I know how you can go faster :)

Those might be the stock temp sensors. The bung size you need is 18mm. Mercury does not use 02 sensors except for the 2009 motors and some late 2008 engines.

Dustin you dirty dog.....stop teasing us!!!
mike:p

Me too.. lol :D :D Jamie / Lakeside

Raeburn:

Check your fuel pressure settings with a calibrated fuel pressure gauge and make sure they are not higher than 50psi key on, engine off. You might also try turning down the fuel pressure just a couple of pounds to lets say 48 psi and try that briefly to see if most of the overfueling that you see occuring disappears. As I have posted before, some of this black soot is from our new wonderful gasoline blends and not unburned fuel. Look at the tail pipes of most new GM vehicles and touch with your finger inside when cool and you will see the same black soot and these vehicles run very lean on closed loop O2 systems.
As for fast boats, "Want a really fast boat, then purchase a fast boat hull to begin with, Want a big, mass produced pleasure type hull then be happy with mid 70 mile per hour speeds" You won't see any race teams using performance pleasure hulls and equipment for racing!

Best Regards,
Ray @ Raylar

I put the stock thermostat back in and also a fresh set of spark plugs. The motor's running around 170* now. I'm a little chicken to run 89 octane in it with those temps so I used Shell's 91. It ran great, a little lower speed than earlier in the year, but it's a lot hotter out now too. There's still soot on the transom, but it's definately not a bad as before (it washed right off when I got home). I can still smell unburnt fuel in the exhaust when idling through no-wake zones if the wind is blowing the right way.
Raylar, I will check the fuel pressure first chance I get. I know the previous owner increased the pressure after putting your 103 kit on - maybe he turned it up too high. All in all the engine is running great - not a single glitch other than the soot, so I don't want to mess with it too much. Hey Raylar, did you do any dyno tests with your 103 kit and the Whipple Stage 2 calibrations? If so did you see any Air/Fuel or ignition timing issues in the calibrations for your higher compression heads?

Thanks, Bruce

Don't keep running it for too long with it being so rich at idel. If you smell u burnt fuel at idel, thats more than a little rich. You will hurt the engine.

Whats weird is there's the fuel smell in the exhaust, yet the spark plugs look perfectly normal. Is the high energy of the coil near plug set-up keeping the plugs clean even though the motor is over rich?

I had a 23 foot Wellcraft sport hull that I put a 525cu big block in (it dyno'd 600 hp, 601 ft/lbs - though probably closer to 540hp at the prop). Thought it was going to just fly - best I could ever get was 70mph - not bad, but I was expecting more. It's like Raylar said, if you want a fast boat buy a fast hull. Sport boats don't have hulls designed for high speeds and need a ton of power to go fast. It was fun having something different though - I bet a lot of those '70+' boats were surprised to see a Crownline bowrider spanking them!

So you know the pain I'm feeling. :D 70 is about as fast as this boat needs to go. The plan is to yank this engine and put it in my next boat. The current flavor is a Hallett 255, but you can't find one east of AZ.

Sorry Dustin, you'll have to wait until the engine changes homes for the supercharger. As you already know...the forged internals weren't done by accident. :cool-smiley-011: