YZF-R125 Power Commander Fuel Maps

I’m adding this page because of the number of people emailing me for 180cc fuel maps. Hopefully this helps and saves me some emailing 🙂 If a map worked for you or didnt, or you’ve managed to make a great map for your bike then let me know and I can add it here to help others out. info@northcust.co.uk 🙂

These are maps for a Power Commander V, but you can import them into the PCFC map editor too.

Please note I am NOT in any way an authority on this..I’ve just tested my way to where I’m at now. If that helps you, then great, if not maybe I can suggest soemthing but maybe not. All maps provided “as is” without any sort of warranty. The manuals for the PCV and PCFC are actually pretty helpful, have a read. Also there’s 125cc maps for various tunes available from the dynojet website:

ALSO NOTE: Really you need a map for YOUR bike. You can’t expect to just download a map from wherever for a bike with a similar-ish spec to yours, throw it on and then hope it will run perfectly. There’s so many variables which make each bike/motor a little different that there is no “one size fits all” map. Any maps you download from here or anywhere else (inc dynojet) ought to be seen only as a *starting point* which you then refine on a dyno, with an auto-tune or through A/B testing with street tuning.

Also the installation guide has some pretty helpful info – especially if you want to set up on-the-fly map switching (see under “accessory inputs”)

125cc Map (stock injector)

Back when I had the PCV fitted I also had the bike dyno tuned. That gave me a very nice baseline map which I further refined over the following year with riding/street tuning.


Some people who have tried the map said it was a bit rich for them so if that’s the case, maybe try making a variation with -5 or -10% added to each of the values.

2008 model, 125cc, K+N panel filter, Danmoto Carbon GP system, EGR delete, exhaust baffle tuning.

180cc Maps (stock injector)

So when I fitted the 180cc she ran on the old map but sounded horrible. Hard to describe how but then I just took the best map I had and added 40% to each of the values, which gave me a pretty decent starting point. It was still pretty horrendously rich in places but she wasn’t gonna melt at least and actually ran pretty well.


I also made maps with 50% but she seemed happiest on the 40% so I used that as my base moving forwards.

In the moments when my wideband sensor was working I was able to get some readings and refine that map further for my bike.

Please bear in mind my bike currently has some funky stuff going on with (suspected) timing chain stretch which is pushing the power band a bit lower than it should be. Hence this map being suited to *my* bike might not be so great on yours. You might need to richen the top end a bit or use the previous map.


If that’s too rich for you here’s the same map but -10% across the whole range:


and another with -15%.


2008 model, 180cc, K+N panel filter, Danmoto Carbon GP system, EGR delete, exhaust baffle tuning

autotune box (linked to the wideband O2 sensor), now installed and means we can build maps quite easily 🙂

180cc maps, 160cc/min injector (10 hole)

This is the first attempt at using the PCV and autotune to build a map more or less from scratch.

I’m working on a map for this currently. Got some good data today so will see what I can make of that and post results soon.

It does seem to run better at high RPM on the bigger injector so there might have been something to the theory that the standard injector was just maxed out at high rpm. It’s not magically fixed the powerband issue but it revs freely to the limiter now in all but top gear, which it did didn’t do before.

[coming soon]

[link to blog post /full writeup on this once published]

General thoughts:

The map below is an early one from when mine was on 125cc, but that’s not what’s of interest here. What’s interesting is that you have this diagonal band which thickens towards the middle which seems to suggest the area where the bike was running lean from the factory. My guess is that they make sure the fuelling is on point for flat out since that sells bikes (you can see not that much adjustment needed bottom right), but then the rest of the range is dialled back to make it pass emissions (e.g. at 70mph) or whatever. Just filling in those lean areas already made the bike a hell of a lot more fun to ride.

To some extent the “hollowness” of that band was probably made worse by me adding the k+n and exhaust system, so on a stock bike it might be less pronounced, but still.. it’s adding up to 20% extra fuel in there in places which is quite a bit over stock.

Street tuning without a wideband and without plug chops:

Anyone who knows better please feel free to let me know if I’ve missed soemthing. If I’ve misunderstood something then I want to know so I can understand it better.

For reference (as far as i’m aware) each cell is % fuel added per cycle. So if you had a grid of all zeros, that would be the same as (0% adjustment on) the stock map. Or if you had a map of all 10s, then that would be 10% over the stock map for the whole rev/throttle range.

By connecting up a simple switch (literally any open/close switch, see the “accessories inputs” section of the installation guide) you can take advantage of the map switching on the PCV and so if you had a stock bike you could have a map of all 0s (no change over stock) and all 10s (+10% fuel over stock) and whilst riding can switch between them and compare how the bike feels.

Perhaps it’s better overall..win. run it a while and see. Perhaps it’s better in the midrange but seems to be bogging down a bit under full power. No problem, adjust the map so that the higher rpm fields have smaller values or no adjsutment.

Moves of about 15% seemed to be quite noticable. Moves of 5% and 10% are there but you really need to be looking out for it. I tend to start with adding/removing 10% just in case i’m off further than I thought. I’d rather come back again and test with +/-15 once I know it doesn’t melt with +/-10.

Most of my interest tends to be what happens flat out since the midrange is pretty good already, so I’m mostly interested in the bottom 10 or so rows, and generally more the right hand side, all the way towards full ‘banzai’ which is 100% throttle at max rpm.

The point is that mapping doesn’t really have to be any more complex than adjusting a carb mixture, and a lot more precise & cotrollable. If you find your 10% map (’10’ in every field) doesn’t sound so happy up top but you love the low down, then maybe taper off as the values move down from whichever rpm the change seems to start.

Also: My PCV is fitted inthe tail, so I have a usb cable permanently fitted which comes down and sits curled up under the toolkit and means I don’t have to pop the pillion seat off to fiddle with the maps, just main seat off and there it is.

DON’T GO TOO LEAN – TOO LEAN = MELTY PISTONS. Keep an eye on your temperature. Will get hotter as it gets lean. Don’t have a temp gauge? I got you fam and here’s one way to fit it

I might have to do a more detailed video on this mapping thing actually, including the map switching. hmm.

In the mean time here’s a couple which touch on the map switching subject.

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YZF-R125 tuning, Stretching scooters, welding & fabrication, customising, custom parts.

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