Hi All. 25 years ago I quite often started and flew tee dee o49's. I recently started again but I'm having one ehck of a time starting the darn things. After they run out of fuel and you refuek, whats the secret to get them to start? I use a starter and it cranks and cranks. Any little tips or secrets you want to share?

You have got to start with an engine that is mechanically sound. If you can work the prop and find axial play [wobble], the case is worn out. The lower end needs to be free, but not sloppy. The cylinder should stay pumped up after you bring the piston to TDC for at least a few seconds. If it doesn't stay pumped, look for a head leak or bubbles in the exhaust ports. Bubbles in the ports indicates that your engine is only good for static display. Slop in the ball socket will make the engine run crappy, but it will run. If your engine passes these tests, then all you need to see is fuel spraying out the exhaust ports while cranking the engine...and just as importantly a good strong glow. It doesn't take much to get these engines to run as long as all the basic conditions are met. If you do a search on COX TD maintenance and tuning, I'll bet you come up with a few great articles.

2-volt battery, head prime, hit the prop, do not flip. Old mouse pitperson here.

All of the above, making a effort to visual check the glow in the glowhead. Better idea, put a fresh plug on. Also, clean the needle valve, venturi assembly as best as you can. ANY blockage can cause the trouble you are reporting.

If you have "spark', and the fuel flows right, it will fire.

Hi Again, I bought the motor on ebay and they said it was new never run and it did look that way. It runs strong, very strong when running, so I don't think it is being a wore out problem. Does it hurt to have the fuel tank slightly above the carb? It has a 2 oz tank (its round, about 1 1/8 diameter and about 2 inches long)and the bottom of the tank is about level with the carb. I think since the tank is above the carb, it will siphon out of the tank when holding the pickup tube level with the carb. Is it possible by the time I rehook the fuel line to the carb and get the glow wire on and starter spinning the prop, fuel has syphoned into the carb and flooded it (30 second delay). It doesn't seem like it is flooded though. I believe I've heard that a starter won't hurt a tee dee, maybe I don't have the meter turned up high enough and using a start it cools the glow head wire down enough where it won't fire. Another general question. I have a regular flight box with a power panel, when starting the needle on my panel (watts, amperage) reads between 2-3. At times I'd like to turn it higher when flooded, but I'm afraid I'll burn out the glow head. How high can I turn it up without damage to the glow head?

Fuel siphoning will cost you time as you already know. To clear a bad flood quickly, pull the head, pinch off the line and crank the engine over. Some guys use a soda straw and blow into the intake, this is even faster. You either need to get in the habit of parking the model with the nose up, or use a line clamp after fueling. I can't say what exact amperage figure works best for your glow plug, you want to use the least amount of current that will do the job.

Cox glow heads are in general very sturdy and you can crank up the volts/amps until they light up like a flashlight. The major problem people have in starting Cox engines is not having the glow plug hot enough. I use a two volt 5 amp/hr gell cell. In the mouseracing days it was mounted on the left wrist with two short leads going to a hot thumb. I have plugs that have 100's of flights on them, and a couple which died before I got the engine started the first time. So there is some variability, but most are sturdy.

A machined spinner will help start it. It helps act as a flywheel. Dubro makes a nice one.

Your tank is too big and too high. The top of the fuel level shoudl be even with the needle valve. It's also too large in my experience to ensure a consistent run. Something at 1 to 1.5 oz is as large as you should really go with. Or run it off a bladder tank so the pressure makes up for the larger fuel amount.

If it doesn't start then it's either dry or flooded. If you listen to the sound of the sizzle from the plug through an open exhaust port you can tell if it's too dry or too wet but close to starting. If it's a dry sounding sizzle then add some prime. If it's a wet sounding sizzle with crackles then it's too wet and you need to prevent any more fuel getting into it and burn off what is in there until it starts