I got out tonight for another test ride...
Swapped out my re-calibrated ECU for the stock Volvo one.
She idles right down to 600rpm. Has a bit of a lope so 700-800 would probably be better.
Anyway, installed a new plug for reading and went for a good hard run...
She ran strong at all rpm ranges and the test plug looked fine to me. Thought it would test lean but my co-pilot, a mechanic of 25+ years agreed, we were good to go...
I guess AZ Speed will need to go back to the drawing board on this one. The calibration they did was way rich.
Then we pulled out the GPS and let her rip...
Calm water, little wind, 1/2 tank, and 2 people, we hit 74mph on the speedo and 68.4mph GPS.
Engine rev'd about 4650rpm spinning a 3 blade 25p Houston Prop Accelerator.
The acceleration is awesome with the engine mods; the newly labbed prop showed vary strong as-well.
I guess if I want to hit 70, I will have to get out on the salt water solo and with an empty tank...

PAT,
SUPERBOAT- ROUGH WATER +FUMES + SOLO=70!
Oh yeah, and TRIM IT TO THE F'n MOON!
P.S. Pat, the 68.4, was that standing or sitting?hehe!

Got my ECU back from AZ Speed today.
Seems like they got it right this time.
My engine idles at 900 or so once it is warm, shift her into gear and it holds at 750rpm.
Tonight's test was a complete success.
Two people, 1/4 tank, 25p 3 blade, and the engine spinning just shy of 4800rpm, we saw 75-76mph on the speedo and 70.1gps.
Hey Bash, We were sitting and ducking behind the wind screen...

Solo you"ll be even faster. Break out that camera. Let's see some GPS shots.

I have to see if there is way for, my gps to hold the max speed like you show in your shot. Tough to hold the camera and drive.
Any ideas? Is there a special mode? My gps is like 6 years old...
I have though of buying a gps speedo, but boating budget is tapped out.

Pat, I got the Garmin 276C and it has a tattle tail(max speed).
Real nice unit.
and at $650+the chip, its a good deal compared to a GPS speedo @ $400+.

PAT
My E-TREX WAS $99. The GECKO is the newer version for slightly more. SPEED & MAX SPEED was my only concern.

Since this thread is speaking about speed I thought I would seek your advice. I finally got my boat back and she is running like a charm. The only nit picky thing I have is that the speedometer worked for the first few minutes and now it will climb slowly to near 50 and then it won't move from there. When I slow down it moves down very slowly. Any thoughts?

JMK
First step (& easiest). Take the rubber hose off the back of the speedo & blow. Something may be stuck in the line.

You hit a stick and there is a piece of wood stuck in the pickup.
Happens to me every Spring when there is so much crap floating from high water.
With your drive trimmed all the way up, look for a black plastic tube leading into your drive at the front of the cavitation plate. This tube brings water pressure to your speedo at the dash. There is a yellow barbed fitting that connects the tube to the drive. Rotate and pull up to remove it. If there is still pressure, you will get splashed in the face. Then run your hand down the front of the drive looking for a small hole about 2" above the level of the prop shaft. That small hole is the pickup. There is likely a piece of wood in it. I use a drill on low speed to get the wood out. Then blow through the hole to make sure it's clear. Reconnect the tube and your good to go.
JMK, we need to invest in gps speedos. Don't know about yours but my Merc. speedo is like 5-6mph off above 60 and this pito tube thing is a PIA...