Merc 60 HP 2 Sroke 1999

[woodchopper]

Anyone know how durable these Mercs are? Can a little more Hp Be squeezed out of this engine? Timing? Carbs? Port Work? Iv'e been told adding a small amount of methyl hydrate to the fuel boosts Hp. Boat is a wide body Smokercraft 15Ft Can't crack 40mph. Like a little more top speed

 

[rabidfish]

Re: Merc 60 HP 2 Sroke 1999

Talk about WOT RPMs and the prop you're using...

 

[woodchopper]

Re: Merc 60 HP 2 Sroke 1999

props I have used 17 P 10 1/4 36 mph 4800 rpm 15 P 10 1/4 39 mph 5100 rpm Wide blade 14 P 10 3/8 38 mph 5100 rpm. Should 5500 rpm limit be reached? This is with only one person in boat. Thanx

 

[woodchopper]

Re: Merc 60 HP 2 Sroke 1999

Originally posted by woodchopper:<br /> Anyone know how durable these Mercs are? Can a little more Hp Be squeezed out of this engine? Timing? Carbs? Port Work? Iv'e been told adding a small amount of methyl hydrate to the fuel boosts Hp. Boat is a wide body Smokercraft 15Ft Can't crack 40mph. Like a little more top speed

 

[rabidfish]

Re: Merc 60 HP 2 Sroke 1999

With one person, and a fairly light load, I'd like to see you hit 5499.<br /><br />Try to get there with a good stainless steel 3 blade and you're probably going to see the best speed possible, without sacrificing something else.<br /><br />Advancing the timing will probably not gain you any more speed, and the ports are hard to do well because they're not exposed from the exhaust plate.

 

[Silvertip]

Re: Merc 60 HP 2 Sroke 1999

Engine height on the transom can also bring the RPM up. Check the antiventilation plate location in relation to the bottom of the boat. It should be even with the keel or very slightly above it for optimum performance.

 

[woodchopper]

Re: Merc 60 HP 2 Sroke 1999

Originally posted by Upinsmoke:<br /> Engine height on the transom can also bring the RPM up. Check the antiventilation plate location in relation to the bottom of the boat. It should be even with the keel or very slightly above it for optimum performance.

 

[woodchopper]

Re: Merc 60 HP 2 Sroke 1999

Thanx Rabidfish Is it true a choice of a stainless prop requires you to go down at least one in pitch due to the extra bite and less flexing at wot?

 

[woodchopper]

Re: Merc 60 HP 2 Sroke 1999

Thanx Upinsmoke I will check that height. I thought of raising it one bolt hole on the engine mounting plate. I suppose the drawbacks are more pull on the top of transom and the prop leaving water on turns and rough water conditions? This is a longshaft with power trim if it makes any difference

 

[astro1800]

Re: Merc 60 HP 2 Sroke 1999

you need to start out with the cavitation plate about 2 inches above the bottom of the boat, you probably will find that the best prop is going to be the 15p

 

[WillyBWright]

Re: Merc 60 HP 2 Sroke 1999

Once you get the prop closer to the surface, it's even more important to have a stainless. They dont ventilate quite as readily as an aluminum. You probably already know that 60Hp is the largest horsepower of that block, so there's no swapping parts for more Hp.<br /><br />You might check the full throttle timing to see if it is correct. Sometimes it is off a degree or two, usually retarded. You either need a test prop to do it, or you have to hang on for dear life as you flash the flywheel with somebody else driving. Full throttle on the trailer at the ramp doesn't count. It has to achieve full RPMs.<br /><br />Hp is achieved with RPMs. It is 60Hp at 5500, at 5100 it's closer to 55Hp. Don't take that to mean that it'll have 65 at 5800. It may, but you don't want things flying apart.