ESE's works engine tuner

[F5 Dave]

Intelijet?

Wob has commented before , what is consensus now for ease at a race meet?

[wobbly]

The SC and Lectron behave in the same way to changes in RAD.
That is way less sensitivity to those changes , I would estimate they are affected about 1/2 as much as the fuel blob producing normal type carbs.
The mechanism is based on the fuel being " sheared " into much finer droplet size by the action of the flat sided needle , and changes in air density change this effect.
Its got bugger all to do with the smoke and mirrors marketing waffle produced by SC about the Aux Venturi above the bellmouth thats connected to the top of the fuel bowl , as a
Lectron doesnt have that but it works in exactly the same manner.
So you would still need to change the fueling on a cold morning warmup , but then only have to change it once later in the day when its steaming hot and the Density Altitude
has increased a 1000 ft.
I would have had to do 4 jet changes in a normal carb to keep on the money.
And that right there is the downfall of the SC , making small accurate main jet changes is all but impossible - the Lectron PJ takes a minute and is repeatably accurate every time.
The Intelijet works well in that it adds air correction, that not only changes the fuel curve it increases atomization.

Edit - I have asked Lectron about adding an air corrector to the PJ circuit ( as SC flatly refused to do this ) and they said they had done testing on this very thing , but felt it added too much complexity
( another tuning variable ) for negligible gain in performance.

[F5 Dave]

Certainly the intelijet is cheaper if you already have pwk. Or even before.

[diesel pig]

I must say I was very impressed by the Smart-Carb Tuning on the you-tube videos they just stopped the motor. Held the throttle wide open and turned one knob on the top of the carb for tuning Right for Rich and Left for lean. I had a quick look at the Lectron site. I must admit I could not figure out how one did the tuning Rod the power jet was obvious but not the Rod to me. So Wobbly, I think you leaning towards the Lectron and one tuning change per day is way easier than four to me. So a Carb with a tuning Rod instead of needles and jets still has my interest. But what size and brand do you think one should be picked by someone who is a keen 100cc 2-Stroke bucketer but no expert tuner?

[wobbly]

So here is my take - you want a tuning rod and you want it simple to change the jetting.
The Lectron also is a very simple scenario for adjusting the rod , but as it has an adjustable PJ thats not even necessary.
They do have a screw needle adjuster setup for the top of the PJ , so a 10 sec screwdriver adjustment of that sounds like you.
They have a needle turn/jet size chart to follow , so thats simple as well.
As for size I think the ideal would be a 34HV as this has a 4mm smaller venturi behind the slide and at part throttle that gives you the response of a 30mm carb.
Perfect combination in a roadrace bucket scenario where you are never going to have a " real " close ratio cluster.

[crbbt]

Look how long it took lectron the add a proper TPS because of "complexity"

[wobbly]

So you tell me how many carbs have ever had TPS on the market , its confined to a super small 2T road race and MX number and the rest are 4T that usually have injection now anyway.
If I wanted a in situ TPS the only 2T carbs are the SPJ on RS125/250 Hondas , and a few of years of MX bikes in the early 2000 that had electronic servo's and or PJ.
Lectron with their new patented needle now have the opportunity to sell larger numbers of units into the older Superbike market and the 4T MX carbureted market.
So their TPS is just an extension of market sales capability , not " complexity " as such - a bit of an unfair criticism in my humble view.

[diesel pig]

One thing I notice when i was on the lectron site was the power jets on there carbs did not appear to be solenoid controlled. Or maybe this is not important to get overrev with tuning Rod Carbs?

and you are right on the gearbox Wobbly, Even taking a advantage of all the micofiche sites on the Web these days. The best I could do was mix and match gears from different models of the same basic engine to get a "closer" than stock gearbox but far from close ratio gearbox.

[jbiplane]

This is another test for my fuel injected 2-stroke boxer using as load air brake = small propeller with adjustable blade angle
2-stroke boxer resonator add just 17% of power, but bsfc become much better

[wobbly]

The solenoid PJ situation I am working on right now. It appears that all the suppliers of the original Mikuni setup are out of stock as the kit is NLA.
I need the solenoid setup for the 350 YPVS racebike I am doing that has just been fitted with Billetron 38HV with twin PJ in place.
These sit dead square on the reed block face using Mikuni ovel carb rubbers - easy free Hp.
The switched jet is a deadly setup for overev , be it just off/on/off or PWM with TPS, available on Zeel or Ignitech's
The Dellorto solenoid used on the RSA I believe was an air control of some sort for a Weber fitted to Fiats - so Im looking to adapt that sort of thing onto the standard Mikuni PJ kit.
Will post the result on here as soon as I have it sorted.

[190mech]

wobbly,
I seem to remember that Jan Thiel said they used off the shelf Keihin solenoid valves on the Dellorto for the RSA. He even gave the part number..

[diesel pig]

The solenoid PJ situation I am working on right now. It appears that all the suppliers of the original Mikuni setup are out of stock as the kit is NLA.
I need the solenoid setup for the 350 YPVS racebike I am doing that has just been fitted with Billetron 38HV with twin PJ in place.
These sit dead square on the reed block face using Mikuni ovel carb rubbers - easy free Hp.
The switched jet is a deadly setup for overev , be it just off/on/off or PWM with TPS, available on Zeel or Ignitech's
The Dellorto solenoid used on the RSA I believe was an air control of some sort for a Weber fitted to Fiats - so Im looking to adapt that sort of thing onto the standard Mikuni PJ kit.
Will post the result on here as soon as I have it sorted.

And that picture Wobbly posted confirms what I was thinking about how to get a solenoid to work on a carb with a power jet that did not have solenoid fitted at the Factory. kudos Wobbly

[husaberg]

wobbly,
I seem to remember that Jan Thiel said they used off the shelf Keihin solenoid valves on the Dellorto for the RSA. He even gave the part number..

And that picture Wobbly posted confirms what I was thinking about how to get a solenoid to work on a carb with a power jet that did not have solenoid fitted at the Factory. kudos Wobbly

My understanding was wn the Aprilia they originally used a stepper motor and it could progressively shut off the flow I assume using a needle valve
It was an idle control stepper motor off a Fiat uno. I think they later went to a Keihin part of an RS125R
DP get a Keihin off latish NSR250, they have a tps and are likely a better size. ALso factory downdraft.
you can get kits for them to give them more adjustability
https://nsr-world.com/tuning/250-tun.../carburettors/
Dave was trying to steer you to a dial a jet
https://thunderproducts.com/product-...ms/dial-a-jet/
https://thunderproducts.com/product-...ems/intelajet/

[diesel pig]

Thanks Husaberg and Wobbly for both your input. Much to think about. The thing I have to keep in mind is being just one guy at a club meeting is to keep the Carb tuning steps as simple and straight forward as possible to keep on top of the two strokes I am running.

[speedpro]

What about using a boost control PWM solenoid to bleed away the vacuum signal from the powerjet? You'd have a normal powerjet circuit but with a T-junction with the solenoid off to the side. When you don't want the powerjet to supply fuel energize the solenoid to allow air to be drawn in rather than fuel to be drawn in via the jet. If it was progressive via the PWM control you would have air mixing with the petrol from the jet before it got to the powerjet tube in the throat of the carb. The desired fuel would get there that little bit quicker due to the airflow which it would mix with plus instead of globs of fuel it would be a mix of fuel and air.

I had a much less sophisticated version on my turbo McIntosh but it resulted in the same outcome. A mixture or air and fuel entered the opening of the carb through the "jet"