Feasibility of EFI conversion 125cc motorcycle

[djsb]

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.

[dontz125]

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!

[guest]

...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

[djsb]

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

[24c]

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).

[monstermonkey]

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.