Stop in for a cup of coffee

Those systems all overlap to some degree. What I found (the hard way) was that when primary main jets were reduced sufficiently, the engine runs noticibly lean when cruising over 60 mph. The way I learned this was after a dyno session where between two runs with different PMJs the power looked very similar. So I drove home with the leaner jets, because, why not? Well you can guess what happened. The engine revved and died. It wasn't a good road to change jets on, but doing 55 mph in the right lane was pretty much keeping with the flow, so I just drove it home.

The "idle system" is a misleading name. Low speed system is better. Low load system is probably the most accurate if anyone wanted to rename it.


So then what systems are you using when cruising on a 35 or 45 mph road steady state??? Idle system, main system, or combination of both???