engine trouble

i have a tower hobbies .46 runs great when sitting still, but when i point plane straight up, engine suddenly dies. is this an adjustment problem?

Reply to
mike
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Yep, sounds like it is too lean. Turn out the needle valve 1/4 to 1/2 and try again.

Reply to
James Beck

I have a Towerhobbies .46 Runs great when sitting still and level, but when you aim plane at sky, engine just dies. Any ideas?

Reply to
mike

Your high end needle is TOO LEAN. GMA taught me to tune my engines with the tank 1/2 full and set the peak RPM with the engine pointing up to avoid lean runs.

Good luck

Reply to
Six_O'Clock_High

What he said!

Reply to
JosLvng

Others have already told you the problem, it's too lean. Some other things, just in case. First, you did install the muffler, right? Second, you did run a line from the muffler pressure fitting to your fuel tank, right? And finally, before you installed your fuel tank you did a pressure test to make sure it's sealed, right?

Reply to
C G

It's funny how sometimes the obvious must be stated or it just seems to not get done. :) One other thing to check, have you had a sudden stop type landing? Check the tubing between the tank neck and the klunk. If you have had one of these, the tubing may be kinked and could cause your settings to go lean.

Jim W

Reply to
Black Cloud

Since it sounded like he was new to this, I thought it would be helpful to mention them.

Reply to
C G

Yes. It is too lean.

Reply to
Paul McIntosh

Reply to
jim breeyear

Maybe. Pointing the plane straight up isn't some sort of "Universal Pilot's Salute" or gesture of respect/sacrifice to some god.

Run the plane to full throttle and point the nose straight up. The plane MUST be running full throttle for the test to work. If the plane up and dies, it's way too lean. If the engine sags a little, it's a little lean. If the engine speeds up signifigantly, it's too rich.

Ideally, you want the engine RPMs to increase SLIGHTLY when you point the nose straight up. This shows you're slightly rich.

Reply to
Mathew Kirsch

DARN IT! And all these years I have been working so hard to perfect the procedure.

Actually I point the nose up and then go to full throttle and adjust the needle for max RPM and then richen it up ONE click. That way it gets rich enough when I put it down level and it is tuned as good as I want it.

Reply to
Six_O'Clock_High

It's possible, but there is another possible cause

Has the clunk been thrown forwards in a possibly harder landing than normal e.g. one where the model was stopped by running into some obstacle. If this happens, the feed can be at the front of the tank instead of the back and in this case a nose up attitude will starve the engine of fuel.

HTH

Malcolm

Reply to
Malcolm Fisher

Reply to
Donduk

I tried to respond to this some time ago, but it seems to have gone astray.

There are a couple of other possibilities -

Clunk thrown forwards in a sudden stop - runs OK when level but starves engine of fuel when climbing vertically or even quite steeply.

Pick up tube fractionally too long. Again ok in normal flight, even inverted, but when vertical pick up touches rear wall of tank and again starves engine of fuel.

HTH

Malcolm

Reply to
Malcolm Fisher

Been there, done that in both cases. It is amazing how little of an abrupt stop can cause the clunk to flip forward. I had one not only flip forward but loop itself over the vent tube. One more proper shock and I bet it would have tied itself into a loose knot. Usually you can bang em back into place. I had to dismantle the tank to fix that one.

Reply to
Fubar of The HillPeople

Reply to
<strathboy89

Now THAT is a good idea.

Reply to
Six_O'Clock_High

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