LIFETIME OF MERC 2.5L 200HP, 1990

[CARLOS]

I bought a 29 feet boat like a Phoenix Fisherman stile with (2) 2.5L Merc engines... from 1990 engines...<br /><br />Ok, my questions are:<br /><br />1- Because this boat is really heavy, what kind of care can I do in order to improve the life time of this old 2.5L Mercs...<br />For your reference, the top speed is 28 knots at 5200rpm´s...really high engine speeds...so I´m afraid about poor durability of these engines because all the time I must to accelerate over 4200 rpms in order to achieve 22 knots...<br />I remember that my old 3.4L only was necessary 3400rpms to achieve 28knots!!!<br />2- I´ve heard that 2.5L achieve high rpm´s but they face a problem with connection rod bearings...I´ve seen some 2.5L with broken engine block because connection rod loose from crankshaft...! There is any problem with lubrication?<br />I´m thinking about to add oil also to the gasoline in order to improve lubrication...around 150 litters of gas per 1 liter of oil…<br />If you have any other recommendation or comment please let me know.<br />Many thanks for your attention.<br /><br />Muchos saludos desde Venezuela<br /><br />Carlos Schemel

 

[LubeDude]

Re: LIFETIME OF MERC 2.5L 200HP, 1990

Originally posted by CARLOS EDUARDO:<br /> For your reference, the top speed is 28 knots at 5200rpm´s...really high engine speeds...

Actually, you are lugging these engines, and I would drop at least one pitch if not two. This will get you to a closer optimum RPM limit of around 5,500-5,600. You will have a much better holeshot, and allow the engines to not be lugged which will make them live longer. I know it doesnt sound right to you that more RPM will make your engines last longer, but it is in fact true.<br /><br />As to the added oil, It wont hurt to add a little oil to the gas, but not too much. You may have difficulty with fouled plugs if you idle much while fishing.<br /><br />Keep them tuned up, and maintained well, and they will last a long time. Dont neglect the cooling system, new water pump, and thermostats every couple years.

 

[rodbolt]

Re: LIFETIME OF MERC 2.5L 200HP, 1990

hello<br /> what part of VE are you in? I make semi regular trips there and my fiance lives in Caracas, I may be moving to the Rio Chico area soon myself .