tank.
You might not have the needle valve open enough and the engine leans out too much and dies.
Same with needle valve open too much. If the fuel delivery/pickup line is empty, probably not either of these last two.

The silencer being flooded suggests the fuel lines are incorrectly connected.
If it is the overflow line, pull it from the silencer when you fill the tank.

How many lines and what are they?

How long does it take to fill the tank? How big is it?

RE: New engine starting problems
 

Three lines into the tank. We used the filler line to fill it and then bunged it once complete. We used an electric pump and filled it until the fuel sprayed out of the removed carb feed pipe. Just typing this makes me feel that was the wrong thing to do as that carb feed pipe is on the clunk so its surely the FIRST pipe to see fuel and not the last ! If you have filler, pressure and clunk lines, what do u plug / unplug to fuel up. I didnt do i but I know that the owner bent one internal pipe up, one down and had a straight one for the clunk

Thanks

RE: New engine starting problems
 

it almost sounds like you have your pressure line and carb line mixed up;)

RE: New engine starting problems
 

Fill the tank using the line you have been using but disconnect the line going to the muffler and fill until you see fuel coming from it. You are filling the muffler with fuel the way you are doing it now. The fuel will take the path of least resistance and more will try to go through the muffler line than the carb.

RE: New engine starting problems
 

BINGO


Dead right. You got it.

The one going up inside the tank would usually be the overflow that signals a full tank. It's usually connected to the muffler to accept pressure, but not if the tank is setup as a uniflow. Doesn't sound like the owner wanted uniflow.
The clunk line is obviously the pickup line for delivery to the carb and with that third line wouldn't be used when fueling.

You sorted your own problem. Good on ya'.

RE: New engine starting problems
 

Line from the muffler should go to the tank pipe that points up inside the tank. You'd pull the line off the muffler when filling to watch for outflow that signals a full tank.

The line from the carb to the tank pipe that goes to the clunk can be used for filling, but with three lines, isn't usually used at all.

The third line is plugged except to fill. Unplugged and used to deliver fuel into the tank, right. Then plugged. It goes to the pipe that points down in the tank. Truth is, down or straight or anywhere doesn't much matter since it lives it's life with a cork in it.

RE: New engine starting problems
 

Sounds like you nailed it but check to make sure the clunk line in the tank is moving freely. a little shake when its empty or low and you'll hear it "clunking" around. IF YOU DON"T Hear it grab the landing gear with the motor towards you and sharply snap it back. this should free the clunk. :Dgood luck