INBOARD/STERN DRIVE

MANIFOLD TIPS

Manifolds can cause all sorts of grief to your Mercruiser, OMC, or Volvo if not maintained properly. I advise the installation of a "fresh water" cooling system on your outfit whyere available. With that 98% of cooling system problems can be avoided. A fresh water cooling system is set up similar to the radiator on your automobile. The engine coolant is passed thru a heat exchanger that is supplied outside raw water by the waterpump in your outdrive unit. The engine coolant uses the same antifreeze as your automobile so there is no problem with freezing and cracked components in colder climates. BUT - the RISERS are still raw water cooled as the raw water is dumped thru them to cool the exhaust. They must to be drained for winter. They can also become filled with corrosion scale and restrict the water flow through your motor. If your motor is running hot this is the FIRST place to check.

If the risers are not corroded thru you may clean them as follows. Obtain a gallon of Muriatic acid and a box of baking soda. get fill an adequate size container with enough water to dilute the acid to one quarter strength and immerse the riser in the solution.

WARNING!! Only do this OUTSIDE and in a well-ventilated area. Fumes are corrosive. This acid is very corrosive and WILL damage anything else it touches including YOU! Do this at your own risk. Leave the riser in the solution until it stops bubbling. You may add more acid as the process continues. Then neutralize the solution (and the riser) with the soda before you dispose of it.