konrad

All you need to do is loosen the two screws that clamp the throttle to the bars. Rotate the entire throttle assembly to the position you want, and tighten the screws.

Yes. The fuel pump uses a mechanical pressure regulator and runs at a constant pressure. The ECU opens the injector for the appropriate amount of time to deliver the required fuel. I've written extensively about the OSSA EFI system here: https://www.ossa-efi.com/home There are tons of details scattered across the website, but I've never described the basic operating principles of EFI. Perhaps I should?

Are you thinking the ECU does something more than just turn the pump on and off? I suppose the ECU could PWM the pump to vary the flow, but I have never heard of that being done.

I'll preface these remarks by stating that I have never touched a Beta 4T carb. But I do have some experience tuning constant velocity (CV) carbs. The thing about CV carbs is that no matter what rate the rider opens the butterfly throttle, the vacuum-operated slide only opens in response to engine demand. This is great because the manufacturer can fit a large throttle bore, and the bike is still easily driveable by a ham-fisted rider. If you make the spring that controls the diaphragm weaker, the throttle connection will become more direct. Look at the design equations for springs to see the variables you have to work with. The simplest solution is just to replicate the standard spring with a greater number of turns (but you have to be careful about coil bind so the slide can still open fully). Alternatively, you can wind the spring from a thinner diameter wire. I have bought spring steel wire from McMaster-Carr https://www.mcmaster.com/products/spring-wire/steel-1~/ but I expect there are other fine sources.

The most likely cause of the lever not returning is an over-tightened lever pivot bolt. Maybe the tip-over exacerbated that? Or dirt is causing binding? Your disassembly introduced a lot of air into the system. I would try to "gravity bleed" it initially. Open the caliper bleed valve (put a hose onto the nipple and direct the fluid into a container so as not to make a mess) and wait. Keep an eye on the fluid in the master cylinder with the cover off. Refill as needed, before it goes empty. When you think all the air is out, try bleeding using your normal technique.

Yes. The potentiometer shown on my website is called a trimmer, or trim pot. It requites ~25 turns to go from one extreme to the other. Also, you must measure the voltage when the trim pot is connect to the controller (because its input impedance will affect the reading).

The PRB does not emit 0 volts when it's off (more like 0.6V, from memory). That, plus the fact that it's very difficult for your finger to apply only a tiny amount of PRB, probably gave you the wrong impression. The threshold for the PRB to start affecting the throttle does not occur until about 1.1 volts. (At least that's the behavior of the firmware in my 2021 controller. Yours may be different.) P.S. That T2 connector is where I guessed the throttle could be plug-in to obtain school maps.

I don't think it's in anyone's best interests for me to provide more information than what's already on my website. It assumes a basic knowledge of electronics that is a prerequisite for making modifications to the bike. But I really want to discourage anyone from using a DC/DC converter in that manner! A DC/DC converter could potentially source sufficient voltage/current to damage the controller if it's improperly wired, improperly adjusted or just plain fails. Stick with the potentiometer shown an the end of the Regen Experiments page: https://www.electricmotiontech.com/home/em-epure-race/regen-experiments#h.7lz2uhjj7x3c The 2023 bike clearly has some wiring differences to my 2021 model that you will have to determine for yourself.

Interesting problem. The first search result for the GG P/N says it ships in 2-5 business days: https://www.ocpoemparts.com/oemparts/p/gasgas/bt20220gg-cka-1/cartridge I find it difficult to imagine a guy who's done 10k forks over-tightened it. How much longer did you make the preload spacer? But even if the spring went into coilbind, I can't see that breaking the damper rod. Can you post a high-resolution photo of the break?

Your issues with the clutch may not be completely of your making. Clutch fiber plates take some time to break in. You can speed the process (and give the clutch a longer life) by perfectly aligning the plates: https://www.electricmotiontech.com/home/em-epure-race/mechanicals/clutch#h.twzu1hiimf5e You could also experiment with different clutch fluids. Finally, my wife tried one of these levers on her Dragonfly: https://www.splatshop.co.uk/trialsolutions-ergo-lever.html It worked so well, I bought one for my EM.

My understanding is that EM allows 2023 models to be upgraded to 2024 specs which would also give you EM Connect. But you must buy a lot of hardware: TCU, display, switchgear. Probably more cost-effective just to trade up to a newer bike. Regarding the school mode on later models. I have the idea there may be two different places to plug the throttle into the wiring harness -- one for standard mode and one for school mode. But that is speculation because I don't have a bike to examine. Regardless, it would be possible to make the throttle less responsive by inserting a resistor in series with the 5-volt reference to the throttle. (In fact, that's how EM implemented the different power modes on their original 5.7.) For example, let's say the controller expects to see a command signal of 4.8 volts as WOT. When the controller sees a throttle signal of 2.4 volts, it will produce one-half of its maximum torque (for that map). If instead, you make WOT produce only 2.4 volts, the torque at any throttle opening will be correspondingly reduced. Research the theory of voltage dividers to understand this.

Well, that is not at all what I expected. I had assumed a ball bearing with an inner race. That is quite possibly a special bearing manufactured for Fantic. I'd suggest taking everything to a local bearing supply company and having a chat with a specialist.

Yes, that would not be uncommon. But I have zero knowledge about Fantic engines, and the bearing could well be difficult to remove due to corrosion.

One more thought. Replace the OE crank bearing with one from a more modern 2T engine that uses sealed packed-in-grease main bearings.

I was going to stay out of this one because I expect any proper repair would cost as much as the bike is worth. Beside the aforementioned sleeve, plasma spraying or welding followed by grinding is what would be done for industrial equipment. A lower-cost option may be to build a working crank from two scrap cranks with different problems. The most critical area is the seal running surface. Depending on severity, an air leak there will make the bike difficult to carburate or prone to seizure. As for a ghetto repair, I may be tempted to try a metal epoxy (JB Weld comes to mind). This would last long enough to evaluate whether a more permanent fix would be worthwhile. Fitting a different seal, or altering the location of the standard seal, is another possibility.

If the map light is not illuminated and the motor is not beeping, the controller is not being enabled. I say this because, if the controller detects a problem with the throttle (for example) it will cause the motor to emit "protest beeps" by the same mechanism that it uses to make sounds when the map is changed. The most likely problem is the lanyard kill switch is not enabling the controller. See: https://www.electricmotiontech.com/home/em-epure-race/wiring-diagram#h.lio6f0vlp8ue I suggest constructing a "failed lanyard bypass" as a test.

Sounds like you need to take a little break, away from the problem. Some of the kill switch wiring does go to the controller. Have you checked the 3A fuse that's by the controller?

The controller is very well protected, so unlikely you killed it. The LED returning to white (neutral) indicates the controller has somehow been power-cycled. This would tend to imply intermittent wiring, or the battery itself is providing intermittent power. If you remove the rear mudguard, you can see a red LED on the controller itself. The following information comes from siliXcon (manufacturer of the controller) and could rule out a failure in the controller itself. https://docs.silixcon.com/docs/hw/esc/Maintenance#verifying-motor-controller-readiness-for-operation

You are obviously a very skilled restorer. I'm curious about the economics of this type of endeavor. 6.7 million views on your Subie restoration in 2 years. Is the process about generating ad revenue, or is it a labor of love?

The above makes a lot of sense to me, especially for the US market. But it presupposes that you are willing and competent to work on your own bike. Read the whole thing here: https://jotagasoffroad.com/company/

I agree with lemur about the 4RT. The problem is that if you find a "cheap" one, it's going to require maintenance. At this point, I suggest trying to borrow a bike to see if you even enjoy the type of riding you are anticipating. P.S. I meant to respond about the new Michelins on the cheap 125. Any amount of road riding will rapidly degrade them. Tire pressure is another issue. It will need to be significantly higher for road riding than trials.

As a wise man once said, "The cheapest restoration you can do is with a camera." You won't know if it's truly a bargain until you ride it.

125 will only make half the torque of a 250. A 125 will be geared shorter than a 250, but maybe only by ~15%. P.S. My compliments on your English. Am assuming it's not your first language.

You have a lot of conflicting requirements. A 125 would be fine for trials. In fact, it would teach you a lot about how to properly use your body to get the most out of the its limited power. I would not want to try to chase down an enduro bike with a 125. But if you pick the gnarliest terrain, you would have the advantage. If your skills as a mechanic are very good, you may be able to find a bargain on an older bike. Each bike must be judged by a pre-purchase evaluation. But in general, you get what you pay for. There will be more wrong with an older bike that will require repair.

These spring rates are suggested by EM for the FACTOR-e, but they would be appropriate rates for the Race as well: https://www.electricmotiontech.com/home/em-factor-e/suspension Trials bikes require considerably less rebound damping than other forms of motorsports. Some information about the Tech forks here: https://www.electricmotiontech.com/home/em-epure-race/mechanicals/tech-39mm-forks