Newmanator

Hi,

Recently I converted my Wattage MadDog to glow power.

I went out and bought a AP .15 yellowjacket, 4.oz tank. engine mount, tubing, broke the motor in running it at full-throttle and very rich (per manufacturer's instructions) about 2 fuels tanks worth. I Noticed that if I hold the plane in a vertical state, the motor starves and dies unless I adjust the needle. I have 2 flights on the motor now and each of them have resulted in the motor running poorly after about 3 minutes in to the flight.

What I have been doing is starting the engine, holding the nose vertical at full throttle and adjusting the hi-end needle valve to highest rpm. Once in the air, the motor seems to run pretty good, 3 minutes in to doing loops, going vert, and basic maneuvers its starts to sputter and eventually quits, which makes landings interesting [:@]. I have heard that these engine take a long time to wear in, is this all that I may be experiencing?

Can anyone please give me some advise, or similar experiences/fixes?

Thanks in advance,

Mike

dieFluggeister

It sounds as though you may be running the engine too lean and it is getting too hot and quitting.

I have not run the AP but just a few rules of thumb for most engines.

Mount the middle of the tank should level with the carb. Mounted too high or too low may cause it to run too lean or too rich.

Tune the motor with the plane level and at full throttle. Once started, turn the mixture screw "in" (lean) until the highest RPM is attained or you hear it start to sag. Then immediately back it out (counterclockwise) until you hear the RPMs drop.

Tilt the plane up at least 45 degrees and listen to the engine. If RPMs change it is still too lean. Keep backing the screw out until the RPMs do not change when the plane is tilted.

This setting should be real close for the optimum high speed adjustment.

Just remember that an engine has a life span of a minute or two if run too lean. It will speed up then "sag" and finally it will get hot and seize.

It is hard to ruin an engine by running too rich though, so always stay on the rich side to be safe. Running too rich the engine will sound "burbly" and may slow down and quit or even quit suddenly. You can then be safe to lean it out a little.

SST

My Feedback: (2)

I have one and it's a POS! I ran nearly a quart of fuel through it on the bench before trying it in a Ripmax Alienator. My Norvel .074s develop more power than this pig.

jessiej

[I ran nearly a quart of fuel through it on the bench before trying it in a Ripmax Alienator]

That is not much running for any engine that needs a bit of break-in. One of my (2) norvel .074s took a good bit more, some require less. DieFLUGGEISTER HAD SOME GOOD ADVICE.

jess

Newmanator

Dude, lol... thanks for the words of encouragment!

Mine has loads of power, my MadDog gets small really Quick... I have a feeling it gets too rich, after 3 minutes of flying, otherwise I think it would sieze as dieFluggeister pointed out

Andrew

Are you running pressure? If not, try it -- it may help your consistancy.

When you are needling the engine when vertical, pinch the fuel line for a second. If the engine speeds up, it is still rich. If it slows down, then it is too lean. Pinching the line effectively leans the engine temporarily and can give you an idea of where to go with your mixture. I have no AP experience, but it sounds like you are going lean in the air.

Lastly, like dieFluggeister said, it may not want to hold setting until you get some more run time on it. Two 4 ounce tanks on a .15 isn't much.

Newmanator

Hey!

I want to thank you all again as I am new to the 2 stoke realm. On my way home from work I went flying again and made the adjusts you all mentioned and my plane flew awesome! I am really a proud owner of a converted E-plane and that is a huge sense of gratification.

Thanks to all for there input!

Mike

jessiej

Great!

jess

rpmtech

My Feedback: (6)

Yes too lean. These seem to run best rich. There should be alot of smoke when flying, and yes they do take a bit to break in. But the one I had was great!

John C

You didn't indicate what prop and fuel you are using. With an 8X4 Master Airscrew prop and 25% nitro I got only 12,000 RPM at sea level. I took the muffler extension off - it unscrews - and gained 700 RPM

It's a bit noisier, but not excessive in my mind.

John C

Newmanator

When I broke in the motor and the first 4 flights I used a 7X4 running 15%. My last flight I used 35% and a 8x4. It seems to pull really well with the new setup. The manual for the yellow jacket says it will turn 18K?

Mike

John C

I can't check my documentation, but the 18K is where they obtain maximum HP with some toothpick prop and unknown fuel. I doubt you'll see anywhere near there although some guys I have talked to say a tuned pipe works wonders [:@]

John C

Newmanator

Can you buy a tuned pipe for these lil bugers? Or do you have to customize? I made an extension out of some aluminum tubing that Directed passing fuel/oil down below cowl. If you know a source for a pipe, please let me in on it!

Mike

Sharang

Can anyone please tell me where I can find the instruction manual for the AP .15? Thany you.

Sha

Falco250

This thread might be of interest:

http://www.rcuniverse.com/forum/m_75...tm.htm#7543691

aspeed

My .15 didn't come with instructions, but the .09 did. In response to the previous message from 2005? I just made a header myself. I had to buy a die that cost almost as much as the motor. The original exhaust lost 2400 rpm with the muffler compared to no exhaust. The .09 was only 900 rpm. I made a new stinger for the exhaust so I could get a hole around 6mm. Just unscrewing the stinger is ok though. I kind of like mine, but think a new rod is in the near future because I ran a little F2D prop on it for a while at 25,000 rpm with a contol line carb. I'll stick to a 7-5.

Sharang

Hi aspeed,

Would you be able to scan the instructions for your .09? I cant seem to find them anywhere online for these engines. Also, since you have this engine, could you please tell me what you think about it? What application did you use it for? How did it idle and transition? Thanks in advance for all your help!

Sha

skaliwag

My Feedback: (1)

AP 15 scans

aspeed

The .09 is just sitting, it runs good for an .09, throttles up nice on the test stand. The .15 (which is really only a .137) was about 3,000 rpm more than the .09, but like I said really picked up without the muffler, and opening the venturi helped too. I was going to put it on a control line combat plane, but will likely use the OS LA .15 now because I already drilled the holes. I modified the carb with an airbleed hole because it it didn't idle very slow and opened up the bore, but I think I screwed it up. The stock one is ok now that it is broken in better. The AP .15 with muffler stock was 13,300 rpm on a 7-5.which is dismal. 15,700 and 4500 idle without muffler, and 17,600 with a bigger control line carb. It is really just a bored out .09 and doesn't quite make a .15, but is very light, cheap and performs well compared to anything else in that price range. ($30 is cheaper than a Cox) It breathes like an .09 so the muffler is the weak point.It shares the casting, crank etc. but not the piston/cyl. and head. It is good for flying around stuff like trainers, maybe a Sig Wonder is in the future for mine next year or something. Skaliwag, thanx for the scan I was worried I couldn't load it onto my computer.

Sharang

Skaliwag, thank you very much for the scans. Im getting this engine new but without the box and instructions and I just wanted to make sure I do everything that the manufacturer suggests. Thanks again.

aspeed, Thanks for the review, Im planing on using it on one of EAC's baby pattern kits. Im not much for raw power but value reliability much more. Thanks again.

aspeed

Just clearing some emails and remembered this. I got a pic. It is on the bottom of the pic with the black finned head if I can load it. Someone was asking (seven years ago) about a pipe. It is an Ucktam pipe.

Bob Paris

My Feedback: (13)

Hi,
I have run four of these little .15's and the reason I used them, was because they are light...but not to powerful. I turned a twin star into a four engine model, buying two more naceles from Tower, fuel tanks and nacel covers. One was a turkey...and never did run well. Two were ok an ran well, and one was a real power house. Go figure...all four engines came out of the same production run too. You can buy spacers for the muffler, so you can stick that exit tube in just about any placement you want.

A Fox .15 will out pull two of these engines...easily, and to be honest...not the best choice for an engine in this power range. OS, K&B and Fox have better running .15's...with Fox the most powerful.

Soft Landings Always,
Bobby of Maui

aspeed

I opened up the exhaust on mine and it helped a lot.  Just unscrew the stinger  and it is a 5mm hole.  I made a new stinger with about a 6mm hole and it is much better.  My Fox BB wasn't much better than the AP (it is really only a .137).  I put an old Rossi .15 head on with a turbo plug on the Fox and now it goes pretty good. My LA's are better than the Fox though before the Turbo head, especially without the muffler.