mt_100

No sure if .15 is classified as 1/2a but seems this is where the small engine knowledge is.

I bought a Magnum XL15A used and when I got it both needles were closed. I adjusted per the manual to get it running and then adjusted as needed to get it running right.

Idles perfectly, and transitions from idle to full really well. However with a 7x6 prop I only get 10,200 RPM so the plane feels weak.

I am new to glow engines but an experienced guy at the field took a look and said it seemed to be adjusted fine. Fuel is Cool Power 15%. I also tried a different fuel with castor in it, no luck.

Currently it puts out more residue from the exhaust on a 3oz tank than my OS55ax does on an 8oz tank so it seems very rich. However any attempt to lean it out just causes it to stall even after a few clicks of the needle.

Any ideas on things to look for or is it possible that the engine is just worn out?

One last question. How would an ASP .12 compare to the Magnum? Right now I have to fly full throttle because of the lack of engine power.

airraptor

My Feedback: (66)

you should get more than that like 15,000 or so.
Fresh fuel, correct glow plug, is it broken in?

mt_100

Brand new fuel and glow plug and since I bought it used it should be well broken in by now.

DeviousDave

Too bad you aren't on this side of the state, I'd take a look at it. If you are ever in the Detroit area, give me a shout and I'll see what I can figure out.

airraptor

My Feedback: (66)

did you ever take it apart? maybe the sleeve isnt installed correctly.

mt_100

Personally, no, I have never taken it apart.

nh4clo4

My Feedback: (33)

Check the sleeve, My 25 dropped rpm, and the sleeve was just off enough to not flow properly. and since it is used, it probably has been apart. Make sure the exhaust opens first when the piston goes down, and the port is centered at the exhaust.

Lnewqban

Does your engine have an insert in the carb's intake?

Copied from http://www.hobbypeople.net/index.php...c-engine.html:

"Updated!!!Many competition events using 15-size engines have maximum rpm limitations. The Magnum XLS 15 exceeds these rpm limits in many conditions. This updated version of the powerful Magnum XLS 15 uses venturi inserts to change the carburetor intake size and limit the RPMs of the engine. The engine comes with the standard insert and optional inserts are available separately (a set of 4). Item No. 280027 (see hopups listing)."

Also, the manual recommends using a long-reach, hot heat-range glow plug.

earlwb

I would suspect that the cylinder sleeve has rotated off center and it has all the ports partially restricted. When you look in through the exhaust on the engine, you can see the cylinder and its exhaust port. If it looks odd or like it is half blocked, that is likely your problem.

mtntopgeo

My Feedback: (12)

For a stock XL .15, ditch the 7x6. Way too much! On my XLS .15s, I use a thin skinny 8x4. Gets just shy of 17K. For a generic"go-fast" prop, use a 7x5. Still it's a good idea to look into the exhaust port & see if the port alignment is ok. ................. George K.

mt_100

Dumb question, sorry. This sounds like something I could take the muffler off and see through the opening right?


Not sure, doesn't look like it but I am going to take the muffler and carb off and look into some of these suggestions. I am new to glow and the other engine I have runs so great that I don't have to worry about it.

Is there a good way to make sure there isn't anything in the fuel inlet, like compressed air?

Lnewqban

Try to get help for any modeler that has experience with glow 2-stroke engines.
These problems are easy to solve, but the proper diagnostic requires some experience.

This is good reading for you:

http://masportaviator.com/category/advanced/engines/

http://masportaviator.com/2004/06/03...one-tells-you/

airraptor

My Feedback: (66)

take a pic of the exhaust port with good light so can see the sleeve

mt_100

OK, engine is off the plane and muffler is off. Prt looks lined up straight and no blockage.

Don't see any inserts on the carb to restrict it either.

Still baffled on this one but looking.

One odd item. The engine seems to have a fuel on it. My other glow engines don't have fuel on them (sides and back). Wondering if there is a leak somewhere.

May just bin this one and get a new one.

skaliwag

My Feedback: (1)

"Bin" It my way.....

Andrew

The liner on that engine is pinned - unless the pin has been lost, it should aligned correctly.

aspeed

I'd check the headspace. It should be around .010" to .015"  It likely has a head gasket in that isn't needed.  It sounds like it is under compressed to me.  Low compression from either wear or too much head space.  Another thing I always do after a motor is sitting for a while is put my finger over the hole in the carb while it is running a few times  until it almost stops.  This sucks any old caster or dirt through the needle and passages.  Works on cars with carbs, 2 stroke motors and lawnmowers too.  Otherwise make sure the throttle is wide open which I'm sure you know and make sure the liner isn't in backwards.  Exhaust port hole should be higher than the bypasses as all the other people have been saying.  If it is pinned this likely isn't possible, but a previous owner may have pulled out the liner and bent the pin, raising the liner or who knows what.  I have seen some pretty strange things in swap meet motors.

mt_100

Looked at everything and just don't see it. Probably some lack of experience with glow engines involved.

Does anyone know of a glow engine repair service I could send it to that is reasonable?

aspeed

Before you send money for postage.... take the head off and take the shim out of the head and reassemble with a bit of thick oil or grease on the area where the head gasket was, tightening the bolts in a criss cross pattern in a couple of steps.  Also check to see how long it holds it's compression.  It should be at least 5 seconds. See where it is leaking if it is.  Little bubbles going out of the exhaust, or from the head gasket area.  I tried my new one with no muffler (because it wouldn't fit on the test stand)  and it goes 16,900 RPM with a 7" 6" Master Airscrew prop.  I would only suspect a drop of 1500 rpm with the muffler.  I haven't flown mine yet but it is a strong motor for the money.  The AP .12 or .15 is slightly slower if you were thinking it was an upgrade.  I still like my AP .15 with no muffler for cheap thrills though.  Hobbypartz has any of them pretty cheap with free postage if you are 'lucky ' enough to live in the US, and they are in stock. I also wouldn't recommend an OS plug until you get it running right.  They are a bit shorter than a 'real' long plug. and could be slowing you down. I can't see it being that much though.

mt_100

Can anyone tell me what your needle settings are? Just want to compare.

vertical grimmace

My Feedback: (1)

Agree on the prop here. 7-5 for speed, 8-4 for combat or more pulling power.

You say the engine has fuel on it? Is it brown and discolored? Like baked on? If so, this is a sure sign of some lean running. That, plus you are down on power, you may have an engine that is toast. You may need to replace the piston and sleeve. The price you pay when buying used.

mt_100

Not baked on, like it is leaking fresh fuel from somewhere.

Thinking because it runs OK, it is indeed toast. Gotta love sellers of used stuff. A new piston and sleeve is $19.99 + shipping so almost the price of another engine.

The plane it is on is for a .10 - .15 so I thought I would either get an ASP .12 for it or get rid of the whole plane and be done with it.

vertical grimmace

My Feedback: (1)

Well, I would prop it according to the power it has available. Run a 7-5 on it. If your engine looks clean, it is probably in good condition.