Nanni 3.30 engine fixes

As with many other boats I’ve owned, Red Line came with a few “surprises” in the engine department. Beyond the usual annual maintenance, I discovered some interesting issues left behind by the previous owner.

The Fuel Filter Air Screw

The first hint of trouble came during a routine filter change. The fuel filter air screw had been overtorqued to the point where the threads were completely stripped. Someone had really cranked on it! The fix from the previous owner was to cover it in a black rubberish goo.

I drilled out the damaged threads and re-tapped the housing to install a helicoil. This is a common issue I’ve encountered with all my previous engines, so I’m familiar fixing stuff after people with zero torque sense, but I must admit – I find it very satisfying to to install Helicoils.

Broken coolant tank bracket

The coolant expansion tank was hanging at a strange angle, held up by what looked like a spider web of cable ties. The metal bracket had failed due to metal fatigue and simply snapped off. Instead of fixing it properly, the previous owner chose to be happy with this solution. We are all different.

My first fix was to secure it with more strings – not pretty, but it worked while I figured out a permanent solution. As long as you use the same colour on the string as the coolant you are good – accoring to the engine manual. Eventually, after trying to rivet it (which failed both times), I had to weld the bracket back together. It’s been solid ever since, but that temporary string solution would probably have worked for many years to come.

Forgotten Exhaust Anode

During my first thorough inspection, I found the exhaust anode in a state that suggested it hadn’t been changed at all since the engine was new. It was almost completely sacrificed. I usually change stuff like this anually just to be on the safe side.

The Bilge Pump That Went Nowhere

One of the more puzzling discoveries was the engine compartment bilge pump. It was there, mounted in the right spot, but when I inserted the handle – nothing happened when I cranked it. When I traced the hose it simply ended in mid-air. Someone had installed the pump but never bothered connecting it to anything useful. I guess it was cut off for convenience during the Nanni engine install.

I replaced the pump with an overhauled pump and ran proper hoses so it could actually do its job – emptying water from the engine compartment when needed. Then I overhauled the old one with new rubber and sold it. Not exactly rocket science, but apparently all this was beyond whoever did the engine installation. I’m also thinking about adding an extra valve and a suction hose so the engine can pump out water too should that be needed.

The Routine Stuff

Between these discoveries, I kept up with the usual annual maintenance:

• Oil changes
• Filter changes
• Impeller replacement
• Anode replacement

Nothing exciting, but these are the things that keep the engine running reliably season after season. It is when you pamper your engine that you can discover potential future issues.

Looking Back

Buying a used boat means inheriting someone else’s maintenance heritage. Sometimes that works out fine, other times you discover creative solutions that need proper fixes.

The good news is that most of these issues are fixable with some patience and the right approach. And once you’ve sorted them out, you know exactly what’s been done and how it was done. Giving you piece of mind on the water.