MILD THUNDER

iTrader: (3)

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.

mmb

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.....

MILD THUNDER

iTrader: (3)

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?

mmb

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

MILD THUNDER

iTrader: (3)

Boost referenced power valves?

mmb

Yes my carbs are boost referenced.

MILD THUNDER

iTrader: (3)

Figured as much. But thanks for coming in!

mike tkach

iTrader: (3)

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 .

509 SC

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

mmb

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