EFI remaps, worth the bother on a 125?

[Easy-X]

A while back I had a problem on the faux-cruiser in the really cold weather (performance bad while the engine was warming up) and that was about 80% sorted just by getting the valve clearances right (they were way out.)

But that last 20% is annoying! It translates as a flat spot around 4k revs, below that it's fine, above that it's fine.

From my experience tinkering with the turd scooter it seems my 125 is running a bit lean. Obviously with Euro 4 and Cats bikes tend to be tuned on the lean side for emissions but it feels like it only needs a teeny-weeny nudge to be spot on.

I'm wondering if the cheesy thing to do would be add some restriction to the air intake. Will that even work on EFI? Even so that translates as smooth running engine but less power on a bike that does 0 to 60 in... what day is it today?

So is the alternative to take it to a dyno and get it remapped? That sounds expensive! Thing is I wouldn't be happy giving/selling the bike to someone else without all the kinks ironed out.

I'd do it myself but I've found zero info on programming the Yeson 28s-06 ECU.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[linuxyeti]

Personally, I would imagine it would be cost prohibitive, and not likely to improve matters much, if at all. I've found to some degree treat efi bikes like carb'd bikes, and let them warm up first, leave it running whilst you get your jacket, helmet & gloves on, and that seems to solve most of the problems. Doesn't always work, even with my Triumph America, the engine would still randomly cut out slowing down from motorway speeds on slip roads, or going round roundabouts !! My Mash, would cut out, occasionally, until I started letting it warm up, after I started doing that, never had another cut out. On my little 125 (Mondial) the temp gauge on the dashboard flashes until it's deemed warm enough to ride..

The Superlight is fairly low powered, even by 125 standards, and I guess relatively heavy. Just picked one up for my daughter with 22Km's on the clock, as, that's the bike she wants to move up to when she's 17. Got it for a good price, and rode it home, quite a pleasant ride, but what is it with the indicator buttons !!
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Beware what photos you upload, or link to on here, especially if you have family members on them

[The Shaggy D.A.]

There's a simple adjustment that can be made to the EFI on my Enfield to the Throttle Position Sensor that causes slightly richer running - TPS resting voltage at idle should be 0.6v +/- 0.2v, so can be tweaked up to 0.8v to make it richer (WOT should be 5.0v).

https://www.youtube.com/watch?v=TiX8oFtYZls

Might be a completely different kettle of shite, but I'd be looking at seeing if there's an equivalent on your bike.
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Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[Easy-X]

[Easy-X]

[cb1rocket]

can you even get someone to map it? I doubt it
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Honda H100S2 Rebuild - https://www.bikechatforums.com/viewtopic.php?t=253852

[Easy-X]

Here's a thought: could I do something to the output of the lambda sensor to get it to "lie" to the ECU, just a itty-bitty little white lie?
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[linuxyeti]

[MarJay]

At the price they cost and how much they depreciate, I'd honestly sell it and buy a Japanese bike. Preferably one over 125cc... So I'd spend the money I was going to spend on a remap on doing your test, and then chop the Keeway in for something decent.
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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.

[Easy-X]

[The Shaggy D.A.]

[stevo as b4]

It seems your just trying to correct a tiny lean stumble or hesitation outside of the normal operating rpm range. Maybe an Autist at a loose end desperate for a reason to do some electronic fiddling to satisfy the voices in your head?

And you can't re-map a bike at home as you won't have a clue what to do or change in the maps and what effect it has. You also have no way of measuring CO and oxygen sensor readings, and no way to put the engine under load to simulate a riding exercise. Part of me says your one of them that would buy a wide band kit for £££'s just because you have to know and must fiddle and work things out at any cost to satisfy the way your brain ticks?

But to answer your question yes it's just as worthwhile to re-map a 125 as it is to re-map a GSXR1000. But only if:

1, your making significant exhaust or intake changes, or removing all the emissions control equipment like EGR and catalytic converters etc. Possibly making the bike deliberately illegal for road use, or for racing where there's no emissions regulations imposed.

2, if your doing all of the above for performance and drivability reasons and want maximum power, throttle response and the ideal performance oriented fueling and mapping.

If not yes to both then I wouldn't bother doing anything personally, and I trust a good bike tuner with a load cell dyno far more than your twisted sperg brain that won't let you leave it alone.

Remember you can also re-map for cleaner emissions or for better fuel economy, but you can only have one attribute at a time, and mapping an engine for the best possible clean emissions is crippling it in any chance of it running really well and to its best potential.

[Easy-X]

Yeah but no but...

Indeed the voices in my head are yammering but personally I'm only interested in things that aren't a pointless waste of money and things that are interesting to do just for interest's sake.

Setting up a "home dyno" sounds like way too much effort obviously but it is annoying that it's only a sliver out of wack and yet there's nothing (practically) that can be done about it.

It also annoys me en principe that I have vehicle that in one aspect isn't mine as I'm subservient to a "closed shop" of ECU tuning. Wasteful and finicky as old carbs are at least they're yours to do with as you will...

I shouldn't be an idealist at my age
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Easy-X]

[Riejufixing]

[Easy-X]

As I understand it, the cat likes it hot (cue Ste gif!) but that comes at the expense of shortening the life of the rest of the engine

I would guess that "big name" manufacturers spend a bit more effort on their "emissions friendly" maps, VW even went just that little bit further for their customers

I don't suppose the Chinese spent quite as much time on the dyno with their copies creations.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[GettinBetter]

[WD Forte]

Just bunging a resistor in is a bit crude as this assumes a linear response and will just skew the map a bit (or a lot) with a static resistor and may not give positive results.
The sensors behaviour and effect will vary with temp, throttle setting and load so this a project worthy of interfacing an mcu to, rather than making a flasher relay.

I'd start by putting a scope, or at least a meter on it to study its behaviour and understanding that as best I could before making changes.
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bikers smell of wee

[stevo as b4]

But what about if the OP wanted to alter the open loop WOT high rpm and under load fueling or the ignition timing? Fudging the Lambda sensor output with resistors etc won't do a damn thing to change full throttle fueling.

[Easy-X]

Yes, I thought it might be more complicated than it sounded. I wouldn't bother on my 125 but has anybody taken a look at the "Open" ECU efforts?
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter