ESE's works engine tuner

**TZ350** · 22nd March 2013, 20:35

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I am very taken with the Ball Throttle Idea.

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And I would like to try one in the old plenum setup.

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The old plenum suffered from the blars with the short inlet and needed the extension, but the ball throttle may fix that. The other problem with the plenum was fuel dropout puddling in the bottom and affecting the mixture. I fitted a scavenge pump to cure that but never really put any time into it. This time I will use fuel injection and see how that goes.

The plenum was an idea to get around the 24mm carb restriction but 24mm's turned out to be not as much of a restriction as we thought it would be.

But the 24mm will eventually restrict things and I am starting to suspect it plays a part in the over rev deto thing by limiting the crank case filling and case pressure at 13K. My guess is, a Lower case pressure will allow more hot exhaust gas to enter the transfers at high rpm.

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Graph of my 24mm taper bored 24mm vis 30mm conventional carb in a back to back test a while ago. The only real difference was in the over rev area which leaves me thinking that the 24 could be contributing to the over rev deto problem. I will try the 30 on the dyno again next week and see what happens with the high rev deto.

**TZ350** · 22nd March 2013, 21:17

Originally Posted by teriks

This auto ignition was was in gear, clutch out, on the roller at high RPM?
If so, perhaps the auto ignition occurs very late, producing little to no power?

Can you do a test with an all aluminium head?

The cu sheet could act as an catalyst and be part of the problem, especially if you have a hot-spot on it somewhere.

Another good idea to try out.

**husaberg** · 22nd March 2013, 21:25

Originally Posted by TZ350

Another good idea to try out.

Why not wack in some cupfuls of Acetone as well as a eggperiment.
It would only take a few minutes.
It woulds be cool is see if it's all, it's cracked up to be.

**TZ350** · 22nd March 2013, 22:28

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I am going to try making another triple exhaust port cylinder. The EngMod 2T simulation, is with the two side ports closed, red line and open, blue line. I can see some sort of power valve arrangement in my life soon.

**bucketracer** · 23rd March 2013, 09:38

Originally Posted by SS90

Post a video and dyno run of your daddy's latest abandoned project ...

Whether it works out or not, I am sure there will be something posted about it.

**wax** · 23rd March 2013, 09:45

I'm guessing no one tried wasted spark on the dunno to see if there was a gain, I had figured maybe it kept the plug cleaner and well know that two strokes love a clean plug

**husaberg** · 23rd March 2013, 10:32

Originally Posted by wax

I'm guessing no one tried wasted spark on the dunno to see if there was a gain, I had figured maybe it kept the plug cleaner and well know that two strokes love a clean plug

Some one would have i seem to think the RDLC was a wasted spark set up, but i am no Yamaha guy.
I struggle to see how you could achieve a HP gain from drawing yet more energy from the engine to power the ignition than is needed to fire the plug though.
But no clue what the loss would be, maybe make a ignition dyno, and run a firing ignition (under load) and see what it draws to power the ignition dyno.
At the end of the day if you plan to run it for reliability, does it matter if it costs you a HP.
If the original ignition was working properly on competition engine the plug shouldn't be dirty should it.

**wax** · 23rd March 2013, 10:51

Originally Posted by husaberg

Some one would have i seem to think the RDLC was a wasted spark set up, but i am no Yamaha guy.
I struggle to see how you could achieve a HP gain from drawing yet more energy from the engine to power the ignition than is needed to fire the plug though.
But no clue what the loss would be, maybe make a ignition dyno, and run a firing ignition (under load) and see what it draws to power the ignition dyno.
At the end of the day if you plan to run it for reliability, does it matter if it costs you a HP.
If the original ignition was working properly on competition engine the plug shouldn't be dirty should it.

Most of those things I agree with you. Im interested to see if some one has dynoed it and seen a power or loss. As I said I have a choice as to what I do as Im making my own ignition setup for this bike. If some one had dynoed it and found a gain either way then I would be interested in the results. We all know that indexing the spark plug n a two stroke makes a difference and yet you wouldnt think so unless you understand whats causing it. in that case why couldnt a wasted spark system make more or less power

**husaberg** · 23rd March 2013, 11:18

Originally Posted by wax

Most of those things I agree with you. Im interested to see if some one has dynoed it and seen a power or loss. As I said I have a choice as to what I do as Im making my own ignition setup for this bike. If some one had dynoed it and found a gain either way then I would be interested in the results. We all know that indexing the spark plug n a two stroke makes a difference and yet you wouldnt think so unless you understand whats causing it. in that case why couldnt a wasted spark system make more or less power

To tell you the truth i have never seen any definitive back to back testing vs indexed plugs but who can resist the urge to do it.............
All the stuff i have ever seen on it relates to OCD American drag racers running Huge cc clinders with mega cylinder pressures Drag motors on exotic fuels............

**wax** · 23rd March 2013, 11:27

Its worth 1 mph or about 150 rpm on a 701 yamaha superjet. One of the easiest mods you can do as well.

That doest sound like much but you have to have more power to be pulling that higher rpm of course and 1mph when you drag racing up the start straight is worth heaps

**Flettner** · 23rd March 2013, 13:45

That's what I understood to be a wasted spark. But this is done for manufacturing convenience of a twin cylinder two stroke more than anything. I doubt it would be of any use on a single. If you need redundancy use a Ingnitec and run both channels into it. I do this but that's only because I have a dual channel Ignitec fitted. Fire them at the same time through one coil. More energy at the plug ( perhaps only 10% but worth having ). Because the F9 runs on E90, I tell any who asks it's E85 from Gull, spark voltage and rise time are important. Two into one helps, never had a fouled plug yet. Sometimes it's been so rich it will hardly run, the joys of tuning EFI.

TZ350, I'd say you are right on the money!

**TZ350** · 23rd March 2013, 15:08

Originally Posted by wax

We all know that indexing the spark plug n a two stroke makes a difference and yet you wouldnt think so unless you understand whats causing it.

I would like to know more about this as I would like to try it on the dyno, which way should the earth strap face?? towards the ex port or the rear boost port or side on to both, or do you have to find out what your own engine likes??