Friday, 20 June 2014

Up and Running

Bit of a delay between posts I'm afraid due to not getting to the bike to do further work.

The PLX SM-AFR controller and sensor arrived and got installed as soon as I got at the bike. It's a nice bit of kit and install was very simple! The way its set up is that you only end up installing the wires into the plug that you will use so in my case it was just the wideband analogue output and the 12V & GND wires go through a separate plug. 5 minute job to fit these three into the same connector as I had on the wiring loom and plug it in.

Compared to the LC-1 too there is no free air or heater calibration needed. Once the engine was started, the AFRs were reading nicely and consistent with what the LC-1 used to tell me before giving up. All good for a spin!

I spent about 2 hours riding, logging, adjusting and then repeating the process. Most of the testing was carried out in 1st & 2nd gear initially on a sloped road in order to get the highest variance of throttle position and RPM. To begin with the VE table was much too rich (better than being the other way around). Over the course of a few runs, some tweaking brought the AFRs across the range up to between 12.5:1 and 14.5:1. More refinement will be required to get the AFRs more consistent across the table. I am going to use TunerStudio's VE Analyse software to get the table to within 90-95% of where I want it to be and I will leave the final refinement to be done on the dyno at the same time as creating a 3D ignition map.

Unfortunately testing was cut short when I went to pump the rear tyre and noticed a damaged valve stem. Too dangerous to keep going until it could be fixed. I didn't get a video either because of that. After the tweaking though, the engine seemed nice and crisp, response was good and it pulled nicely through the revs. As mentioned, more refinement left but it's definitely better than expected at this early stage in the tuning process. 


  1. Congrats I just read the whole story... Impressive work.

    Everything should be pretty straight forward from now on,regarding AFR tuning

    Keep up the good work.

  2. Hi, I've been following your project since its inception!, I'm keen on converting my bike from Carburetor to EFI!, my bike is a 200cc single cylinder, triple spark plug engine!, good for 23.5bhp! Called Bajaj Pulsar 200NS, its a Sister bike to KTM Duke 200!, they share similar Engine components except the Engine head and Duke runs on single spark!, As Duke is EFI!, can I use the Injectors and Throttle body from duke on my bike?, I read Microsquirt only supports Dual Spark, not triple!, how do I go about that?. I'm from India!, I need a bit of help and guidance!

    1. Best advice I can give you is to read the manuals for the Microsquirt ECU. Then read them for the Megasquirt ECU as the Microsquirt is derived from the original. Then, if you decide to run MSExtra code (I would as it opens up more possibilities) read the MSExtra manuals. All these manuals are available online and there is more information than you will ever need on these ECUs.

      Also read every thread, website and blog you can find that details an EFI conversion. Read what issues people had and how they were fixed. I'm afraid that is the only way to understand what you need to do. No-one is going to be able to walk you through the whole thing. I did 6 months research on this project before I ever bought a part and it still ended up not very close to where I had originally planned.

      Best of luck with your conversion! :)