[flightlead404]

Originally Posted by Horneck

I will change the sparks tomorrow and take the intercooler off a s well to check again for boat leaks. What is the best way to check for boost leaks on top of a visual check?
What are you guys thinking about the 6% C/O at idle. Maybe this goes ultra rich under boost and initiates the misfire?

6% co is a 12.25:1 AFR (assuming pump gas) roughly. That's probably a bit rich for a warm engine, but a bit lean for a fully cold engine. Where are you testing it and is the engine warm (oil temp 90c or higher)?

Spec book says the US adjusting value for %co is 0.6% - 0.2% which is in the low-mid 14's AFR. For me, that would be too lean.

The type 930/66 (Eu and Canada) specs are 1.5% to 2.5%.

All that said, idle mix is just that, idle mix. Once you're off idle, above about 1,500 rpm the mixture is set by the control pressure and that is set primarily by the WUR. If your idle is fine, and your control pressures cold, warm, and on boost are in spec, I seriously doubt that is the issue.