DaleH
FOUNDER of Classic Parker Forum
My OB Rebuild - best boating $$ I ever spent! Kevin's recent post (1 a day?) reminded me to post this ...
I have put 9 hours so far on my OB rebuild, after I put a hole in a piston
(ID'd as a casting defect ...). I have to put 10 hours on her before I can set the final timing, stop the double-oiling (boy she smokes like Courtney Love at a metal concert :shock: when she starts!), and re-torque all the powerhead fasteners. I have survived the E10 fuel change so far too .
Best $$ I ever spent on a boat, this rebuild, the performance is A W E S O M E ! De-tuned (intentionally ******** ... the timing that is - not me ) to turn only 5200 RPMs, she'll still push my Pahkah (that's Boston for "Parker" by the way) to 40 MPH ... imagine the top end when I wind her up to 5700 RPMs after an appointment with a test wheel ! My new and current prop is a cupped performance offshore SST model 3-blade stainless 15"x17" by OMC. This beats by far the old stock OMC and Michigan 15x17 props I tried last year. Performance props DO make a difference, as do new pistons and rings I guess.
At 4000 RPMs and with the tide I'm getting 26 knots, 30 MPH, for better than 2.5 miles per gallon.
At 4800 RPMs I'm getting 32 knots, 37 MPH, for 2.0+ miles per gallon.
At 5200 RPMs I'm getting 35 knots, 40 MPH, for ~1.7 miles per gallon.
I'll take that ! I'll drop a couple MPH when going against a stiff tide, but note that the MPG doesn't drop as much ... or maybe it does, like a 10% drop off of each across the board ... I haven't run the math!
I will provide FULL specs and prop slip calculations after I re-time her and put some RPMs through the OMC test prop. This test is wild in case you've never witnessed one. You tie her down to the dock tight, replace the prop with a test wheel (which looks like a tug prop, i.e., a ringed or caged propeller) and then add a timing light and fire her up to at least 5K RPMs. The rooster tail exiting the test prop would douse any fire within 50' ... there's really not too much forward torque per se, but the spray created is indeed impressive :shock: !
I learned a lot through the process and I will say, when you punch the throttle and she jumps up on plane ... pure wood ... and I sure don't mean teak!
CP CONTEST:
Guess the final WOT speed in MPH, without going over (to the 1st decimal place, e.g., 43.3 or 45.1, etc.) and the winner gets a classic CP polo shirt in the size of their choice. Please enter only once and NO editing of your value is allowed. The decision of the CP Site Administrator is final and binding and ... yada yada ... yawn ... the rest has been deleted to protect the innocent.
I have put 9 hours so far on my OB rebuild, after I put a hole in a piston
(ID'd as a casting defect ...). I have to put 10 hours on her before I can set the final timing, stop the double-oiling (boy she smokes like Courtney Love at a metal concert :shock: when she starts!), and re-torque all the powerhead fasteners. I have survived the E10 fuel change so far too .Best $$ I ever spent on a boat, this rebuild, the performance is A W E S O M E ! De-tuned (intentionally ******** ... the timing that is - not me
) to turn only 5200 RPMs, she'll still push my Pahkah (that's Boston for "Parker" by the way) to 40 MPH ... imagine the top end when I wind her up to 5700 RPMs after an appointment with a test wheel ! My new and current prop is a cupped performance offshore SST model 3-blade stainless 15"x17" by OMC. This beats by far the old stock OMC and Michigan 15x17 props I tried last year. Performance props DO make a difference, as do new pistons and rings I guess.At 4000 RPMs and with the tide I'm getting 26 knots, 30 MPH, for better than 2.5 miles per gallon.
At 4800 RPMs I'm getting 32 knots, 37 MPH, for 2.0+ miles per gallon.
At 5200 RPMs I'm getting 35 knots, 40 MPH, for ~1.7 miles per gallon.
I'll take that
! I'll drop a couple MPH when going against a stiff tide, but note that the MPG doesn't drop as much ... or maybe it does, like a 10% drop off of each across the board ... I haven't run the math!I will provide FULL specs and prop slip calculations after I re-time her and put some RPMs through the OMC test prop. This test is wild in case you've never witnessed one. You tie her down to the dock tight, replace the prop with a test wheel (which looks like a tug prop, i.e., a ringed or caged propeller) and then add a timing light and fire her up to at least 5K RPMs. The rooster tail exiting the test prop would douse any fire within 50' ... there's really not too much forward torque per se, but the spray created is indeed impressive :shock: !
I learned a lot through the process and I will say, when you punch the throttle and she jumps up on plane ... pure wood ... and I sure don't mean teak!
CP CONTEST:
Guess the final WOT speed in MPH, without going over (to the 1st decimal place, e.g., 43.3 or 45.1, etc.) and the winner gets a classic CP polo shirt in the size of their choice. Please enter only once and NO editing of your value is allowed. The decision of the CP Site Administrator is final and binding and ... yada yada ... yawn ... the rest has been deleted to protect the innocent.
