MicroSquirt.com read only forum (Jan.15,2018)

Drove my project for the first time today, as we got just enough snow last night to ride. After a very short ride I stopped to check plugs and it seems like I'm getting more fuel in one cylinder. I'm also getting a stumble which seems like misfire, I had trouble with the coil pack last winter so when I get time tonight I will make sure that is not why I'm getting different plug readings. Its a twin cylinder 2 stroke with 2 throttle body injectors.

If I am getting different fuel amounts is it possible to get my injectors cleaned? or can I adjust each injector separately? Or have I overlooked something?

Thanks,

Seems like my Coil pack lead to the MAG side spark plug was a little loose. Had a similar problem with it last year, so I'm thinking that is why the plugs were reading differently. Wont know until we get some more snow to test.

Greg

This weekend I FINALLY got to go and ride/test/tune. Things are starting to go in the right direction. However, I still have some problems indicated by my friend towing me home.....

My system seems to cut out at higher RPM. Anything over 8000 rpm and it bogs. I've got 2 low-Z 55lb/hr injectors on a 2 cylinder set for 2 squirts per revolution. Thinking maybe the injectors are having trouble with 16,000+ opening closing events per minute. How can I verify this?

I'm running the tach signal off the OEM flywheel which is 2 equal length teeth. So I'm not sure I can switch them to alternating. thoughts?

Two things to check from a data log: are you maintaining sync when you go over 8000 rpm ? This would be indicated by the rpm going to 0 and back to rpm every time you go near 8000 rpm. Also by the trgger+/- column starting to count up or down whenever you go over 8000 rpom.

Second thing: look at the injector duty cycle column - is the duty cycle going over 80-90% ? If so then I would worry if the injectors are large enough to handle the fuel.

I'm in the process of changing the Injectors to HIGH Z 51 lb/hr, my calculated req. injectors is 29 lb/hr. I had much to high an electrical load with the LOW Z 55 lb/hr injectors setup + all the accessories. I'm also going to a proper fuel rail setup, and other changes. I'm putting the whole vehicle on a electrical diet. I haven't even had enough driving time to data log anything in the higher rpms(very paranoid about burning pistons). But once I get the snowmobile back on the snow I'm going to data log and find out exactly whats happening.