Topic: Fuel injection conversion (edit) fixed a few things

[750essess]

It is very roughly tuned at the moment too, still havent adjusted accel enrichments and such. There are improvements to be made that will make it rev better.

[Vtec-Sauce]

that is awesome!

[Pinhead]

Freekin awesome! I've always wanted to inject my 650 but it seemed too daunting a task (and expensive).

I'll be really interested in mileage once you get it up and running! Keep up the good work!!

Edit: Just curious, is it speed density or mass air??

[750essess]

I started with speed density, but after about 6000 rpms the map values are pegged. It is now running Apha-N, meaning it runs off a throttle position and rpm table. This is how most factory injections for bikes work. The microsquirt can blend from speed density to alpha-n, but I haven't figured out how to set it up yet. This would allow for smoother idle at low RPMs. (edit) I tried alha n blend and saw little improvement.

[MJL]

Are the new intake boots holding up so far?

[Shenanigans]

I noticed you don't have a kick start. Would this system not be able to be kick-started with fuel injection?

I say this because I read that Kawasaki is coming out with some dirtbike that is fuel injected  but has a kickstart. Is there some technical hardships with that?

Only because I think it would be damn cool to have a kicker bike with fuel injection...

[MJL]

I think I read either in this thread or another that he had to program the computer to read cranking speed at 200 rpm, could you reach that speed with a kicker?

[750essess]

Yes, the intakes are still holding together. Kick start should be possible after it is tuned properly. Anything thing below the cranking rpm setting is a "start" condition for the ECU above that it goes to "run" mode. It is a problem with dirt bike injection because they dont want a battery in the system, because of weight. The susuki and kawasaki dirt bikes use a capacitor in its place. First kick charges cap, next kick starts. Also after fixing my wiring mistakes,the charging system is holding 13v with motor idling at 1500 and lights on . This with a solid state Reg/Rec.

(edit) The kickstarter must be capable of at least 50 rpms and it doesnt hold voltage with the lights on while riding.

[mmtsquid]

How long before you have a complete parts list and start selling those intake boots? 

[cben750f0]

i second that!!!! 

you have done a brilliant job Mate, BTW is the bike idleing high?.... just wondering B/c the manual always say set to 900 rpm or so..lol, i have never managed to get mine to idle at that.

Love the way it sounds also... very clean, would this system take out the roughness of a real lumpy cam? i know that on some really performance car that the injection takes the rough idle out of a cammed engine?... just wondering.

NEway keep up the great works..

peace

[750essess]

I haven't got mine to idle that low either, it seems to like 1500-1600 anything lower and gets rough. It has a webcam 63b in it IRC. I strated this project with the intent of making kits, but the cost to have manifolds made out of rubber would cost about $10000 for the tooling and such. I dont think I could sell enough kits to make any money or even break even. Feel free to pm me if you are interested in doing this and I'll help best I can.

[Pinhead]

It seems to me that the rough idle below 1500rpm could be caused by weak ignition; charging voltage drops off below 1500.

I'm going to try to build a regulated DC-DC converter that will supply the coils between 16 and 18 volts with an input anywhere from 11 to 15. I posted some info in the MPG thread about it.

[MJL]

It seems to me that the rough idle below 1500rpm could be caused by weak ignition; charging voltage drops off below 1500.

Or a weak injector pulse.

[Pinhead]

But you notice that it's common for even the carb'd bikes to run rough below 1500. I have to set my '79 CB650's idle right at 1500rpm or it'll run like crap for the first few seconds pulling away from the light; the low voltage makes less spark energy and makes the engine act like it's leaning out. Once the RPM's get back up and voltage goes back to normal 13.5, everything works perfectly.

[750essess]

The injectors I'm running are on the large side, pulse width at idle is small (around 2ms). This is probably why it doesnt idle well below 1500. Also have 10.5:1 compression and lumpy cam, not helping things. The voltage holds at 13v so I dont think that is it. The dyna 2000 should provide good spark down to 10 v.
(edit) I tuned the voltage compensation in the ecu and added a vacuum resevior and can now idle down to 1000 rpm.

[bradweingartner]

The injectors I'm running are on the large side, pulse width at idle is small (around 2ms). This is probably why it doesnt idle well below 1500. Also have 10.5:1 compression and lumpy cam, not helping things. The voltage holds at 13v so I dont think that is it. The dyna 2000 should provide good spark down to 10 v.

Finding small enough fuel injectors for an older 500cc bike is real tough. I'd point directly to that. Do you know what cc those injectors flow? You might also want to play with high-res code on the 'squirt, might give you a little better control at those smaller pulsewidths. Though at 2ms you're just about out of room where it might improve.

Maybe a small cut in fuel pressure?

[750essess]

I'm running a cb750 bored to 836, but you are right about finding injectors for a 500cc. As near as I can tell the injectors are 280cc/min, it's hard to find specs on MC injectors. I really need to flow test them sometime. This is the first I've heard of "high Res Code" can you give me some more details. I too was thinking of lowering fuel pressure, the one that came on the TB's is no adjustable though. It is running at 55 PSI, I could stand to go to 45 or so, but would have to replace regulator.

[Ecosse]

Forgive me for being a Johnny come lately know it all arm chair engineer.

What about using OEM injectors? Surely there must be enough motorcycle FI applications on the market and if one can find who makes them for the bike manufacturer's it could help. 

BTW: Big kudos to you 750essess for undertaking a very logical modification. FI has been available for Muscle Cars for years. Whatever comes of this I wish you much success.

[MJL]

Go back and read the first post, he's using throttle bodies from a CBR600.

[Ecosse]

Go back and read the first post, he's using throttle bodies from a CBR600.

Oh yeah, I did start from the start but apparently my memory fades after five pages.

Thanks for the heads up.

[bradweingartner]

I'm running a cb750 bored to 836, but you are right about finding injectors for a 500cc. As near as I can tell the injectors are 280cc/min, it's hard to find specs on MC injectors. I really need to flow test them sometime. This is the first I've heard of "high Res Code" can you give me some more details. I too was thinking of lowering fuel pressure, the one that came on the TB's is no adjustable though. It is running at 55 PSI, I could stand to go to 45 or so, but would have to replace regulator.

Hi-Res code is a branch of both the normal B&G firmware and also of the MSnSExtra code. By giving up PWM injector control, the Processor has enough guts to give you an extra point of precision in the pulsewidths. I'm no programmer but from what I've seen it smooths some things out and can help with low-ms idle pulsewidths.

At 220cc/min, that's a lot of flow! Lots of cars come with 180cc-ish injectors which might suit you better. Some even drop to close to 100cc, but they are pretty scarce. I have some injectors from a Hyundai 1.5L in the mail, I think they are 180cc. Still trying to find some Ford Festiva injectors which are pretty much the smallest I've found easily at 120cc. Of course, most of these ratings are at a typical automotive 45-ish PSI. At 55psi that changes things.

What does the regulator on the bike look like? You may be able to find an automotive regulator that more or less drops in if it's the typical two bolt design.

[Pinhead]

From GoFastNews.com 34:1 AFR, on injectors:

ATM I am chasing DENSO C60 or DENSO UC 12 hole injectors as they are meant to be the best atomising fuel injectors on the market. Apparently the US Toyota Camry uses them but not avail aftermarket. If anyone can enlighten me on these injectors please do.

[750essess]

The microsquirt doesnt do PWM injector control so I think its already running the hi-res code.  Had some problems today...the fitting on the oil pressure sensor decided to crack, fixed that. Then the fuel pressure started dropping, thought it was low voltage hooked up charger ok for while then low again. Fuel was boiling in tank, need to find lower volume pump. The regulator is pretty standard for bikes but is much smaller than auto ones, may have to swap it to an auto style that doesnt mount on the rail, then I could adjust it. Could you measure some of the small car injectors if you have some so I can tell if they will fit in my fuel rail, would be appreciated. keihin, mikuni, walboro, delphi, and another I cant remeber right now make the injectors but info is hard to find for some reason. I would like to know how the OEMs can make a 600 idle on these injectors!

[bradweingartner]

Durrrr. For some reason I thought you were running a 550cc on Megasquirt. not a 836. I follow so many DIY EFi bike threads that I get them all sorts of confused.

The Microsquirt is running a completely different code from the branches I was discussing earlier. So disregard all of that drivel.

I'll gladly take come measurements as well as do a flowtest on some of the injectors I have around and have been saving for this project. I'll be home weekend of the 4th for a few days. Might build a manifold for my 550 while I'm home. Haven't decided yet if I'm going to try it on the mig or wait for the TIG... might actually just braze it.

In any case, I'll see if I can get you some hard numbers next weekend to chew on.

[750essess]

That be great, I'll get some measurements up of the keihin injectors soon too. There is a test mode in the microquirt that runs the injectors so you can measure the flow, need a graduated cylinder to though that I dont have. If I scrounge a cylinder I'll get flow rates as well. What kind of fuel pump do you plan on using? The in-tank pumps are perfect but i could find no way of installing one in the cb750 ss tank (not enough room).