I have a SPA3D with GMS .47 running a 10x6 MAS and it loses power then deadsticks when it goes verticle. This is very bad because I am trying to learn 3D, so when it deadsticks it flies like a rock, no glide slope at all. If it wasn't a SPAD it probably would be all over the runway by now. But when I hold it verticle it does the same and then starts smoking, not just the muffler but the whole engine!! I am guessing that this is bad but am not sure. I have tried it from quite lean to quite rich and nothing helps.
Karter

This is VERY bad. You're running the engine EXTREMELY lean. Much more of this and you can kiss that engine good bye.

With the plane level and the engine at full throttle, briefly pinch the fuel supply line. If the engine sags instantly and dies, it's too lean. If it runs for a while, then dies, it's too rich. It it increases speed briefly, then starts to die, it's about right.

Don't try to fly 3D until the engine is properly broken in and tuned correctly.

Please get with a local pilot who knows how to tune engines and let him show you what to do.

Dr.1

go-kartowner,
What DR1Driver said is solid gold advice. You're running your motor way too lean, you need to richen up the mixture or you're more than likely going to ruin your engine.

Ken

Well the thing is that I ran it really, really rich, until it was four stroking then toned it slowly down until it was really lean; it still quit. Ill try the fuel line thing though, as soon as I find a new carb hold down nut[:@] It fell off on a dead stick at the field and i cant run it now. I noticed this when I was running it at my house and the carb was shaking everywhere, luckily I had sealed it with silicone so it didnt fly off.
Karter

If the carb was "shaking everywhere", it was probably sucking in air too causing a lean run. Get the engine put back together properly before even starting it again.

Also you may want to check out the tank and be sure that everything is right inside ( clunk working right ) and that there are NO air leaks in any of the fuel lines or connections. ENJOY !!! RED

Red head is right. If the clunk got stuck at the front of the tank during one of your "landings" it will be out of the fuel every time the nose goes high. Hold the plane nose-up while running at hi throttle and see what it does.

In addition to probably being too lean, your prop is too small for that engine & it is likely hitting 16,000 RPM plus. The combo of very high revs & perhaps a very lean mixture will quickly kill the engine as dead as a rock. I hope that you are using fuel with some castor oil in it!!

A 10-6 is really a break-in prop for that engine & it is also wrong for a 3D application. You need a large diameter, relatively flat pitch prop that will let it turn ~12,000 - 14,000 RPM range. A 12-4 would be a good choice, as would a 12.25-3.75 for a 3D application using that motor.

I am using 15% fuel so it has some oil in it. I have a 12-4 that I will try on it. The so-called "landing" i only had one of, but I will check the clunk anyway.
Karter

I'm specifically referring to a castor-synthetic oil blend, rather than straight synthetic oil in the fuel's lube package. What brand is the fuel?

The fuel isCoolpower.
Karter

That is all-synthetic. It is OK if you never run lean --- but [] --- undersized prop & cool power -- ouch [:@]

Maybe the engine is OK -- but you have probably been mistreating it.

Since your supplier sells Morgan fuels, I suggest that you use Omega (the pink stuff). It has castor oil in it & can protect your engine to some extent from lean running. You can still use the Cruel Power, but make sure that it is running safely rich.

Ill finish up this jug of Cruel Power and then switch to Omega. Wait...doesnt Coolpower make Omega?? Could I use 40% Omega fuel? Would this hurt anything or would it help? [link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGHC4&P=0[/link]
Karter

I 2nd what dr.1 driver says. If you pinch the line going to the carb and imediately release it, the engine should increase in speed briefly and then settle back down. If it dies when you do this you are too lean.

The percentage listed is nitro content. I think that CoolPower has 18% synthetic oil and Omega has 18% oil with castor added.

40% nitro is WAYYYYY more nitro than you want and did you notice the price? Do you want to spend $90 per gallon????

Get 10-15% nitro in the Omega and you should be fine (along with re-propping it).

No, Morgan's makes both Cool Power and Omega. 40%??? You like buying connecting rods, don't you?

Stop abusing that engine. Run standard 15% Omega and don't lean it out to screaming.

Dr.1

Bruce you have got to get your eyes checked. The fuel is $92 for 4 gallons not 1. This adds up to $23 a gallon. That is still alot but not even close to 90 bucks a gallon.
Karter

Still way to much nitro for your engine.

You must have missed the fine print, $67 per gallon shipping!

I'm not sure if this applies to 2-stokes or not, but according to Saito's manuel Fuels composed entirely of castor oil is NOT reccomended but a blend of Synthetic & Castor oil is acceptable an can be found in Cool power, Omega, H9 Aero-Blend, K&B, & Power Master.

Cool Power contains no castor oil.

If your clunk is not in the front of your tank, take the stopper out of the tank anyway. I fought this same gremlin several years ago. Turned out to be that the fuel tube between the clunk and the stopper had a tiny cut. Probably did it when I installed the pickup tube in the tank. Brass tube can be really sharp. It nearly drove me nuts trying to find the problem. Once I realized what was wrong, the fix was immediate (well, almost, since I had changed all the carb settings, and had to reset the low and high needles).