The Raven

How run in is your engine? I've noted that the 46AX and 55AX often exhibit a flat spot in the midrange (side mounted and even upright). Fellow club members have also experienced the same.

With long term run-in, rather than the normal run in period, the midrange issue eventually fades away. In our club we now warn people not to mess with the low end mixture and instead just tolerate it until it fades away.

As for plugs, I only use OS but don't get overly fussed with which one I use. Same thing for tuning, once set for a particular fuel there is little reason to change it other than a massive weather change.

NM2K

My Feedback: (14)

This "not touching the needles" stuff is a mystery to me, IF that is what you were implying. If not, never mind. <G>

How do you know that someone else didn't handle the engine first and changed the setting?

Even Bax, from Tower Hobbies/Great Planes does not recommend assuming that the out of the box settings are correct.

I agree that tuning for best idle and transition right out of the box is rather pointless, but an adequate setting should be attainable. Those needles are there for a purpose - use them.


Ed Cregger

The Raven

I meant not touching the low speed needle, unless you're mounting the engine inverted there is little reason to touch it as most OS engines come with it set pretty close to ideal. Of course, tune the high speed (main) needle.

If the engine came out of the box it's unlikely to have been tweaked by anyone, the exception being those hobby shops that let people handle the engines prior to purchase.

Agreed, tuning for perfection out of the box is pointless. Tune it for running in and work on the final tune later on.

NM2K

My Feedback: (14)

I was referring to the low speed needle.

Every installation is different, requiring a different low speed needle setting too.


Ed Cregger

top242

Hi!, for stick 40 of great plans, what is the best propeller? Thanzs!

bigedmustafa

My Feedback: (2)

Try an 11x7 and/or a 12x6 if you have ground clearance for it.

CustomPC

I now have a 55AX which will go into my Global FreeStyle ARF whenever i can find the time to put it together.

There's a Sportsmans pattern comp at my club in a months time so that is some motivation to get the model flying asap.

top242

Thanzs! bigedmustafa

NM2K

My Feedback: (14)

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If the engine size is between .45 and .55, I would say try an 11x6 first, then adjust to bring the engine to where it sounds happy.


Ed Cregger

jeffk464

I'm running an apc 12x7 on my 55ax and it handles it no problem, however I'm only getting 10,000 peak rpm. I'm thinking an apc 12x6 might be the right prop for this engine.

kbailey45

My Feedback: (41)

The manual recommends a 12x7-8 or 13x6-7 prop. I am going to be running a 12x8 to start with on my Phoenix Extra 300S. Was wanting to sling a 13x6 but dont think I have enough ground clearance. Also want to try the 12x7

GrrlsFly!

I run it in my .60 size Hobbistar trainer. Really hauls. I run at less than 1/2 throttle most of the time.

Darn thing did dead stick on me all the time throughout the first tank of fuel. That was after a full, by-the-book break in and lots of tuning by very experienced pilots in my club. Last week, on a new gallon of the same cool power 15%, it suddenly stopped dead sticking. Haven't dead-sticked since. Still takes a couple tries to get it started the 1st flight of the day though... and I have to open the throttle slightly during starting a lot. But doesn't dead stick anymore.

There was a double clunk in the fuel line that I also removed, so that may have been causing problems also. Not sure. Could've been dirt in the engine.

[sm=confused.gif]

NM2K

My Feedback: (14)

I'm going to have to try the 12x7 and 12x8, just for hoots. I can't imagine a .55 pulling that size prop, then again, I guess I'm still seeing this engine as a .46 and not the well heat-sinked .55 that it is.

I just bought a Streamliner 3D model from AK-Models. Maybe that will be a good break-in/test bed plane for the .55AX.


Ed Cregger

ChuckW

I have a 12x6 on the .55 in my WM Rambler, it works great. I've also ran a 12x7 on it.

jeffk464

Just thought I would post about my 55ax and excelleron 50 again. This engine keeps getting better and better, it spins a 12x7 prop with authority, doesnt hesitate at all, seems to sip fuel, and is much less painful to my ears than any other 40 sized engine I have ever owned. Absolutely superb engine.

RoysterDW

Our Excelleron 50 is now running the new OD Alpha 81. Perfect match with unlimited vertical and same mount as the old 70 Surpass. We have guy at our club who has a 55AX in an Excelleron and yeah its a great combo as well

jeffk464

The 55AX is a very good match. I have pretty much unlimited vertical, but it really doesn't want to hang off the prop with my 12x7APC. I think maybe with a 12x6 it would have enough power to hang off the prop, but its so nice not to have the loud 2 stroke wine of most engines.

cfbhd785

Have an O.S. 55AX on H-9 Mustang PTS. Running a 12X6 prop, motor runs awesome. Plane is very fast and very fun. Hardly ever run it at less than full throttle. Been flying it for almost a year. Kind of hard to start with the weather in the 20's but other than that it's a great engine.

Gustof Wind

My 55AX is in a Katana GS profile and it's a match made in heaven!!!

RoysterDW

Just shoved my 55AX into a PA Bad Boy but still messing with props.

Was told a APC 13 x 4 Sport is the way to go for 3d?

NM2K

My Feedback: (14)

Everyone seems to think that that extra .03 CI over a .52 will put the .55AX into the monster .61 range of power. Don't forget the small crankcase that limits the size of the gas passages internally.

I love my two .55AX engines and am happy with them, but I don't see them as being significantly more powerful than my Webra .50 GT, Magnum .52, Rossi .53 or ASP .52 engines.


Ed Cregger

ARTP47

Have th 55 in a 4* 40 with a 13/6 need 15' for take of unlimited vert.

Yellowsierra02

I have the .55ax on my Pulse XT40 from Hanger 9. Its a sweat little motor. On a 10x9 prop it was turning 12,900 and then I put a Ultra thrust pipe on it. It will now turn the 10 x 9 to 14,400-14,600 with the Ultra thrust muffler. Im currently runnning a 10 x7 and it turning it 15,600. I like the 10 x 9 but it seemed to bog the motor alittle. I think the perfect speed prop would be a 10 x 8. As far as Speed goes it pushs my 60" Pulse to 105-109 mph. It done 133mph but that was in a Huge dive so I dont really count that.

Justin

TruBlu02

I use my 55AX on a SPAD 3D model. I have ran a bunch of props on it trying to find a good balace for 3D pullout power. I ran though a 13x4W, 12x6, 11x6. All worked good on this engine but not for this aircraft. Just not enough pullout. I ended up using a spare 11x4 MAS and WOW! This engine went ballistic with the 11x4 and it tach's around 15,800 on the tach. A little high but the vertical is incredible. I just got some 12x4's to try out. Great engine and a great all around erformer with a wide range of props.

Gustof Wind

Here's pics of my Katana GS with OS 55AX--13x6 prop--great vertical--smooth throughout the throttle range--starts easily--I generally use a starter but have on occasion started it by hand with no problems--first start of the day pull it through compression five or six time till you see fuel in the line and it'll start --a real joy to fly--as good as or better than the Italian Super Tigres in terms of starting and performance!