I just started flying, 16 flights so far. On the 3rd flight I broke the motor mount, and when I replaced the mount ,I also installed an Evo .46 trainer engine, in place of the Supertigre GS40 I had in it.
My question is, when flying, is there always a 3/4 second or so pause when you operate the throttle. I did`nt notice this ,the 3 flights with the Supertigre but I was really wound up the first 3 or so flights and don`t remember.
The Evo has a flywheel weight on it and was running a 11x5 prop.
Or? is it the time it takes the sound to get back to me. I`m a newbie , what can I say lol?

What does it do on the ground? It sounds like idle mixture may be off and causing an acceleration hesitation.

Question, why does the engine have a flywheel??

Your prop is all the flywheel needed. The less weight on the crankshaft the longer your engine will last. Less weight is also less vibration.

You may need to adjust the carb on the engine. A slugish response to throtle is an indication that your mixes are not right. Adjust the high speed first, then the idle. Check for transision between idle and high speed. If it stumbles when you give it throtle, it is not adjusted correctly. Have one of the guys at the field walk you through the carb setup.

Don

A flywheel weight will give you a smoother idle and more consistant RPM (assuming the weight is balanced)
I think more trainers should have them.
Most people who fly don't adjust the throttle except to land or tak off.
With that kind of operation you will see the biggest benefit from a flywheel.

Are you sure that the delay is not due to the sound of your engine needing about 3/4 of a second to travel from your plane to your ears? That would be with the plane about 250 meters away.

The engine runs smooth on the ground,good throttle responce.
The engine is off a Hanger 9 PTS P-51 which comes with the flywheel wieght. The high and low needles have limiters on them so us Newbies can`t mess them up. Also they claim it is broke in at the factory. Runs a little rich but still runs really good.
I thought maybe the added weight of the flywheel slows down the spool up time., but it does`nt on the ground. Just wonder if it is`nt sound travel thing, but being a Newbie ,I keep it pretty close to me.
Maybe I should go back with the Supertigre? I have a Magnum 52 FS that I was going to mount on it but the throttle linkage makes it a hassel to install.
Thanks for your responces, the help is appreciated.

It often surprises people just how far away their planes are while flying. I have seen people crash out in the woody part of our flying field and when they couldn't locate the wreckage, I would go out there and sometimes find it way farther away than the pilot thought it was. Also, people often underestimate how long a second really is. You may be hearing a quarter or half second delay but imagine it as 3/4 of a second.

I have seen an Evolution flywheel and I don't think it is large enough to create a significant delay in spoolup time. There is way more inertia in the tips of even a wood prop.

The PTS engines are NOT broken in. They ARE pre-set but often wrong. They are within a range where they will work but not necessarily optimum. Newbies don't have to mess them up, the factory has done that for you too. What a deal, eh?

Limiters? Nice pieces of scrap metal. That said, they do keep some newbies without instructors from destroying their engines.

Flywheel? Great idea actually. Only problem is that many spinner backing plates do not fit over them well. Not hard to remove though.

It could be sound delay time or some other matter of perception. 3/4 second isn't a very long time at any rate. Now if it were 3 to 4 seconds I'd worry.

Lol!

So true.

watch the smoke when you throttle up. if ya see that right away, but don't hear it rev up at the same time, it's prolly just the time it takes for the sound to travel to you.

If you also hear the same delay when closing the throttle suddenly, it's the speed of sound.

Exactly what I was thinking.

BTW Robbie, what the hell are you doing flying in this weather???

I can`t help it.LOL. I`m building skis as we speak. But the 3 ft snow drifts are making it hard to get to the shop!
I taught my self to fly this week and I know it`s not recommended, especially in this kind of wind.
I have no fear of flying in the wind now, but beleive me I have the utmost respect for it.
Being laid up for 18 months with all these back surgerys I could`nt take it anymore. My doctors talking about an other operation soon and I was afraid I would`nt get to fly much this spring while I recovered. He says it well help me to be able to look up longer, which I`ve found is very impotant in this hobby.
All my life has been involved with wings,LOL I miss it terribly. You seen how I was at the auction, like a kid in a candy store.

I decided to tear the engine down and clean it after my little flame out episode. What I found was the o-ring between the carb and crankcase was crumpled up in the bottom of the throat.
I`m not sure if this was the problem or not, but it probaly did`nt help. Also pulled the pin on the low end stop. It was the same as closed, but that's where it ran the best with the o-ring problem.
Think this was what I was hearing?

the o-ring basically was missing and probably throwing off the idle mixture. With everything where it belongs I'd expect a re-tune of the idle mixture (high end too but only slightly) to be required. This may help with your problem but no guarantees.

Hmmm... When I first started to read this, I thought it was the time delay for the speed of sound, as some others thought. Since someone pointed that out to me, I stopped listening and began watching. Of course, it helped my watching after the Surgeon removed the cataract from my left eye..[8D] .

But, I wonder if that's what was wrong with my Evo 100. There was always a issue with that thing not running well, either upright or inverted. I would get it running, thought it was in tune, then two minutes later, it would not take throttle changes worth a darn. I eventually gave up and put an OS 1.20 AX on that plane and have been happy ever since.

I will have to take a close look at that carb setup now.

Thanks for the info. I hope it helps me out (as well as it does Moondoggie).

DS.