houstoncajun
Cadet
- Joined
- Apr 6, 2009
- Messages
- 27
I'm getting around 3800 RPM with a speed of about 25 MPH (22 - 25 depending on waves)
the boat is heavy 5500 LBs dry, 100 gal gas, 25 water, 9 waste and lots of beer and ice
its a 260 mercruiser 5.7 with an alpha 1 drive
I've changed distributor cap and rotor, plugs to ac delco, put good gas in it, timmed it a litte bit off though about 12 BTDC at around 800 to 1000 RPM (will fix that tomorrow) my compression checks as follows:
#1 125 #2 145
#3 140 #4 145
#5 125 #6 145
#7 150 #8 145
My specs are as follows from mercruiser:
WOT 4200-4600
Idle 650-700 @ 8 BTDC
1.50:1 overall drive gear ratio
In my manual:
The original prop Carver put on it was a 15 3/4" x 16, but there is a statement in there " 25 to 35% prop slip is common for a cruiser type boat operating at crusing speed"
"variations in load, operating conditions, enviornment, the individual engine and hull performance may necessitate the purchase and use of another prop"
Is there anyother way to find out if my engine is making the proper power without a dyno test? I dont want to change the prop if I have a engine problem instead
Any advise on where to go from here would be appreciated
the boat is heavy 5500 LBs dry, 100 gal gas, 25 water, 9 waste and lots of beer and ice
its a 260 mercruiser 5.7 with an alpha 1 drive
I've changed distributor cap and rotor, plugs to ac delco, put good gas in it, timmed it a litte bit off though about 12 BTDC at around 800 to 1000 RPM (will fix that tomorrow) my compression checks as follows:
#1 125 #2 145
#3 140 #4 145
#5 125 #6 145
#7 150 #8 145
My specs are as follows from mercruiser:
WOT 4200-4600
Idle 650-700 @ 8 BTDC
1.50:1 overall drive gear ratio
In my manual:
The original prop Carver put on it was a 15 3/4" x 16, but there is a statement in there " 25 to 35% prop slip is common for a cruiser type boat operating at crusing speed"
"variations in load, operating conditions, enviornment, the individual engine and hull performance may necessitate the purchase and use of another prop"
Is there anyother way to find out if my engine is making the proper power without a dyno test? I dont want to change the prop if I have a engine problem instead
Any advise on where to go from here would be appreciated