ESE's works engine tuner

[pete376403]

I used a 38mm Mikuni on a 500 jawa speedway engine (four stroke, forgive me) on methanol. As far as I know the float valve was standard size but there was a horizontal slot cut between the inside of the bowl just below the valve seat. The theory was that the tapered valve flowed enough, but the bottleneck was between the triangular valve shaft and the round hole - the slot bypassed this. Whatever, the engine could run 4 laps at full throttle without starving.

[190mech]

I made a short vid of Wobbly's capacitor mod on a test bench a while back,the results can be seen;
https://www.youtube.com/watch?v=qIf4loTFeiw

[SwePatrick]

I used a 38mm Mikuni on a 500 jawa speedway engine (four stroke, forgive me) on methanol. As far as I know the float valve was standard size but there was a horizontal slot cut between the inside of the bowl just below the valve seat. The theory was that the tapered valve flowed enough, but the bottleneck was between the triangular valve shaft and the round hole - the slot bypassed this. Whatever, the engine could run 4 laps at full throttle without starving.

I use this one:


But i still had some issues, probably due to to much angle on the carb.

[husaberg]

I made a short vid of Wobbly's capacitor mod on a test bench a while back,the results can be seen;
https://www.youtube.com/watch?v=qIf4loTFeiw

you can add a variable one. Almost every old transistor radio has one.
As outlined here.
https://www.kiwibiker.co.nz/forums/s...post1130181478
#its in the attachments,click on them three times

[acr]

I made a short vid of Wobbly's capacitor mod on a test bench a while back,the results can be seen;
https://www.youtube.com/watch?v=qIf4loTFeiw

Yes 190mech i first saw your you tube video and thank you for taking the time for making and putting up the video, the the reason i started playing with this cap mod is because we have alot off the suzuki GT80l and suzuki GT80 x3 1980-1982 mod engines / bikes we have imported from Germany .The Germans have been very busy to keep the power down to 6hp and max 80kmh they have removed the piston port from the cylinder so it only has a small reed to feed the engine, the ignition on these bikes has the CDI system but with a pickup inside the flywheel but it still sparks every 180 degrees 19deg BTDC and 19deg BBDC i have marked up the flywheel with degree markings and when running from 1000rpm up to 10000rpm there is no movement at all not even a wobble , very constant at 19deg and with the Cap mod i get the same 9-10 deg retard as you did these CDI systems are very rare /exspensive used and not sold by Suzuki any more .So i buy some sets from jaycar the motorcycle CDI kit KC5466 soldered up 1 last Sunday and tried it on the Suzuki and it started and i have not moved the stator plate at all but the Jaycar CDI runs at 25 degrees advance on idle and on high rpm it goes down to around 17degrees advance then i had to play with the cap mod again it idles at 25degrees and at 2-3000rpm it goes up to 30degrees advance after that it starts to retard down to 20 degrees this was with the DC cap with the ac/dc cap little happened i will look more into it later this week so it looks like the Jaycar KC5466 is a good/better replacement for our GT80s than buying an used old CDI unit

[jbiplane]

some sets from jaycar the motorcycle CDI kit KC5466 soldered up

I tried for years different ignition solutions from known brands including
Italian Seletra, IDM
German PVL, 3W
Chez Imsoft, Vape, MZ
Belgian HPI
I used EFI solutions of Ecotrons MotoEFI Microsquirt NanoEFI and had a bunch of specific problems of components compabilities.

So finally, my team created universal EFI + ignition solution, which can use wide range of easy to get components and tune up everything from laptop including multidimensional fuel maps, ignition maps.
It can manage any 2stroke or 4stroke with any cylinder layout (inline, V, boxer ...) using the same circuit board.
It can use very different fuel pumps, fuel nozzles, ignition coils to get max of any engine. Its possible write complete engine history in logs for analyzing.
It don’t require expert knowledge to setup and operate.
We tested it for UAV (in air) and interesting to try it somethere else

[peewee]

I used a 38mm Mikuni on a 500 jawa speedway engine (four stroke, forgive me) on methanol. As far as I know the float valve was standard size but there was a horizontal slot cut between the inside of the bowl just below the valve seat. The theory was that the tapered valve flowed enough, but the bottleneck was between the triangular valve shaft and the round hole - the slot bypassed this. Whatever, the engine could run 4 laps at full throttle without starving.

heres the one I use, which appears to be the same one swepatrick uses. so you made a slot like in this pic so more fuel can go past the needle ? well I also discovered today that I don't think drilling the 3.5mm hole larger will do any good. the diam at the base of the needle taper is barely over 3.5mm. so enlarging the hole beyond 3.5 would just meen the needle would go into the hole instead of the needle taper sealing it. if that make sense

[pete376403]

It was long ago (about 35 years) but IIRC the slot was cut where I have marked in the picture. Not sure if this is the correct model carb, it had a round slide.

[Jannem]

Got the bike up and running with Ignitech and roads are beginning to melt. Hopefully I can soon begin to test stuff.

I just seem to come up with more wacky ideas than realistically have time to test, so here's one... 24/7 reeds have been confirmed to work, but slightly tough to implement in your garage, unless very well equipped one.
Thought about getting some very small gauge ptfe-tube which is available for transformer insulation from the Chinese web shops for peanuts and putting multi filament fishing line (which doesn't stretch much) through it. Something like .2-.3mm line can take several kg of force. Simply make tiny cables (close fit and long tubes to minimize possibility of vacuum leak), which you can fish through a small channel ground into the reed block, between the block and the carb. Epoxy tubes in place, glue line ends to the petals and use a Ignitech triggered solenoid to pull the fish home at desired rpm.
No return springs needed as the petals are springs themselves and the line doesn't really add any real weight to the petals.

Which gets me to the question part:

Any tips on solenoids to use with Igni not requiring extra resistors to limit current either for the box or solenoid itself?

[Muhr]

Got the bike up and running with Ignitech and roads are beginning to melt. Hopefully I can soon begin to test stuff.

I just seem to come up with more wacky ideas than realistically have time to test, so here's one... 24/7 reeds have been confirmed to work, but slightly tough to implement in your garage, unless very well equipped one.
Thought about getting some very small gauge ptfe-tube which is available for transformer insulation from the Chinese web shops for peanuts and putting multi filament fishing line (which doesn't stretch much) through it. Something like .2-.3mm line can take several kg of force. Simply make tiny cables (close fit and long tubes to minimize possibility of vacuum leak), which you can fish through a small channel ground into the reed block, between the block and the carb. Epoxy tubes in place, glue line ends to the petals and use a Ignitech triggered solenoid to pull the fish home at desired rpm.
No return springs needed as the petals are springs themselves and the line doesn't really add any real weight to the petals.

Which gets me to the question part:

Any tips on solenoids to use with Igni not requiring extra resistors to limit current either for the box or solenoid itself?

http://www.pjme.co.uk/acatalog/April...ve_Parts_.html might work?

[Greg85]

Well finally boys and girls here is the evidence of what happens when you ceramic coat an Exhaust duct.
The duct was coated with TBC ( Thermal Barrier Coating ) by HPC as is used to coat 4T piston crowns and exhaust pipes.
It was masked off about 10mm into the duct such that the surrounding metal of the port itself would not overheat and create bore distortion.
The result is a drop of about 1Hp all the way up the front side, but more importantly the egt at lower rpm is about 50*C hotter.
From this area upward the deto level was over double that of the stock uncoated cylinder, and under normal test conditions I would have richened the jetting
to try to get back to the same deto level - obviously to the detriment of an extra power loss.
But this test shows that the actual top end jetting was all but identical.

Based on this I now firmly believe in changing the cylinder cooling regime ( TM KZ10C ) to increase the water flow under the duct, and to extend that cooling right out
to the back of the pipe spigot flange face.
I am permitted to machine say 5mm off the cylinder duct exit - and increase the flange thickness by the same amount, allowing a water passage within the fixing flange
to lengthen the cooled length of the exit flow.

i wobbly here are the crankcase of the last tmkz10c black look at the picture they have machined a small part of the crankcase or there is the crankshaft to put more volume, why this place? it is not better to concentrate the volume under the transfers ? thanks

[wobbly]

There are two things in play here.TM have machined the case with enough diametric clearance between the wheels and the rod to reduce parasitic
viscous drag around the surfaces.
And the slot across the covers over the crank starting from the reed exit is there to allow flow outward of mixture trapped within the crank and the machined clearance area.
In the pic the crank spins clockwise,throwing mixture out under the piston.
It has nothing to do with increasing case volume,as I have machined 5mm off the reed mounting face, run that on the dyno and lost power.
Then I added a 5mm spacer plate, this increased power as per the stock baseline ,then I added another 5mm spacer ( making the case bigger than stock ) and lost power big time.
The reed, when fully in has no obstructions, or lift issues, and it does not compromise the boost port entry.
The engine simply does not like a case volume change - end of story.
I tried making the petals softer, to suit the bigger case, and stiffer to suit the smaller case - no free lunch to be found.
Really pissed as this test took days of work to complete with no result at all.

[wax]

There are two things in play here.TM have machined the case with enough diametric clearance between the wheels and the rod to reduce parasitic
viscous drag around the surfaces.
And the slot across the covers over the crank starting from the reed exit is there to allow flow outward of mixture trapped within the crank and the machined clearance area.
In the pic the crank spins clockwise,throwing mixture out under the piston.
It has nothing to do with increasing case volume,as I have machined 5mm off the reed mounting face, run that on the dyno and lost power.
Then I added a 5mm spacer plate, this increased power as per the stock baseline ,then I added another 5mm spacer ( making the case bigger than stock ) and lost power big time.
The reed, when fully in has no obstructions, or lift issues, and it does not compromise the boost port entry.
The engine simply does not like a case volume change - end of story.
I tried making the petals softer, to suit the bigger case, and stiffer to suit the smaller case - no free lunch to be found.
Really pissed as this test took days of work to complete with no result at all.

Ahh but any data is good data. At least you know not to bother looking there anymore.
You should have machined it 5mm shorter as you did then anodised the spacer you used to bring it back to std. Every one would have looked at the spacer and made one not knowing the intake was shorter.

[wobbly]

Ha, thats exactly what I did, we even got protested but sadly for them 1 : the rules allow intake modification 2 : we won the Nationals 3 times with that spacer in.
That was on the B model, now I run C models they all ask where the trick spacer went - I say Franco changed the case volume ( which he didnt ) to get more top end, just to add to the confusion.
PS - changing the case vol gave big differences in egt , this was when Jan had told me about making sure to rejet for any change to restore the egt to be equal.
I would have been really up the garden path if I hadnt done as he suggested.
Its completely second nature now when testing anything.

[wax]

Ha, thats exactly what I did, we even got protested but sadly for them 1 : the rules allow intake modification 2 : we won the Nationals 3 times with that spacer in.
That was on the B model, now I run C models they all ask where the trick spacer went - I say Franco changed the case volume ( which he didnt ) to get more top end, just to add to the confusion.
PS - changing the case vol gave big differences in egt , this was when Jan had told me about making sure to rejet for any change to restore the egt to be equal.
I would have been really up the garden path if I hadnt done as he suggested.
Its completely second nature now when testing anything.

I love doing that, putting something on that makes no difference to take the attention away from what you're really doing the makes the difference