MicroSquirt.com read only forum (Jan.15,2018)

Hi,
I'm new to this forum and EFI in general.
I am trying to figure out if a fuel only (initially) EFI conversion on my MZ RT125 motorcycle is feasible.
The bike uses a Mikuni VM24 carb and this feeds a 4 valve single cylinder dual OHC engine. The engine is rated at 11KW output @ 9000rpm.
The first thing I'm worried about is what is the simplest way I could convert the bike? I have a spare carburettor so maybe that could be converted? Or would I have to find a Injection throttle body off another motorcycle? Are there companies who manufacture custom ITB's for motorcycles.
I've had a read of the forum and the forum with successful motorcycle conversions but there aren't many 125cc bikes completed.
I've also registered on the megasquirt forum and had a bit of a read on there.
Can anyone point me to a source for further study?
Thanks.

David.

Hi, David.

Your project sounds entirely feasible, but you just have to pick your parts carefully (I've had fun shocking people with tales of 18k+ redlines and sub-msec idle times... )

Custom stuff is out there, but it's usually geared towards the big car engines, and $$$!!! I think your best bet for a TB & injector is off one of the new EFI scooters. Everything should be reasonably close.

Good luck!

...or depending where you are.
There are 125cc injected bikes Yamaha, Honda etc in UK and Europe. The Yamaha is a similar output to yours, and I have seen the throttle body/injectors on eBay, but you can also use a quarter of a more common 600cc bike, so you could adapt one throttle body off a 4 cylinder R6, CBR etc, and as you are not looking for huge horsepower, earlier throttle bodies will do...cheaper as well

Hi,
There is a Honda CBF125 injector body on Ebay at the moment. It's a Honda PGM-F1 unit. Would this unit be OK for the job.
Does anyone know any technical details about these units?
Thanks.

David.
London,UK

If it's the one I've seen just now, it should be good enough. Has a TPS, single cable with spring to close and looks like an injector nozzle in the pic, and if you're happy with the price it'll do. You just need a fuel pump/regulator next if the body doesn't have one (unlikely).

I started to type a response as I'm doing a very similar project myself, but it started looking like a thread-jack, so I've started my own thread over here: http://www.microsquirt.com/viewtopic.php?f=87&t=23658

Hopefully there may be some info in there that's usefull.

I think the MZ uses a Yamaha engine, MZ have done this a few times, mainly with the bigger bikes (Super Moto 660 is a Yamaha 5 valve) - maybe worth checking.