3.7l (170hp, "470") how long will they last?

[rinkerowner909]

Hi,<br />My second post here ever.<br />Bought a 1986 18ft Rinker with a 3.7l motor with 360hrs on it (I guess less than 20hrs/yr when you average it). Boat, motor and drive look like new and checked out fine when inspected by Marine Shop.<br />Question is, how many hours can you get out of these before a major rebuild is required? (I know it depends on use and maintenance). Suppose it was "normal use" not continually driven hard and that all yearly maintenance was done on the motor and drive. It is a Mercruiser Alpha 1 Gen 1 used in fresh water only.<br />I know there are some typical weak things with these motors. (ie charging system, water cooled voltage regulator) but does anyone know when these start to show up? (ie usually after 500hrs??)<br />Any thoughts or advice would be appreciated.

 

[tommays]

Re: 3.7l (170hp, "470") how long will they last?

there really is no answere to how long it will last but when it was checked out if a compression and leak down test were done these would give a good idea of the motors curent condition<br /><br />most motors die from neglict such as allowing an exaust manifold or riser to fail and cause water damage long before they really wear out<br /><br />the big weak point in the charging system has many aftermarget kits that allow a standard marine alt to be installed but if yours is working correctly there is nothing big to be gained by changeing now<br /><br />tommays

 

[Northern Eclipse]

Re: 3.7l (170hp, "470") how long will they last?

Tommays is dead on, If its good now, its up to you to keep is that way, neglect it or overheat it its done. My last boat had a 3.0 140hp Merc, I wore out a distributer, and timing gears, and popped a head gasket, sold the boat with over 1100hrs, motor was still strong It was well maintained and not abused on the same hand I'v seen 200-400 hr motors that were thrashed.

 

[rabidfish]

Re: 3.7l (170hp, "470") how long will they last?

The biggest problem was from water pump failures.<br /><br />This would "smoke" the regulator too. Keep the impeller fresh. Change it every 3 years at a minimum. If it hasn't been done, change the entire kit and the base also. This will give you a reference point to start from.<br /><br />Keep the coolant level up amd tune it up every other year, it should hold up for a while.

 

[Stings]

Re: 3.7l (170hp, "470") how long will they last?

i had to change my impeller and kit every 2 years. the charging system they put on it was a very bad idea. you will need to change it in the next 2 years, have it rebuilt or change over to a marine alt like tommays said. i have one sitting in this boat that needs that right now along with new seals on the water pump. im done with these engines. ill have the boat for sale soon i hope http://pg.photos.yahoo.com/ph/inraged@sbcglobal.net/my_photos

 

[MrBill]

Re: 3.7l (170hp, "470") how long will they last?

Rinker... you asked about the same question a month ago, although you might get more replies in this section. You'll get the most information though by doing a search on "470" or "3.7L".

 

[rinkerowner909]

Re: 3.7l (170hp, "470") how long will they last?

MrBill,<br />Not the same question really. I asked about the 3.7l motor generally.<br />I have gotten some good feedback and actually what I needed to know.<br />Thanks to those who chose to answer with useful info.<br />Appreciate your effort.

 

[achris]

Re: 3.7l (170hp, "470") how long will they last?

Mr Rinker, <br /><br />Something that nobody else has mentioned is that as well as keeping the seawater impeller in good order is to also have the heat exchanger cleaned out every 2-3 years. My neighbour has a 470 and I help him out alot on it. Few months ago he had a heating problem, would get a bit hot over about 3,000rpm. Took the heat exchanger and had it cleaned out professionally and he hasn't had a problem since. <br /><br />Basically what everybody else has said is good advise.... Check the exhaust elbow ('riser' for Bondo) every couple of years also.... Pull it off and check it thoroughly with a screwdriver. If you can punch a hole through it (on the inside), it needs replacing. <br /><br />Many people here aren't all that keen on these engines, but I think they're ok, properly maintained, and should give you years of fun and pleasure....<br /><br />Good luck and keep us informed.<br /><br />Chris............