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

Hi guys,

This is my first post and I'm feeling really dumb for not being able to find this out myself. I've been searching the forums for a while with next to no help.

I've got my engine (95cc, two-stroke air-cooled single, RC airplane engine http://www.brisonrcengines.com/bri4u.htm) running, but at idle the RPM in TunerStudio is showing ~4000RPM. This seemed awefully high, so I threw a Tiny Tach around the spark plug wire and it read ~2000RPM which seemed much more believeable. I'm using a 36-1 wheel with a 12V hall sensor from DIYautotune to determine crank behavior.

Any ideas for what could be causing this? Please let me know what information I can provide that would help.

Also on a different topic, I would like to incorperate a CHT sensor to determine WUE because it's an aircooled engine. Has anyone done this or is there a better way? If so, do you have any tips on good, small sensors.

Thank you,

Shawn

PS: I've attached my .msq and .msl files of my most recent runs. I'm unsure as to whether I have the ignition settings correct. Is there another spot to specify "two-stroke" that I'm missing other than in "Fuel Set-Up --> Injection Control"? Another thing to not is the harsh misfires in the data-log where RPM drops to zero. This is actually visible in the toothed wheel and must be pretty aweful for the little engine

You have 2 problems- the rpm going to 0 is the more serious one and is most likely due to a vr sensor problem. Matt/ DIY can help with that.

The double rpm problem is due to a mis-configuration in the msq. The best option for your configuration is the Dual Spark option where you would set up as a single cam wheel. There is a lot of info in the manual on configuring 1 and 2 cylinder engines. I also included a writeup I did on this as an attachment that has the same info but is specifically for 1 and 2 cylinder engines.