Posted: Mon Aug 13, 2007 11:25 pm
Mike,
I have a 90TLDI on my 05M. In all honesty, when I started my search for a Mac, I would have been happy with a 10/15hp to get me out of the docks to where I could raise sail. The 50hp "appeal" did not sell me at that time. I had read all of the opinions presented here while I was looking and could understand each factions viewpoint. I still would see the kicker fulfilling my vision.
With that said, my used 05 Mac came with the 90 installed by the P.O. at a price I could not refuse. Even at first, I was unsure why I would want that much extra power, but a great deal is a great deal is a great deal.
He told me that he had the boat to 33 MPH, fully UNloaded, UNballasted, 1 person aboard, with a 13 pitch prop, 51-5200 rpm.
I have never been loaded that light. With my "standard" loading, and ballasted, the 13 pitch was way to high, resulting in only a 42-4300 rpm max out of a 52-5800 rpm factory number.
I was getting around 17-18 KNOTS with that prop, as I recall. I re-pitched to a 11 pitch and I hit the middle of the factory spec at 54-5500 rpm with a speed of 25 KNOTS "standard" loading, UNballasted. Adding ballast drops the speed to 19-20 KNOTS.
I seldom ever run WOT. I agree with others that the M really starts acting nice around 16-17 KNOTS and above. My usual long distance run (eg Catalina) is done at a sedate 45-4600rpm, UNballasted, "standard" loading plus towing a dinghy, at 16.5 KNOTS, 3 NM per gallon of gas.
So, in my experience, the 90 will do anything the 10/15 (or 50 ) would have done--- but not the other way around. To me, it's like a four barrel carb on your car. It's there if and when you ever need it.
I really like the fact that I can get to the "sweet spot" speed and not have the poor engine maxxed out all the time. To me, a 3/4 run 90 will be much easier on those poor pistons and bearings over the long haul than a maxxed out 50 running WOT all the time. At least, that's my logic.
My 90 TLDI weighs 315 lbs. The various 50's are in the 250-280 lbs range. There are kind folks who opine and inform me that the extra 35 to 60 lbs of deadweight will cause my transom to crack and fall off. Please expand on these theories, and never sit on the motor to enter and exit your dinghy. That combined weight must easily be in the 225 hp range, me thinks.
Would I do it again?
you bettcha.
I have a 90TLDI on my 05M. In all honesty, when I started my search for a Mac, I would have been happy with a 10/15hp to get me out of the docks to where I could raise sail. The 50hp "appeal" did not sell me at that time. I had read all of the opinions presented here while I was looking and could understand each factions viewpoint. I still would see the kicker fulfilling my vision.
With that said, my used 05 Mac came with the 90 installed by the P.O. at a price I could not refuse. Even at first, I was unsure why I would want that much extra power, but a great deal is a great deal is a great deal.
He told me that he had the boat to 33 MPH, fully UNloaded, UNballasted, 1 person aboard, with a 13 pitch prop, 51-5200 rpm.
I have never been loaded that light. With my "standard" loading, and ballasted, the 13 pitch was way to high, resulting in only a 42-4300 rpm max out of a 52-5800 rpm factory number.
I was getting around 17-18 KNOTS with that prop, as I recall. I re-pitched to a 11 pitch and I hit the middle of the factory spec at 54-5500 rpm with a speed of 25 KNOTS "standard" loading, UNballasted. Adding ballast drops the speed to 19-20 KNOTS.
I seldom ever run WOT. I agree with others that the M really starts acting nice around 16-17 KNOTS and above. My usual long distance run (eg Catalina) is done at a sedate 45-4600rpm, UNballasted, "standard" loading plus towing a dinghy, at 16.5 KNOTS, 3 NM per gallon of gas.
So, in my experience, the 90 will do anything the 10/15 (or 50 ) would have done--- but not the other way around. To me, it's like a four barrel carb on your car. It's there if and when you ever need it.
I really like the fact that I can get to the "sweet spot" speed and not have the poor engine maxxed out all the time. To me, a 3/4 run 90 will be much easier on those poor pistons and bearings over the long haul than a maxxed out 50 running WOT all the time. At least, that's my logic.
My 90 TLDI weighs 315 lbs. The various 50's are in the 250-280 lbs range. There are kind folks who opine and inform me that the extra 35 to 60 lbs of deadweight will cause my transom to crack and fall off. Please expand on these theories, and never sit on the motor to enter and exit your dinghy. That combined weight must easily be in the 225 hp range, me thinks.
Would I do it again?
you bettcha.
, 2 you can be the captian but that means the Admiral still over ranks you !!! 
but with my luck I'd be designated hull cleaner 
now is that a glass bottom boat I hear 
with my 50hp Honda four stroke, I can cruise at 9.5 Knt. Close to full throttle I can do 12Knt. Redline is 6000rpm. I don’t do that often.