01scarab29

question for ALL. Seems most of the time when looking at dyno sheets for boats A/F ratio's are 12.1-12.5. when doesn't anyone like 13.5-14 ,,, just trying to understand

sutphen 30

lean is mean,,but in a boat it will melt down.

Bawana

Well for NA engines, around 12.8 will give the best dyno numbers.

ICDEDPPL

iTrader: (1)

Precision

Like he said. While 14.7 is stoch, best power can be anywhere from 11.7:1 to 12.8:1 depending on the motor.

Now, don't confuse widebands O2 readings on dyno sheets for what the dyno computes as AFR. I have seen them very as much as two points.

Bawana

WOW!!!!!!!!!!!!!! I thought I had some bad ones in the past.... LOL thats something else

Precision

That stainless steel top hung in there!

mike tkach

iTrader: (3)

i have a few that look a lot like that one!

SB

iTrader: (1)

Engine's are run at WOT on the dyno.

Therefore, all data you see is measured at WOT...including A/F ratio's.

Precision

Not on everyone's dyno. ;-) I make pulls at different throttle positions to verify that the tune up is right. I have seen a few different carbs come in with tuneups that have caused motors to melt down at cruise. They were right at WOT but 19:1 at partial.