Kick Start...

[BillClem]

The only real question that I have that has not been addressed in these texts on MicroSquirt is in regards to a kick start motorcycle (or I misunderstood...). I have a 1956 Harley Davidson that is a prime target for fuel injection but I do not desire to modify it to the extent of an electric start system (although my right knee would appreciate it). Can we configure MicroSquirt to start with a kick?

Thanks much,
Bill C.

[24c]

I think if you look in the Ignition section you might find something.

This is a recent topic
http://www.microsquirt.com/viewtopic.php?f=89&t=23351

PS Depends how big a kick you can give the old girl. ;)

[BillClem]

I don't believe it is even possible to kick a Harley hard enough to get 50 RPM's and even then, the tach signal would rise rapidly, then fall to zero. I understand the reasoning for the 50 RPM lower RPM limit but it certainly eliminates the possibility of utilizing MicroSquirt in this instance. Guess I'll stay with a carburetor.

Thanks,
Bill C.

[24c]

A French guy managed making an ignition box for an XT600 Yamaha, but Yamaha had two flywheel sensors on that bike, one worked on the kickstart the other for when it fired or was running.

The thing with the Harley, you could start it on the std ignition and drive the fuel from the coil signal or attempt an ignition only version at first and keep with the carbs. If you could start it on the ignition with your boot, then you could drive fuelling later.

[BillClem]

The old Harleys use a wasted spark point ignition system (that contributes to that exhaust sound) so, I'm wondering if the entire fuel/ignition could be configured as a two cycle engine? Fuel would be delivered against a closed intake valve on one stroke, then 45 degrees later onto the other intake port, then 360 degrees after the first delivery - then 45 degrees later again - alternating as the firing does...but 50 RPM's is still 50 RPM's on the crankshaft....

Just wonderment...

Bill C.

[BillClem]

I may still attempt this...as you say 24c; start it with a 'prime' squirt of fuel and with conventional ignition, then switch to port injection and MS ignition on that burst start - could work. Delay activation of a 'delay relay' with the first point closing to switch out/in the MS....would need a means of 'fuel prime'..... A false start would mean starting from scratch before each kick. The fuel pump would need to start with the ign switch to pressure the rail for priming. I believe the system is worth the attempt.....I have a throttle body with MAP, injectors, TPS and a removable (modifiable) manifold - and the desire.

I priced the parts to install an electric start on this bike - very close to $2000 - makes my knee quite hardy indeed!

Thanks,
Bill C.

[Andy_Stprbeck]

Maybe I'm not following this correctly, but it seams to me like a perfect application for a GM 8 pin HEI module with it's "cranking mode" that doesn't rely on the signal from megasquirt.

Also, 50rpms is way slow, less than one revolution per second. Seems like even kick starting a harley you'd be above that wouldn't you?

Could you pull some sort of a "twice as many teeth on the wheel" trickery to make it think it's turning double the rpms, so the Microsquirt thinks it's running sequential but is in fact running waste spark? Thus bringing you down to 25rpm minimum. Not sure how that would work out with the odd fire.

[Paul_H]

I have Microsquirt controlling both fuel and ignition on my Ducati 90 degree bevel V-twin, and although I elect to use the starter motor, there have been several occasions when I have kick started it. I find that when kick starting, ignition and RPM is not the problem rather controlling fuel intake during the process is a concern. It is a high compression motor and with too much fuel during starting it can become vicious which is not healthy for my leg. I think I have an operational problem with fuel pump control as it will run and deliver the priming pulse when uS is powered up but if the engine doesn't start on first attempt the pump will run again briefly and deliver further priming pulses without power cycling uS. This will continue to happen until the engine starts or becomes flooded. This is not a problem when using the starter motor as the engine always starts easily with the initial cranking. As you can imagine, this makes kick starting a very tentative process but I have to say that when the fuel is right it will start easily on the second kick.

[BillClem]

Andy,
50 RPMs for a kick is, as you say, above 50 RPMs but I'm concerned about whether it needs to be a sustained >50 RPMs to begin metering fuel (even if setting 2 or even 1 input pulses), as if a loaded map in the uS could sustain such a low speed....???? Will the engine actually recover from what would appear as a stalled (severely slow speed) condition? I guess this is where I must give this a try, see what happens and go from there.

Paul,
I'm understanding you to say that your pump shuts down when it attains rail pressure? And what about this 'priming pulse' that you describe? Is this a feature of this system that I missed again!? So did you find that your settings for cranking pulse and/or priming pulse would have been better of differently set if you intended to primarily start by kick?

Pretty amazing that a couple of responses to this topic and I'm ready to jump in once more and go after this installation....I'm easy!

Thanks much!
Bill C.

[24c]

I find that to kick start a bike successfully, you normally turn over the engine to a certain point...and give it a wallop with the foot thereafter. 50 rpm is the minimum apparently, but I can't crank mine that slow on a rig, and get a spark. However, I'm sure if your missing tooth is close to where you start your kick, you'll get enough inertia to trigger a spark event. Once spark is initiated and assuming you've got enough fuel, it'll fire and jobs done...it'll tickover.

PS Priming pulse,as I understand it, is your initial squirt of fuel,so it's a bit like priming a lawn mower, before you pull the cord!