Yet another newbish question. I can't get my engine started lately, and I am wondering if the glow plug starter is the problem. When I hook it up to a plug, I get a bright orange color on the plug. Is that hot enough or do I need more?

A bright orange should be enough to cook off any kind of flooding problem of the plug. You should hear it sizzle a little when trying to start, if not your still not getting fuel though the motor. Flipping the motor over too slowly will also cause a no-start condition. You will have to look at another area of non-starting other than the plug not being lit well enough....

Well I'm flipping it with a stick the same as when it started before. All I've done though is the rich break in then I tuned it just shy of peak on the high speed last time I ran it.
I get a little grunt on about 1/2 my flips, so it's trying. I've also primed it well so I know there is at least some fuel in the engine.
It's a ST 51 by the way.

Any help?

Yes it is a help. Sometimes you have to start with the needle on the rich side of things....plus watch your throttle opening. I usually go with about 3/4 throttle. If its just after break-in, you will experience a little bit of hard starting still I would think, but that doesnt really explain why you had better luck before, huh?

Well I was running sloppy rich before. As far as I know, that's the only thing that has changed though.

Well if it starts on a prime, revs up high and dies, your too lean. I suspect your needle is too far out for it to clear out and keep running. You can disconnect the fuel line and flip it without moving the needle, and if it finally starts up and goes, it will confirm you were too rich with the needle.

Depending on fuel grade, fuel delivery to combustion chamber and a few other subtleties, I have noticed on various occasions that a plug that looks good when lit out of the engine may still not have the right heat once installed back in the engine. Could be you're getting enough heat to make it fart, but just a bit short of enough heat to make it catch and run. Could be the grade of plug itself is not what your engine/fuel want.

I have a Hobbico starter box with a glow driver that permits adjustment of glow heat over a considerable range, and have found some plugs/fuel mixes like to be at the top of the range to start easily, while others at the top of the range pre-ignite, backfire or start backwards, and want a lower heat to start easily. Some plugs are rated for 1.2 volts, some for 1.5, maybe others in between.

Lots of stuff has been written about selection of glow plug, and sometimes even the engine manufacturer's manual gives a plug recommendation that is not optimal in practice. Again, the grade of fuel you're using has an influence as well.

If you're getting farts but no starts, the first thing I'd try is either a bit more voltage to the plug if you have a means of adjusting that, or a freshly charged igniter, or substitute a hotter plug. For easy starts you need the right combination of plug type, fuel/air mix, grade of fuel, voltage delivered to the plug, and maybe another factor or two that escapes my notice. When you get the right combination, note on your engine box or some other permanent record what the components are for easy starting and clean running.

If it's a popular engine, other guys at the field can maybe tell you what combination works for them. I wish I could make it simpler for you, but unless you can get a good working combination from someone with the same engine, you just have to experiment.

The fact of it being a new engine should not matter much. I've had plenty of brand new engines start easily on the first flip.

Also, an electric starter will often help give a good fuel/air mix, at least eliminating that possible problem. I presume you are priming a cold engine? I normally start an unfamiliar engine at about 1/4 throttle opening, but sometimes find I need to go to half throttle to get an easy start. Once I get the thing figured out, it should start easily at idle or just a couple clicks above idle.

We need to hear from someone who has an easy starting ST51 what plug and what fuel they're using. Supertigers in my experience are not hard to start. I had an ST90 some years back that liked a hot plug (K&B 1L). One pretty good glow flyer at our field puts 1L's on all his engines. Others swear by OS 'F'.

Oh oh well mine starts with one flick but I guarantee no one else will do what I do. Fuel is 25% all castor and no nitro, plug is some kind of idle bar that glows when I hook up the battery, engine is inverted and throttle is non existent so it's flat out (ok, flat out 4 stroking) all the time. Did I mention it always starts with one flick? Oh, I do at least give it the prime it needs .

See? This is why you have to be careful what you ask for!

Fortunately downunder is well known for his many outside-the-envelope investigations, as well as valuable contributions to these forums, so we will overlook the oddness of this particular combination. Is this another of your crazy experiments, downunder? What do you do when all that castor turns to varnish?

If you use a good grade of castor and tune your engine correctly the only "varnish" you will see is a little brownish baked on castor on the head and silencer. And that depends on how well the mating face of your silencer and exhaust stack seal.

Varnish in the engine using castor oil as the lubricant is a product of:

1. Running too lean and overheating

2. Using a poor grade of castor to begin with

I use castor as 50% of the lube package (special degummed 1st pressing) and have never seen varnish inside an engine of mine.

No synthetic has the film strength of castor. But let's not start another oil thread, please!

You must excuse me for yanking your chain. I threw in the varnish question only because I bought a used engine that arrived practically frozen with castor varnish. I complained on principle, but solved the problem with an alcohol soak. Engine is doing fine now (big Moki).

LOL you just had to mention it didn't you.................I always wondered why they put the tigers behind bars....thats makes it easer to poke him every once in a while......LOL[]

No, not really for once. It's actually the exact way I run my G51 in a competition CL stunt plane where we need total reliability and it's a point of honour to get one flick starts .

But just about everything I do is supposed to be wrong. There's no nitro which everyone says helps an engine to start. There's a lot of oil (there's a genuine reason for this but beyond the scope of this discussion). The plug happened to be the first one I picked out of my junk box which worked perfectly so no need to mess with a good thing (ok, maybe I was lucky there ). The engine is inverted which everyone knows makes them hard to start.

So why does it start so easily? I think there are 2 reasons. The first is that I know the needle is set in a proper range and it's set rich. An engine will always run if a bit rich. But I think the most important thing is that from trial and error I've found the exact way the engine needs to be primed. Not just how much fuel to get into it but how to spread that fuel through the engine and how the engine feels when the prime is just right. This is something you can never do with an electric starter and it's why I taught my son how to hand start first before letting him use an electric starter.

With jester's engine (the way I read it) he's done the rich break in with no problem starting it. But at the end of the rich running (4 stroking?) he's immediately tuned for just below peak and this is when the problem started. I suspect it's got more to do with the idle setting now.

MajorTom, no worries mate! Yank the chain any time. Hope the Big Moki is doing well ... they are fine engines ... if castor was used in the lube package you will probably have no damage to the piston/liner fit.

Check1st .. loved the comment! A sense of humour is a must in these forums ... something that is easily forgotten.

(edited for typo's)

I haven't changed the idle needle at all since I took it out of the box.
I'm using 10% nitro, 18%% oil- 1/3 castor. It's what they had at the shop.

Is it normal for a new ringed engine to get easier to flip past the compression after the initial run in? My impression was that was supposed to get harder since the ring fits the liner better.

I suspect a lean idle too.

He went from sloppy rich to leaning the high speed for just off peak. That effected the idle too. But, he's made no adjustment to the idle screw.

Richen the low end 1 or 1.5 turns and see if it'll start.

You can always tell when a glow engine is too lean on the low end. It won't start with a flip. They will sometimes start with an electric starter, and idle okay for a short time-- but when you go to throttle up--they abruptly fall on their face and die. Sure sign of a lean idle mixture.

Most engines are a bit finicky for about a gallon. It takes a bit for them to break in fully and seat in real nice. I set my idle screw for just a touch rich (maybe 1/4 turn rich from perfect) after my initial break in and fly it like that for about a gallon or maybe 1.5 gallons. Then tweak the low end for absolute perfection and rarely ever touch it again.

Taking note of the fact this is a new engine (almost new), my first recommendation would be to fly it for at least a gallon or two with the high-speed needle set just beyond the transition between four-stroking and two-stroking. That means start with the needle opened maybe three turns, get the engine running, give it a couple minutes to warm up, then turn the needle in to the point where you get a fairly substantial increase in rpm with just a couple clicks of the needle. The ringed Supertiger will get stronger with every gallon over pretty much a full season. I would be in no hurry at all to tune close to peak; sneak up on it maybe one click per flying session.

Every session, before you take to the air, do the nose up test: with tank less than half full, run the thottle wide open and raise the nose of the plane so it points straight up. As long as the engine continues to run strong, you're good to fly. If RPM sags at all when you lift the nose, open the needle a click or two and repeat. The needle must be rich enough so that when you go nose up, the engine still draws ample fuel. Engine has to suck harder when the carb is higher than the fuel level in the tank.

Second recommendation would be to add a couple ounces of castor to a gallon of 18% lube fuel. You can get a bottle of castor oil from Sig if your local hobby store doesn't stock it. I would use 20% lube with significant castor (either all castor or at least 1/3 castor) for the first couple gallons. After that, total lube 18% is OK, blended 80% synthetic/20% castor minimum, or even continue with all castor for the life of the engine.

Third recommendation relates to idle needle. The test for good idle setting is to let the engine idle for at least 30 seconds. Idle meaning you can set the engine on the ground and RPMs are low enough so that the plane doesn't pull forward. After idling for 30 seconds, and with the plane tethered safely, rock the throttle to wide open and see what the engine does. Rock the throttle means don't snap it forward, move it up smoothly with maybe a half second transition time. If it picks up RPM smartly, with no hesitation, your idle needle setting is fine. If it sputters and stumbles, idle needle is rich. If it dies right away, or hesitates and only slowly comes up to speed, it's too lean. Proper setting should allow the throttle to respond almost instantaneously, without hesitating, without sputtering. The reason for idling 30 seconds is that with a rich low end needle, excess fuel will puddle in the bottom of the crankcase; then when you open the throttle the excess fuel gets sucked up into the combustion chamber and gives you an over-rich condition that takes a few seconds to burn off. If it doesn't puddle, the 30 seconds will prove that. If it doesn't cough and die, the strong transition to high throttle will prove it's not too lean.

Later in the season, after you've burned at least a few gallons flying definitely on the rich side of the high-speed needle, you can start thinking about tuning for more speed and power. That would involve the 'pinch test.' When you're at that stage, come on this forum and ask about the pinch test, or get one of the guys at the field who's good with two-strokes to help you with that. Even with the pinch test, the nose-up test still applies. You can't ever be so lean on the high needle that you lose RPM with the nose high.

Ideally, when your high end needle is properly set, it will be rich when flying straight and level, and then lean out somewhat but not overlean when you go vertical up, and it will do this with a low level of fuel in the tank--1/4 full or so. So when you need maximum power to go straight up, the engine will automatically respond (along with your throttle stick) to add power when you really need it.

I would strongly advise against trying to accelerate this process. The Supertiger line will basically run strong for a lifetime if it' not abused during the break-in period (or after). Abuse means foremost, don't run lean; don't run with too little lubrication; don't let the engine overheat (caused mainly by too lean, too little lube).

A high end needle that is definitely on the rich side but past the four-stroking into the two-stroking setting (over the hump, RPM-wise) will perform with maximum reliability (no fear of flame-out or deadstick). If you don't have enough RPMs to fly your model at such a setting, then you have too big a prop or too small an engine for your model, or both. This kind of setting will not give you the best fuel efficiency, but you can work your way out of this minor drawback as the season progresses.

This is my syllabus for Two-stroke Engines 101.

Thanks for typing all that out. It sounds like I did jump the gun on tuning because I am not far under peak RPM on the high speed at this point. I'll richen it back up to where I was doing the break in and see what I get. I'll also open the idle needle some too if that doesn't get it going.

Update: I had a "duh" moment and realized that I own a multimeter. So I checked the glow driver and it only was putting out around .8 volts. Took it apart and found some crud where the battery connects. Now I've got 1.25 or so and a white-hot glow plug.
I richened the HS needle a tad and got it started with only a few flips. I'm continuing the break in with a rich mix and will probably fly it next week.

This annoying newbie thanks all you guys for the help.

Nitro does not make an engine easier to start. People assume nitro is more volitile than methanol. But it is not.

We were all newbies once, and depended on others to guide us, so no annoyance at all. Glad you got it resolved, glad you reported it here, hope you have lots of good flying!

Me too. I'm going to start training in a couple of weeks.