"Derestricting" *THEORY*, YZF-R125/WR125/Rieju RS3

[Riejufixing]

Specifically and only a theory question: "how does it work, not just what does it do".

Different machines sharing identical engines, the Rieju having a carburettor, the others being EFI.

There's mention on t'net of "disconncting a wire to give a 20% performance increase", super wow like wow shit man do it now and ram something up your exhaust pipe and then superglue yore nose to the speedo..... do 95 mate! But back to reality.

What's the theory? The "wire" to the CDI does what? If it controls some sort of "mapping" what does the mapping do? It could control ignition advance, but not valve timing or anything exhaust side on these engines for obvious reasons, and the Rieju has a carburettor rather than EFI so whatever could be tweaked there? Is it "a thing" on EFI engines but not curburetted ones? Is it something to do with limiting revs (although in low gears this does not seem to happen, and there's no "what gear are we in" sensor that I know of)?

So is there any truth to these clims, if so how does it work, or is it a load of old Horlicks on these machines?[/b]

[Ste]

Best way to derestrict it is to upgrade your license.

[Riejufixing]

[-]

Are they even restricted as a 4T?

15bhp is about all you'd expect normally. It's not a 2T with twice the power sitting there, ready to be unleashed.
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[P.]

With the engine being a completely weak tin box, I'd not want more than 15hp out of it.

It is very likely it's hear say, otherwise everyone would be razzing around on them.

[Easy-X]

The brakes kick in automatically at a certain speed

I can only speak to 50cc engines but the magic "justcutonewiresuperquicktrustme" trick is actually a thing... but only for the simple CDI restrictions on el-cheapo Chinese scooters and the like.

But EFI probably has the restriction baked into the map.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Riejufixing]

[Riejufixing]

[MarJay]

I’ve never read anything anywhere to indicate that any of those bikes are restricted.

Maybe some chavs on chav forums or FB groups say it, but I remain unconvinced.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Riejufixing]

[Sister Sledge]

You just know Tef is gonna come along and mention being in the army and old bike tinkering..

I always saw it this way: 2T bikes = Far easier to mess with. 4T bikes far more complex and lots more to go arse up or get right for more power.

I'm unsure for those engines but it's many ways. Maps, rev limiters and even fuel limiters of sorts. Remember too that you'll have actual mechanical limitations such as valve size, valve timing and the gap by how much a valve opens. Cams fix part of it but then add VVT the limitations of valves actually having time to close before compression takes place.

In other words I dunno but I'll grab some popcorn and watch from the stands on this one

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CCM 404 DS

[Riejufixing]

[P.]

A remap is usually done to turbo vehicles so irrelevant in this case.

A power commander could eek miniscule gains.

Cutting a wire will do nothing and 100% know that this forum would know of it.

The 2nd half of my post outlined that, but the engine will be proper scrap with 0.5hp more. Can't wait to see people try and push that tin foil cylinder.

[Fizzoid]

[Sister Sledge]

Paddy is hitting on it - take or make moar power and suffer the consequences. A very good example is a DRZ400 engine compared to something orange and more powerful. It's that fine line that's overstepped.
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CCM 404 DS

[Fizzoid]

[Riejufixing]

[redeem ouzzer]

I would assume it effects the ignition curve if it does anything at all. It’s one wire, that’s all it can be really. In the same sort of way my GSXR400 has two CDI maps, one of which retards the top end so it won’t crack 112mph. Triggered by one wire’s resistance to earth through the gearbox sensor.
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Be a REAL MAN!

[stevo as b4]

This is the first time I've ever heard of this on the Yamaha/Minarelli LC125 engine. As said the only thing that the wire disconnect could do if it's a real thing is either change the ignition timing map (some KTM's and other competition bikes have a second map that un-plugging a connector from the CDI will activate).

The map might be a different rpm rev limit (not going to increase bhp) or a different ignition map for different fuel or configurations.

Personally before spouting to the world on YouTube I'd want to be beyond being able to be proved wrong by doing a back to back dyno test with this wire connected and then it disconnected. I personally don't think it's doing anything and if the author doesn't know otherwise it might be a sensor connection?

These motors aren't restricted IMO and the 14.6bhp they make is designed to comply with 125 legislation. There are some tuning gains to be had with aftermarket parts. (Scorpion quote +1.2bhp with a de-catted full exhaust system on some bikes with this engine)

The fact for me remains that BSD dyno tested an R125 for superbike magazine years ago and found about 12.5bhp r/w.
They then fitted the full Malossi 180cc kit with a performance cam, exhaust system and piggyback ECU. After tuning they just touched 18bhp r/w. This to me shows the available potential in.this engine with almost another 60cc and all the commonly fitted tuning parts.

They said that if they did some head work and looked at fitting bigger intake valves they thought that it would take them to around 21bhp, but they'd have to flow bench test the head and see how much airflow improvement it would be capable of.

Personally if I was a 17yr old kid wanting a new pinnacle 125 for 2-3years and was of a diligent nature regarding maintenance, then I'd be more than happy with 18bhp for 3years or until I could obtain an unrestricted licence.

The Rieju 200's can't be claiming more than 22-24bhp at the crank I would think? The carb engines should not make any more power than the EFI motors are capable of, unless they use a much bigger carb than the throttle body size fitted to EFI engines.