Hi Mates:


Would a 40 degree difference in temperature and less humidity have a profound effect on my starting drill?

The last time that I ran this Diesel it started first flip by adding 4-5 drops of fuel into the engine via the ehxhaust port. choke to get the fuel to the NVA. Flip the prop and an easy start. Today, no such luck! I did a lot of flipping today! Lol Do I need to spend some time learning a new starting drill for the warmer weather?

Tia,

Frank

Has your fuel gone off? It should start regardless of the weather IMHO.

It shouldn't have the slightest effect on your "starting drill", however that drastic a weather change could have a dramatic change in the compression and needle valve settings required to get the engine to start.

Just richen it up, knock the compression setting right back, and re-establish a set of settings where it will run again.

Just check that the contra piston actually does move when you back off the comp.

Four or five drops 'into' the exhaust port?

Sounds like that much might flood any schnuerle ported single exhaust diesel.

If you are talking about your 20/15, I find mine also need to be quite wet to start.

20/15's seem to be quite different handling to most of my other radial ported diesels.
They don't give as many clues that they are ready to start.
Tend to be a bit all or nothing, seeming dead then suddenly bursting into life.

They really like to rev but I would not class them as easy handling.

Well they don't have Oliver Tiger starting manners, but mine are ok. After the initial warmup run they usually start first or second flick.

I find that much of the difficulty getting them to go after they've been in storage or not been used for a few years, is getting rid of the ATF (Auto Tranmission Fluid) in the upper cylinder and clearing the NVA of accumulated ATF and dried Castor. ATF does seem to keep the races free and unclogged though.

You really do need to take the engine out of the model and soak it overnight to do this.

I'm usually too lazy and so waste ten minutes flooding them to wash the insides clean, unflooding and blowing the NVA clear. .:-(

Hello All:

Today, I rethought my starting drill for the ST G20/15D. Here is what I learned. Cold engine start: Choke to get fuel to spray bar. Place ONE drop of fuel in the venturi. Starts in 2 flips everytime!

Hot start: Choke 6 times and it starts in a few flips!

The weather today was 72 deg.F so perhaps I was using too much fuel to prime the engine.

Oh I almost forgot one small detail! I replaced the "O" ring on the venturi. Perhaps this was the source of my problems? The old one was loose enough to permit the venturi to turn while the engine was running!

Can not wait to try this engine to see if it runs like a Tigre!

I too have been using ATF as an after run oil and I discovered that the engines start much better if I flush the ATF from the engines. ATF must not like to burn! Lol

Stay well my friends,

Franchi

ATF oil is an oil for automatic transmissions, it was never meant to be used in the combustion part of an engine and it is not dissolved by glow or diesel fuel. It can possibly be used for long storage/conservation of engines but not in between flights or weekends.

Try a dedicated after run oil instead, these are compatible with our model engine fuels and gives you very easy first-starts.

Hello Mr. Cox:

Thanks for the reply.

Perhaps a straight 10-30 synthetic engine would be a better subtitute than ATF, I will try it to see if it makes the engines start better.

I became suspicious of ATF when after I flushed both glow and Diesels with carb cleaner and primed them with fuel, they both started much easier! Perhaps I will use the ATF only for long term storage.

Stay well,

Franchi

I use Rislone oil treatment. It gives green exhaust for the first second or two after starting.

A tangential story. I was flying my Dmeco Sportwing with ST G20-15 in control line Old Time Stunt at a Sig control line contest. I foolishly set my fuel can sit out in the hot sun. I could not get a long enough run to finish the pattern. I was using one of the Sullivan black bulbs for filling. I filled it with fuel, clamped the tube off and put it on ice. With the cool fuel I finished the pattern with no problem.