rsands2801

Hi,

I have had this engine running on the funtana and it NEVER gave me any issues. i installed it in the new plane and cant get it to run right. At full throttle it will go full thorttle then die a bit then pick up again then die then pick up - only works fine if i am 5 yes FIVE turns out. if i hold it vertical it just dies immediately no matter what settings i have it at. I removed the glow plug and it is BLACK and the top of the piston is BLACK!

I use this fuel

http://www.modeltechnics.com/glowfuel/propower.html

Pro power 10 - 18% synthetic oil no caster

any ideas?

bigedmustafa

My Feedback: (2)

If the engine was fine on a previous plane, and it hasn't sat for any long period of time, I'd be looking at plumbing/tank problems before I'd been moving the needles a whole bunch. An unsteady top end can be a tank pressure issue, and dying when going vertical is often caused by clunk problems. Both of these conditions will cause temporary overly lean running, which would account for black plug/piston top.

Pull the tank, make sure the clunk is hanging correctly, and try some fresh fuel line. Your engine trouble likely has nothing to do with your engine.

Good luck!

Jetdesign

My Feedback: (8)

Sounds like an air leak.

RCKen

My Feedback: (9)

As BigEd indicated, check the plumbing of your tank. Also, check to see if you have any "garbage" in your needle valve. The easiest way to check this is to remove the needle valve from the carb and connect your fuel pump to the fuel intake on the carb. Pump a bit of fuel into it, which should come out the needle valve housing. This will flush out anything that might have been caught in there.

Ken

rsands2801

i checked all the lines and they are fine - all new. clunk hangs freely but does seem to have quite a narrow opening - it came with the great planes plane. i haven't run the engine under 3 turns out and when i pinch the fuel line at full thorttle sitting on ground it doesn't pick up any RPM. no air bubbles coming through the fuel line either

rsands2801

sorry forgot to mention - took carb apart and made sure it was all clean - no dirt in there either []

Allfat

My Feedback: (1)

Keep leaning it out. My friends 55AX likes to run at about 1 and 1/4 turns out. I think you may be just really rich everywhere, especially if you have not even gone under 3 turns out. Try starting it at 2 turns out and then lean it out from there.

j.duncker

My Feedback: (2)

Checked the Clunk line??

Also check the O ring on the needle.

rsands2801

anything under 3 turns and when i give it throttle it dies - cant get it anywere near 2turns. clunk line is clean...no rips or cracks

rsands2801

would this fuel be making it run too hot? when its running i can touch it without burning myself.

CGRetired

My Feedback: (1)

What fuel is that? You are making a contradictory statement there. The fuel makes it run hot but you can touch it. Which one is it?

But, unless it's some wierd fuel, it most likely is not. Running it real lean will make it run hot, but it won't run hot for very long. Try to richen the mixture out a tad. You are not tuning for maximum RPM, but slightly less than maximum RPM.

Fuel serves three purposes: 1. Burns to produce power (but of course.. ). 2. Oil in the fuel lubricates. 3. Fuel also cools the engine from the inside. So, if you lean it out to much, it will not get the benefit of the cooling effect of the fuel plus it will not get the proper lubrication.

CGr.

rsands2801

sorry it does read wrong...i meant could the fuel be just "rubbish" lol - its the model technics propower 10% stuff. first time using it

i had the engine at 5 turns out and it still conks out when 90degrees vertical - at about 70degrees it runs fine - could a fowled glow plug cause things like this to go wrong at WOT?

rsands2801

if the mixture control valve is set too lean would this be whats causing me to have to go so far out in the needle valve turns to get it rich or running at WOT while sitting level?

ChuckW

A guy at our field had a .55-AX that was giving him all sorts of trouble similar to what you are describing. He asked me to take a look at it for him. What I found was a leak around the fuel tank stopper. It was hard to verify actually. Eventually though I discovered that the threaded back-plate for the stopper was stripped so the screw didn't hold properly. This didn't compress the stopper and seal it off as well as it should have been. Surprisingly, there was no fuel leaking out of the tank or there was very little. I guess it just leaked enough that there wasn't good muffler pressure in the tank.

I'd basically look at the scenario and decide what the variables are between when the engine ran good and now:
1- new plane and fuel tank/plumbing
2- new fuel
3- engine installed in a new plane and possibly something got into the system during that process.

evilhorse

last time i saw a black piston i bought an engine, the black soot is burned (overheated) castor. it may even have good compression, but it sounds like the engine is cooked, my Evo 40 did the same thing when she burned up, stalling out, wouldnt idle, wouldnt needle.
just my .02

Jetdesign

My Feedback: (8)

What is your low end set at? Did you change it when you cleaned the carb/engine? The low end adjustment affects the engine through most of it's operating range, although we notice it the most idle and during transition.

rsands2801

i just checked the mixture control and it is set at 2 out. i have reset the engine to guidelines of 1.5 out on mixture and 2.5 out on the main needle. I checked the piston were it is black and the bottom of the head and it hasn't actually caked the metal - it rubs off to a nice clean surface. i hope it hasn't burnt itself out!! just seems weird it has been running perfect in another plane but this plane it just isn't happening!

k3 valley flyer

My Feedback: (18)

Try using another tank strapped to the outside of the plane, you are not going to fly it this way, just to determine if the engine runs ok on a different tank. If it does you have tank problems.

VeeAte

Good advice from k3 valley flyer.

I have a tank set aside for exactly that. Comes in handy to eliminate everything to do with the onboard tank.

With your low speed needle (mixture) one way to make sure it is open the correct way is to wind it in and then while winding it out blow through a clean piece of hose into the inlet nipple. Just as you hear air escaping inside the carb as you wind the low speed needle out is about right to begin with.

rsands2801

i replaced the plug...back to my old fuel i have always been using and top end is much better. doesn't quit at 3 turns out and power range is fine. although if i hold it at half throttle temp is 105degrees C...if i open it up it reaches about 160degrees C - are these acceptable temps? exhaust has alot of oily residue coming from it though? i have a spare new tank sitting here...going to strap it on now and see were i get to

rsands2801

hmmm new tank and seems to be running colder...half throttle sits at 95 degrees c and top end about 145 degrees c - leave it open for a bit and goes to 155 - no air bubbles in line. 3 turns out and 1.5 turns out on the mixture needle. idles fine - leave it for a bit then give it full throttle picks up clean and goes straight to top revs. middle seems fine - need to test holding it vertical now. but does this sound about right?

im still getting a oily black substance from the pressure line though heading to the tank...bit lost on this one?too rich maybe? its a pitts muffler

Phlip

Black residue is not a sign of too rich, rather it's a sign of too lean. Although the problems you're having with the new set-up, new fuel and needing the needle way open probably did the damage as far as the accumulation of black carbon on the piston and head. That should clear itself out with a good tank set-up and several proper runs. Sounds like the problem, as most responders have suspected, has been with the tank set-up in the new plane. Get that fixed, tune up the engine and fly it! The black gook will go away.

bruce88123

You never said what kind of plane it's going into. Is the tank too low? This could cause a lean condition. What is the tank centerline relative to the carb spraybar? Above, below or same. Give distance in inches (preferred) or mm.

rsands2801

sorry its the great planes extra 300sp - tank centreline is with the carb centre line.

after i replaced the tank the black has got alot less - before if i put my hand beneath the exhaust and it would be covered - seems to be running alot cleaner now. now need to get the cowl put back on and test it vertical and lets hope it dont dead stick for the fourth time in a row...this plane doesn't like to glide to far

ChuckW

Black residue could also be a sign of a loose muffler. The aluminum parts vibrating against each other an create it. I generally use a little blue thread locker on the muffler bolts, tighten them down good then re-tighten them when the engine is warm.