Electric Starting A Four Stoke Glow Motor?

[Dai Fledermaus]

The November issue of RCM&E arrived yesterday, and I was interested in reading the concluding article in Steve Hargreaves series Going Glow. However instead of throwing light on the subject of electric starting a glow motor, it's left me more confused.

Steve seems to make no distinction between electric starting a two stroke and a four stroke engine, yet I have read elsewhere that if you use an electric starter on a little four stroke like the SC/ASP 30FS, you do so at your peril no matter how recalcitrant it might be. If it floods, then you are likely to wind the end off the crankshaft or bend the con rod.

Coincidentally, I watched a chap, at the weekend, electric start an OS 60 or 80 four stroke, I'm not sure exactly which, and it suddenly locked up. The general opinion from the older hands who gathered around was that the con rod was bent. So where do you stand on the subject?

[Alan Gorham_]

At risk of sounding prejudiced....I don't use an electric starter on any of my IC engines (Diesel/Glow/Spark - 2 or 4 stroke).

They all start by hand and I am happy I will never damage them by use of a starter.

[Ian Jones]

I nearly always use an electric starter on everything from an Enya 09 to SC FS180 and everything inbetween. The only exceptions have been a few occasions when the starter battery has got too low to turn an engine and I've had to resort to a stick .

Either way care and attention to safety comes first which includes trying to avoid locking the engine as that in itself has safety issues.

Ian

[David Davis]

If you try to start a flooded engine with an electric starter you'll run the risk of breaking something or at least bending the con-rod. If your engine is flooded, remove the glow plug, disconnect the fuel feed if possible, open the throttle and turn the engine over on the starter. This will send all of the excess fuel out through the plug hole and carburettor and it works even better if you can invert the model.

Like Ian I use a starter motor on everything except diesels and I've never had a problem. The only engine I've ever damaged was an HPVT 21 four-stroke. It ran a piston ring in flight because I was using a fuel with too little oil in it, plus I'd probably got the engine running too weak.

Nothing to do with the starter motor.

Curiously, I own an OS 40FP which prefers to be started by hand.

[john stones 1 - Moderator]

I simply turn my prop over by hand to check it's not fuel locked before using a starter, no probs.

John

[Martin Harris - Moderator]

No need to take the plug out David - tip the model so that the exhaust is downward and gently rock the propeller until it will turn -turn it a couple of times in the correct direction to ensure it's crankcase has emptied and then tip the model up so that the accumulated fuel drains out of the silencer.

[J D 8]

Posted by john stones 1 on 14/10/2014 13:53:15:

I simply turn my prop over by hand to check it's not fuel locked before using a starter, no probs.

John

I do the same,no probs.

[Vecchio Austriaco]

Never had a problem. Use a weak starter and the flooded engine will rather stop the starter than break

[cymaz]

I do use a electric starter for a four stroke! After turning it over by hand

. Always hand start a 2 stroke.... Video here

Edited By cymaz on 14/10/2014 18:58:35

[Jon H]

I hand start everything unless I cant get to the carbs to prime it first. Then I use my beefy 6:1 geared starter as the engines in question are pretty big! The jist of it is however that you can hand or electric start almost anything, but if you electric start any flooded engine you will most likely throw the prop or cause damage.

When hand starting I use the back flick method unless the engine is hot or a diesel.

[Peter Miller]

I use an electric starter on everything, back in the control line days I always hand started engines. Not now.

I use a CMB starter with a built in 6 cell NiMH battery, starts everything up to 52s two and for stroke. The main reason is that it is much lighter to carry. At home on the bench I use a full size starter.

IOf you fill the crankcase on a two stroke, turn the model over clockwise while waggling ghe prop. This allows the fuel to tavel up the transfer port into the cylinder and then out through the exhaust port. rotate the model at least twice and the flick the engine over.

[Peter Christy]

I had to use an electric starter on my little OS 20 4-stroke - the thing was impossible to start by hand! It was an inverted installation too, but I never had any problems with it locking up. A couple of chokes, a couple of flicks to make sure it wasn't flooded, and off it went!

Flick it by hand, and you could be there all day, with nary so much as a "pop" from it........!!!

--

Pete

[Jon Laughton]

I start OS 120 FS and Magnum 180 FS with a high torque starter without any problems....there seem to be some old urban myths here?

[Jon H]

engine damage caused by electric starters is no myth. there are just certain circumstances (flooded engine) that cause it. Also 120 and 180 4 strokes have seriously hefty conrods, its a different story on something like a 20 or 30.

Its not just us either. Anyone with a radial engine in a full size aircraft will pull it through a certain number of times to clear oil that collects in the lower cylinders as this can cause a hydraulic lock when the engine fires.

Edited By Jon Harper on 15/10/2014 15:43:21

[Adrian Smith 1]

I must admit I start both my OS120 FS pumpers with and electric starter, have done so for years. The key here is correct priming by not overdoing it. Over time I can tell by listening to it when turning the prop a couple of times whether there is too much of a "squelch" before applying the starter. You hand swingers have my admiration as in the beginning I lost the will to live trying hand start engines. Indeed the manuals for my gasser OS 33GT and OS 60 GT recommend electric starters to start these engines, which they do with in a couple of trigger squirts. Didn't need any encouragement, why make a simple job difficult? However, I can understand some of the smaller four strokes need to be treated more gently!

[..]

As Adrian suggests I find its all down to the priming. On my pumped engine I find a few " blips" with the starter helps draw the fuel through.

It's nice to get an engine to fire by hand or stick in my case but I see little point in not at least having a starter as a backup, there are a couple in our club who could have had a good flight in the time they waste "flicking"

[Alistair Aardvark]

I can easily start my glow 4 stokes by hand, actually chicken stick, on a test bed. The main reasons are, it's easy to prime, and hydro locking is more difficult. I have 3 types so far Saito 125, and 82a and a YS DZ160. Generally a few reverse flicks off compression does it.

Priming the Saito engines is harder when in the cowled airframes I have, so really a starter is the only option if you want to get flying and like you fingers. On these engines i have a JP 120 size geared starter on 12v battery. The technique of manually turning the engine backwards/clockwise against the compression, pushing on the starter and pressing the button works fine. I've found no need to pre-run the starter before engaging with the spinner, in fact I find this difficult and ineffective

The DZ160 is a different beast altogether (for so many reasons), the JP starter, unsurprisingly, can't do it. So I bought a Just Engines 6.5:1 geared starter. This will easily turn over the DZ. However, the starter speed is too slow so as the engine kicks into life it fights the starter, causing all sorts of pain with kick back and loosening of nuts.

There are two solutions as I see it:

1. Attempt starts in bursts i.e. as the engine fires pull off the starter, sometimes it will keep going sometimes not

2. Buy another battery to get 24v so the starter runs faster. This is a better solution

I had tried using the 6.5:1 geared starter on the Saito 125 - bad idea, far too slow and the engine showed its dissatisfaction by throwing one of its push-rods out of the rocker arm - took me a while to spot that one. No permanent damage though.

Dave