really gunna do it....
 

well im trading some pc repair work for all the stuff to convert a bike to fuel injection.... a guy i know races sprint cars and they convert everything to fuel injection. hes got hotrod polaris forwheelers and everything. ive been thinking about it for a while now but didnt really want to invest the money in it, but lucky for me his computer crashed and needs some serious work. it wont happen till riding seasons over with and i think i will just drop off the hawk for the winter and let him have it. i would like to get a set of pistons and cams and do it all at once but who knows.. moneys always an issue.

Sound like interesting work.
Keep us posted.

I guess my question would be, why? The thing works quite nicely with the carbs. Fuel economy sucks IMHO, but it seems to be the nature of the beast. Throttle response is great though; every bit as good (better even) than my TL-S was. Are you doing it for economy reasons?

That's the reason I am doing it on my Bandit, to get precise metering with the turbo system I am putting together (Was carbed the first version) but just as much, I am trying to get reasonable economy out of it... I can really only see that as the reason (better emissions I suppose too).

Just Curious. ;)

{edit, Not trying to discourage it, as a matter of fact, in a lot of ways it should me simpler to do than a 4 cyl. Just two intake runners with injectors in them and one good throttle body ought to do it. apply megasquirt and voila! Don't I make it sound easy? :crackup: :crackup: }

-Ross

actually itl be a dual throttle body set up.... i wanted to do a set of good FCR carbs on the hawk. i really like carbed bikes as if they are set up right they work really good... finding an adaptable set of fcr carbs is pricey though and this will esentially be free.

so to recap, the reason for doing this mod is not fuel economy, its not throttle response or power. its just that the guy owes me money and like all of us who have an expensive hobby, its easier to get parts laying around his shop from him then actuall money.

Cool! There's nothing wrong with a little bartering! And I agree, A nicely carbed bike is hard to beat. Injection can be really really sensitive on a bike, hence the reason so many manufacturers have computer controlled secondary butterflies to smooth everything out. Converting carbs seems like a smart way to go...its essentially what Yamaha did with there first gen fuel injection setup on the R1's; they even retained the cv vacuum slides. I am gonna be using a rack of those on my Bandit. I look forward to hearing more about yours in the next year!

-R

geh, i hat cv set ups. that was why i wanted FCR carbs and why im gunna go with this fuel injection system. to do away with the cv set up and also i should be able to run no airbox with the fuel injection and clean up the whole top side of the bike. if i pick up a pony cool, if it stays the same ang gets better gas mileage, cool. i spose the REAL reason im going this route is to get away from the CV stuff thas on the bike stock. and im using the fuel injection aproach as its cheeper then me moding FCR carbs to work.

Hmmm. In my experience, Flat slides work great for ultimate power, but make for less than desirable driveability. Had one on my bandit with the first Turbo setup, a big mikuni HSR42 and have ridden lots of bikes with Kehin FCR's as well.
My complaint is, if you snap the throttle wide open, you can lose intake vacuum/velocity and the bike stumbles hard. They try to compensate for it with an accelerator pump, but getting those 100% calibrated is a bit of a science too. However, if your ecu and injectors can respond to the extra demand, maybe it'll work great! I agree that it will be nice to be able to free up a little room under there by ditching the airbox. Good luck!

-R

In dealing with a single throttle body, 600cc fuel injection conversion, I found that the size of the throttle is very important. If you are too large on the throttle body, the difference between half throttle, nad full, can be almost indistinguishable. That makes transient throttle positioning pretty worthless, and full throttle overwhelms that engines ability to create vacuum. Usually TB size decreases from the size of carbs. 42mm carb---38mm for FI

for the ultimate kick in the butt, independent TB + injection is hard to beat, as soon as the ECU detect the TPS to be wacked open, it squirts his WOT map and from there all explosions are big and optimal. Our CV really sucks as far as throttle response in concerned, blast the throttle open and the slide still obstruct the carb throats, by the time it fully opened, the rider may fall asleep...
Kidding but the CV is by far the most commute friendly carb, witch is the most of our driving.
The ability to control fuel and spark in a single unit and in every operating condition is far superior to any carb. I feel that the spark is less than optimal for fuel economy and because Honda pays engine on their warranty and that we pay for the gas, they went with a very conservative timing map that begs to be ditched.

On a side note Megasquirt can't control spark on odd fire engines yet. Microsquirt will but it is not released yet...

these guys always go bigger on the throttle bodys. ive got a set of 46mm bodys that they can bore to 52mm if i want them too. and with the precision of the maping and running esentially an open airbox i can get all the air an fuel perfectly metered to it that i want.... they can build custom exhausts too but unless theyre comp dies again soon i am prolly on my own there. im not sure if the ecu they provide can controll the spark too or not. i havent looked at it real close yet. maybe this weekend i will sneek out there and do some more poking around.

these guys have been doing this stuff for years so i trust them. they race sprint cars and have a 125hp single cylender drag 4 wheeler.

niiice, well keep us updated on this, fuel only is a good start, odd fire engines like ours is difficult to get to fire 2 coils, most of the ECU are to be used with a distributor, one alternate way to do it, is to get megasquirt II extra spark. To configure it for a coil on plug wasted spark V8 and only use two consecutive outputs. That gives spark 90 degrees apart every crank turn or wait for Microsquirt to come out.
Just trowning that out there for those who want to know :D

ive actually glanced at that open source squirt software an thought it would be cool to mess with. these guys have a propriatery package all set up. its as near a bolt on as you can get. so unless i have lots of extra free time i will just let them use what they have already. maybe when im building a turbo kit or something i can get back into thmegasquirt stuff and worry about the timeing an everything else.

If you get free stuff, you sure should use it, BTW you did not mention what kind of ECU it is.

thas cuz i dont know... like i said i havent looked real close yet. and all i took with me was the throttle body's, it was getting late and i was out past curfew... (according to my wife anyways) ill try an sneek out this weekend and hash out a few more details.