The AFR meter also tells you the end result of your tuning.

The main problem is when you have 6 different people tuning the engine over the Internet . This is a simple 540 with a 871 blower. Theres no need to reinvet the wheel here. I probably spent a total of 10 minutes on the carbs for him, changing the mismatched setup that was in the carbs. The boat went from being a pig rich turd fouling plugs and struggling to see 70mph, to much better running and 78mph with a couple small changes. The boat will run fine with a couple more small changes, but it's much better then it was prior.

How do you know it's closed at idle without knowing the vacuum the engine is pulling???? We just went through this with mine... Had 4.5 power valves but it was still rich at idle... Put a vacuum gauge on it and the engine has 3.5" of vacuum at idle so we moved to a 2.5 power valve.....

These carbs are not boost referenced. They are not seeing manifold vacuum , they are seeing vacuum under the carb but above the blower.

You can put a vacuum gauge on it , but it has to be hooked to a vacuum port under the carb but on top of the blower.

What's your engine setup?

925hp Fast Forward Engines. 540ci with 420 blowers. Basically same set up he has.

Boost referenced power valves?

Yes my carbs are boost referenced.

Figured as much. But thanks for coming in! :)

just fyi,my quick fuel 1050 blower carbs [boost referenced] came with 4.5 power valves and my 1200 hp engines idle at 9 in of vacuum .

Dan,
I saw your boat a couple of weekends ago in Racine, I couldn't believe how nice it looked! Very sharp looking boat, but I was confused? I saw some reference to a 38' and also a 39', which is it? We were both docked in the "Red" only section!
Steve

I will let you get back to your regular programed schedule then! In the mean time I will be boating without fouling plugs!!