205cc Stroker GY6 Met-Ruck

Hi Travis! My name is Steve and I am a big fan of what you’re doing here. Thanks for adding me to the forum and I hope I can contribute some helpful feedback. I have a scooter which I have converted to EFI in the past but this system has proven to be unreliable and expensive to fix. I have been reading on your forum and like how important keeping the price reasonable but the product outstanding is to you. I would be really stoked to try out your nanoefi system on my bike one day.


Welcome Steve! :wave:

Out of curiosity, what EFI system did you use on your scoot previously?

And what kind of problems with reliability did you run into?

Absolutely! :100:

We’ll make it happen. :+1:

1 Like

I have been using the rolling wrench Denver EFI conversion kit. It’s basically a rebranded eBay just with a decent base tune written.
The kit has been alright but it’s always had some odd running issues. It would sometimes randomly cut out at a stoplight and then fire right back up, little glitchy things mainly. I’m the type of guy that’s always looking for a good mod for my vehicles and I still see a lot of potential on the table with the efi system I have. I also like working on friends’ bikes and it would be nice to know of a good fuel system I could recommend, especially with the versatility of it being able to go on any small engine and most or all motorcycle engines

Also here are some photos of the build so far

1 Like

I’ve been following Matt for a while. I’m not really familiar beyond some of his videos, but I’m wondering if the random cut-out is due to a drop in fuel pressure from the pump as crank speeds return to idle.

Or does it seem more like a loss of trigger sync?


Beautiful swap!

Believe it or not, I’m the guy behind the old BDX GY6-ruck swap harness from a bunch of years ago.

That thing was way more complicated than it really needed to be, but turned out to be good learning experience overall. NanoEFI will look very similar in apperance (same materials), but the internal wiring is kept as simple as possible. So it’s easier to both install and produce. Lesson learned! :sweat_smile:


Wow! That’s gonna look awesome man! So I just found out that unfortunately, my MAP sensor is malfunctioning on my current EFI system. I can see now why Matt scrambled to develop version 2.0 of this system as I was one of his original beta testers and still have the same hardware, and there are some major issues with this version:

  1. Injector pulse width tuning only affect operation after 4k rpm
  2. The throttle blip/‘power jet’ function is not tunable whatsoever by the user, so your options are to richen the idle so there’s always extra fuel to burn, or deal with occasionally inconsistent throttle response if you rip too hard and she chokes on all that air for a moment, or send the ecu back to Matt for him to retune in Denver
  3. Fit and finish a bit awkward, harness larger than needed, hand tuner is cumbersome both to use and to try to mount somewhere, and it also does not have a write to ecu function so the hand tuner must remain plugged in in line in order to keep adjustments you make
  4. His system should have had support for ignition timing as well. Without it, I could never get the motor to run properly without absolutely dumping hydrocarbons when revved up ( I have a Snap-on 5 gas analyzer which does o2, emissions, and ambient air analysis. I am happy to make good use of it tuning and providing feedback)

Overall, it was a pretty solid first attempt and Matt was good to deal with, but if I have to worry about the sensors going it doesn’t make financial sense to keep it up because that sensor alone is almost $100 and I’ve really only used the efi for one season so far. And I never saw the fuel savings due to lack of tunability.


Is that the combination MAP/IAT/TPS sensor unit?

Man, that’s a tough one. I’ve been careful along the way to stick with existing mass-produced sensors for use with NanoEFI. So you can get replacements or spares off the shelf from anywhere for just a few bucks. Amazon, or even a local motorsports shop if you need it right away.

Heck yeah! :boom:

IIRC, the TPS is separate but im pretty sure it handles MAP and IAT functions.

Awesome. That makes so much sense, yet most of the kits I’ve seen including the one I own are built around expensive, proprietary parts where if anything goes wrong you’re kinda SOL.

I think it has something to do with the hand tuner communicating with the ecu. I’ve noticed that a lot of times when I will go to make changes to fuel trim, it will go super lean for a second while the hand tuner makes the adjustment which is often where it will die but then once the hand tuner finishes thinking and displays the rpm reading again everything will be fine.