Swapping fuel injection for carbs

Back then I didn't know how to make it work either. Actually I had the concept, I just didn't know how to implement it. I went and saw several electronics gurus about making a plug-in box that would lengthen and shorten the injection pulse as required according to boost and/or throttle position, but they all just scratched their heads. They got around to it eventually of course, and called it a "Powercommander"

turpehar wrote:

I was wondering about the ignition system dying when you remove the airbox. What road can you point me down for the right way.

Can you get your hands on a wiring schematic?

My bike EFI knowledge is pretty limited, but then again, so is my auto EFI knowledge. It may be that there is a switch that changes state when engine vacuum (through the airbox) tells the computer to turn on the ignitors (sparkys) and maybe fuelpump / injectors.

No air flow sensed, no signal sent.

I have a shop manual. It has a full wiring diagram, but it's so small and convoluted you can't make much sense of it. I would like to find a write up of a swap including wiring mods. Thanks

ttt

The Mikuni BS34 are probably the easiest to find in decent shape for reasonable $. Make sure the diaphragms are good and that they haven't had the float bosses broken off. The GS1000 B34's will need a little work to convert to a side pull choke or you might use a thumb type actuator like on the old triumphs and keep the center pull choke. The BS34 were used up until 2002 or so and parts are easy to get.

The Mikuni VM28's seem to be floating around for pretty good prices too.

The only other carbs I have any experience with are the Mikuni 29mm. They have gotten expensive and parts are hard to find.

None of these will bolt on to a stock 81 head. So plan on some work there or in finding a head off a newer or older 'J' model.

If it were me, I'd fix the fuel injection. It's not bad when working right. The 82-84 fuel injection is different. No mass flow sensor. For someone trying to restore an 81, the fuel injection stuff is getting hard to find.

-Duck

I'm really getting sick of some ebay sellers. I have found what I thought to be candidates for the swap, and they will not answer my questions regarding the brand, model, and centerline measurments. One person told me that he didn't have any metric measuring tools, and that if I searched blah, blah, my answers would be found. Jeesh

turpehar wrote:

I'm really getting sick of some ebay sellers. I have found what I thought to be candidates for the swap, and they will not answer my questions regarding the brand, model, and centerline measurments. One person told me that he didn't have any metric measuring tools, and that if I searched blah, blah, my answers would be found. Jeesh

If the seller is not co-operative with fitment, you don't want his crap. If he is helpful, but holds feedback hostage, you don't want to deal with him. With ebay, patience pays, big time. If you're in a hurry, you'll get screwed.

My advice...if you're hot to ride and this is your only bike, see if you can work a swap with someone on KZR or buy a set of carbs from George... It's not a bargain if you waste half the riding seasom to save $100. Make sure your bike is otherwise sorted. Good compression, Ignition working, ...