Piston meltdown... again

[RZtuner]

Download the testing guide from this page:https://www.motionpro.com/product/08-0071

I use 6 psi and expect some parasitic loss, 1 psi per minute is acceptable. The power valve seals are usually the culprit as the design is poor. The keyway on the sprocket on the RS end of the crank can also leak. Seal it.

[jumjum01]

Engine rebuild is now complete and the bike is back on the road. I did some testing switching back and forth between stock ignition and Zeeltronic settings (more advanced timing in low/mid rpm). EGT goes high way quick with stock ign. Is this because combustion happens later and the heat goes in the pipe instead of the combustion chamber? (wasted power) And does this mean that there is less chance of meltdown when the heat goes in the pipe and not in cylinder even though EGT is higher?

[kpke]

Wow. Nice work there jumjum. Good luck on this round. I hope it goes well.

What is going on with your neutral switch? Some sort of mod there.

[jumjum01]

Thanks.. fingers crossed
The neutral switch mod is a DIY gear indicator. I 3Dprinted the base to replace the stock nylon plate and added brass screws for all 6 gears and neutral. I then applied suzukis standard using resistors to differentiate the gears on one wire going to the gear display (adruino based display)
The bike runs great now, but sometimes wets the LH sparkplug when going from cruise to WOT and it kills the spark, I am trying to sort out this issue

[MK]

Going from cruise to WOT is a highly transient process that is hard to control with AlphaN.

What happens is that you more or less have optimized the fuel amount for an equilibrium state of a WOT running engine.

In pure AlphaN going from cruise to WOT immediately increases the fuel amount from low to full.
Then let's have a look on the air side: the CV throttle slides are vacuum operated and need several 1/10ths of a second to open. Until then the engine does not flow significantly more air and thus the plug is drowning in fuel.

So what's the solution strategy?
First tune the slides to open faster. There's small holes that connect the volume above and below the slide. The larger and the more of them, the less damping you have in the throttle motion. Less damping= faster dynamic opening.
A softer slide spring does help here, too.

And then there's two parameters on the software side, that massively help to tune this issue. The rpm and the TPS signal can be added with an artificial lag.
This is quite similar to a PT1 element in a controller.
Playing with that values can "soften" rough signals and also cures the above issue. At least it did in my case and thus you'll already have some values set when you used my msq files.
If you just copied the maps, you need to search and copy the lag settings, too

And I have also added a third cheating option in my bike as I'm using an Ignitech DC CDI P4 where each cylinder is fired by two CDI channels wired into 1 HT coil input. Doubles the spark energy for a low budget.
This stretched the range of useable AFR ratios to lower values, i.e. the plug is capable to bear more of this overly rich conditions than usual.

[jumjum01]

I solved the problem with fouling plugs. Seems like the throttle cable for the oil pump where not seated correctly in the splitter after removing/installing engine, giving too much oil. Bike runs perfect now. Using af timing gun i properly found the real reason why the piston melted. The timing was waaay to advanced i my previous setup. The flywheel has 2 magnets on a 360 deg. rotation, 180 deg. apart. The ignition setup (microsquirt ecu) perceived the distance between two magnets as 360 rotation, but in reality it was only a 180 deg. rotation. This caused a double up in ignition advance. Looking back I know it was stupid not to have done checkup with timing gun.
I did some testing today with my manual YPVS switch. I can see why some people like the old LC with no YPVS valve, you can really feel the kick when entering the powerband. But below 6000rpm you only really have scooter power
I feels like the bike makes the most power by fully opening the valve at 6000rpm instead of opening gradually. When holding a steady 6000rpm in 2nd gear and wacking the throttle open the bike wants to hoist the front wheel

[MK]

"Feelings" can be misleading.
For my current setup I did some EngMod simulations with valves fully open and fully closed.
Then I picked start/end rpm according to the two rpms with max torque.
Astonishingly the sim with that PV curve showed a slightly higher peak power than the "valves open" sim before.
This is an effect that also occurred on the dyno, so feel free to experiment.

BTW:
When I started with PV mods ages ago without much diagnostics, I got into the same path. An earlier full open rpm and also an s-shaped opening curve made the engine "feel" more agile.
The "more performance" setting was different from the "more fun" setup you now have.

But FYI: Most blade type PVs don't allow such blending of the exhaust timing like the Yamaha YPVS. They usually have a dedicated opening rpm and there's just two positions open/closed. In some cases accompanied by a third position in between accomplished by a multi-piece design of the blade.

[jumjum01]

I found that my new YPVS valves did not open all the way, thats way I could open them fully at 6000rpm. After adjusting them, the PV now opens in 2 steps. Step one at 6000rpm (80%) and step 2 (100% open) at 7300rpm. A small dip in dyno curve going to step 2, but i ran out of dyno time. But still I am happy with the result for a almost stock bike with modified F2 exhaust and EFI.

Second dyno is powervalve fully closed vs. fully open

Comparing F2 exhaust performance vs. the TPR exhaust, which I was tempted to buy

- The F2 makes more power up to 8500rpm, the TPR makes more power from 9500-10000rpm
- From 6000-8500rpm F2 makes +4HP

Guess the Yamaha engineers did a good job on the stock exhaust

[jerele]

When the F2 exhaust "dies", the TPR exhaust is "born". It's that simple. We use TPR only for racing, they are old design, according to the gurus.
But they are made in Andalusia, my land.

I am very interested in the EFI, I follow you.