Need some help with this Vtwin....please!!!

[old guy]

Here is an explanation that Grippo gave me when I first started messing with this thing.

In your setup you need 2 coils because of the odd angle between cylinders, meaning you can't fire them simultaneously as in normal wasted spark. That being the case you must have 4 separate coil charging/ firing events per 720 deg cycle, so skip teeth must be 12, rather than the normal 24 teeth for pure (1 coil) wasted spark. What determines rpm is no. cyclinders, but also the particular dual spark option, 2 or 4 stroke and, in the case of 2 cylinder, the odd angle is also a factor. If you have 2 cyl, odd angle NOT equal to 0 and skip teeth = 12, your rpm should come out correct for a 2 coil setup. If that is the only problem, the rpm can be rescaled to come out right by changing the scale factor in the ini file, but it shouldn't need to be.

I also recall that I had a problem with the rpm's reading wrong. What it was that when I specified 2 in the number of cylinder and burned it to the ecu it was not changing the number. Eventually for some reason it started working right and the rpm's were OK.

[old guy]

Try this and see what happens. Make sure you check the Ignition output as I don't know what you are using for coils and how you are driving them. Also check the dwell setting to suit what coils you are using.
If this doesn't work I may have to drag out my test stand and see what we can work out.

[tech3sandcars]

I will give the msq a try, really really appreciate it. It'll take me a bit to rewire the coils back in since I had put the stock cdi back in to get in running. I am using LS2 coils with the logic level drivers mod, everything worked good, I could make sparks jump about 1" when I was cranking with the plugs outside the motor. Thats a good explanation by Grippo, works for me.

[tryskriel]

Same thing here with my Harley engine
I did change the skip teeth to half my trigger wheel tooth to run wasted spark and it spark coil B at same than coil A so don't seem to work in my case.

[old guy]

Hope things work out for you. I also usedLS2 coils when I was doing my testing. The msq. I posted was your msq with the ignition settings changed.Like I said before if it doesn't work I will drag out my test stand and get something working. It is a lot easier to do it on a stand than thrashing your engine trying to get the settings right. It's been about 2 years since I did that project and I could only find one msq that I used so I hope all the settings are right.
Just out of curiosity; what kind of Kawasaki engine are you working on. I would assume it is an atv by your screen name.

tryskriel

If you post your msq or your ignition setting we could probably help you. There is no reason this should not work on a Harley, the same as any other v twin.

[tech3sandcars]

Yes its a Kawasaki UTV engine in a side by side set up for desert racing. Its a pretty wicked motor, the same motor kawasaki uses in many of their quads as well. I will try to take a snapshot of it and post. Sounds like "tryskriel" is having similiar issues with his harley, let us know what you find if he posts his msq.

Thanks again.

[tryskriel]

Just read my post tfor msq and more information

[ngcontrol]

I have been testing a 90 degree Kawasaki engine with LS coils over the last couple weeks,. Tried using cam sensor with starter ring gear (93 teeth) which worked pretty well, but had some synch problems over 3000rpm. Switched to a 36-1crank wheel wasted spark setup using 36 skip teeth and rpm reads 1/2 of actual. However the wasted spark setup will often back fire through intake when trying to start and if it starts backfiring it will never start. Eventually after a few start attempts it will start right up and run very well for hours on end. I think the engine has a 50/50 chance of synching on the right cylinder with 36 skip teeth. I think you guys are right, my skip teeth should be 18.

Bottom line though, Microsquirt combined with the LS coils on a 90 degree vtwin can work very well.

[eestrine]

We are running a Honda CX500 80 degree twin. I made some interesting discoveries this week. It has a 18 tooth flywheel with 1 missing tooth.

Here are the settings that made the spark come out where we wanted it;
Teeth 18
Missing teeth 1
Skip teeth 18
delay teeth 7
offset #1 -115 degrees
offset #2 80 degrees.

Our wheel looks like yours, missing tooth, then 'TDC#2, then TDC #1
I did a lot of experimenting to get to these settings. Tried 9 for skip teeth, RPM went from 500 to 1000 ??? TDC #1 is 7 teeth from missing tooth. When I tried 8 for delay teeth, RPM went to 250.0. Also entry for offset #2 is difference between TDC #1 and #2. Found that offset #2 must be positive. Any value more negative that -30 and there is no spark on #2 cylinder. These are what I call SUFs, special undocumented features.

So we ended up wit the timing at 10 degrees BTDC for both cylinders. Cranking RPM is 250.0 which seems correct, not sure.
Then we had fuel problems, but thats another story.
Elliott

[eestrine]

I forgot to mention in the previous message how we determined the -115 degrees for the offset. WE counted the degrees from the T1 tach tooth to the TDC #1 spot on the flywheel. It turned out to be a bit past the 7 th tooth. We started with -140 degrees and reduced the in 10 degree increments until the timing light showed at the spot we marked on the flywheel where we wanted to fire.

Good luck. Let me know how it works.

Elliott