Posted: July 13 2008 at 20:53 | IP Logged

Tony,

I'm a little confused. An I/O Mercruiser should have an alternator. The engine needs a battery to run and if it didnt have an alternator to charge the battery, it wouldnt run long. The alternator is what produces the current to charge the battery. It's really a generator that along with a voltage regulator produces around 14v to charge a 12v system.

Do you know anymore information on this?

Posted: July 14 2008 at 14:58 | IP Logged

Tony,

I think from your other post that you have the 4 cylinder mercruiser block.  The alternator is integral with the engine.  The stator and rotor is located behind the harmonic balancer.  The voltage regulator is located behind the exhaust manifold.  I have run marine batteries with no problem.

There are after market alternator kits to install an external alternator if yours fails.  The valtage regulator is expensive to repalce.  I think it was about $200 last time mine went.

This is not a typical marinzed automotive block.  You should get a shop manual.

Bob

Posted: July 14 2008 at 16:08 | IP Logged

Bob,

What years did they use this engine?

I’m interested in looking up some info on it.

Thanks

Mark

Posted: July 14 2008 at 16:38 | IP Logged

Mark,

I'm not sure of the exact years.  I think it was 1976-1989.  They had a change where they changed the materials in the exhuast manifold from iron to aluminum.  It is also known as 3.7 liter.  You may want to Google for history of the engine/block.

Bob