Does anyone have any suggestions on how to break in a tower .46? The instructions tell you how to break it in step by step, but i didn't install the needle( tower 40 RTF), so I have no idea whether it is in leaner or richer. Very confused. Also, sometimes I have no pressure, and the fuel won't stay in the fuel line after priming. Thanks!

Also, when I have the engine running without the wings on the elevator and rudder vibrate significantly..

Balance your props first! Then put your plane together, turn the needle in (clockwise) until it seats (gently). Now back it out 3 turns and start your engine at a fast idle. Let it warm up for a minute then advance the throttle slowly to full. Please have your plane secured for safety reasons. Adjust your needle in or out to obtain peak rpm, the back out the needle slowly until you have a drop of about 1500rpm. The engine should then be run for about ten minutes then a 15 minute cool down time then repeat the above steps. Do this 4 to 6 times. When this is done, set your needles by adjusting the high end first, obtain peak rpm then richen it up until you have about a 200 to 400 rpm drop from peak (about 2 to 4 clicks). For the low end, at idle pinch and hold the fuel line. If the engine revs up 100 to 200 rpm then your good. Otherwise adjust the low end accordingly. Remember counterclockwise = richer, clockwise = leaner. The exception is for the low end on "Air Bleed" carbs which you don't have. Air bleed low end adjustments are opposite. This is an ABC engine, make sure you use a fuel that has some castor oil in it.

I don't know what you consider "seating." The instructions say to screw it in until you feel resistance. What is resistance considered when dealing with these needles??! haha How far should I scew it in? Can you simplify this some?

Resistance is futile! Sorry couldn't help myself! When turning the needle in, when it seats it will stop. Don't force it or you can damage the needle

Oh, so much simpler now . haha. thanks so much. However, lets say i seat it and then back it out 3 clicks. I now only have 3 clicks to lean. Am I making any sense?

You need 3 complete turns of the needle, place a mark on the needle so you have a point of refference. 3 "Clicks" will not allow enough fuel to run the engine.

I'm sorry.

1st -I seat the needle(turning the needle until i can no longer turn it)
2nd-make 3 complete rotations to richen?

Then I should work from there?

yes 2.5 to 3 turns (revolutions, not clicks)out, fire it up and run it for 2 or 3 minutes and let cool down completely... heat/cool is what accomplishes break in...do this several (3 or 4) times it should take about 2 tanks of fuel......some folks prefer to break in on flights for a few minutes at a time,engines do run cooler moving along at 30 mph but a bench breakin is fine.........balance prop as suggested, if parts vibrate excessively than they are either loose or engine/prop is out of balance

"Does anyone have any suggestions on how to break in a tower .46? The instructions tell you how to break it in step by step, but i didn't install the needle( tower 40 RTF),

how does it run at all without a needle?........Rog

Speaking of heat, it is a good idea to heat the engine with a hot air gun before you flip it over. this expands the cylinder before you try to start it. Not absoulutely necissary, but it reduces the stress on the piston and crome cylinder for those first few seconds. It is a procedure recomended by the best minds in the buisness. i don't even flip my prop untill the engine is hot.

Also a good idea to add some castor to your first gallon of fuel. I use Byron 10% nitro, 18% Castor/sinthetic blend and add about 4 ounces of castor. the sinthetics can break down with engine heat, but the castor does not.

Run it on the ground for a couple tanks, then fly it. be sure to keep the mix rich (you should see a exhaust mist when you are flying.

The OS engine comes with a manual which talks about break in. have you read it? if not do.

Break in is easy and somewhat forgiving if you don't do it exactly right. just be sure you don't run it lean, that's a killer, especially for a new engine.

Be sure you break in the engine as per the instructions with tower 46's I use them and ruined a piston and sleeve because I didn't follow the direction on break in.

ahhhh, now you have me worried ! haha

Don't be worried, as long as you run it on the "Rich" side you will be OK. A ruined piston/liner is caused by no castor oil in the fuel during breakin, running to lean or a defective engine. Take your time and run a good 4 to 6 tanks of fuel through it.