Volvo Penta D4 Diesel engines

Volvo Penta D4 Diesel engines
Engine Repower


  1. Poorly tuned engines have hard starting, lack of power, and use excessive amount of fuel. Engine tune-up require the inspection and or replacement of the spark plugs, wires, distributor cap, rotor, and points.
  2. Replacing the engine oil and filter will prolong the life of your engine by removing contaminates such as carbon, water, and metal destroying acids. Checking and replacing your stern drive or V drive fluid will prolong the life of your transmission. Water contamination is the most common cause of stern drive failure. We recommend changing your oil and filter at the end of your season during winterization.
  3. At least once a season your drive shaft should be tested. Your stern drives drive shaft is much easier to change at the first signs of wear rather than waiting till it blows apart breaking other components. The stern drive will have to be removed to replace the universal bearings. We recommend replacing the gimbal bearing while we have the drive apart. The gimbal bearing is between the engine and the universal joints to steddy the shaft.
  4. An overheating engine can be caused by a stuck or corroded thermostat, a worn out water pump impeller, plugged cooling hoses, or plugged or corroded exhaust manifold. If you have a closed or fresh water cooling system the antifreeze should be changed every two years. We recommend that if you have an open or raw water cooling system that you flush your engine with fresh water after every use. Even a fresh water system can benefit from a fresh water flush after every use.
  5. Saltwater corrosion can get into wire plug connections and cause wiring short circuits. This can cause problems as simple as lights not operating or your engine not cranking or starting.
  6. Water without the protection of antifreeze can freeze inside your engine and stern drive expanding and cracking manifolds, gearbox casings, engine heads and blocks.
  7. If your engine is worn out do to too many hours or no preventive maintenance it may need rebuilding but as engine parts become obsolete replacement is sometimes your only option. Another reason for repowering is older engines do not get as good of fuel economy as modern multiport fuel injected engines, Modern engines are far more reliable, easier starting, and produce more power with less weight.
  8. If your engine is in good shape but only needs a rebuild this can usually be accomplished within two weeks, Remember a boat engine is a high performance engine. It has been polished and ported to achieve maximum horsepower. The cam is built to give the best performance for a boat application. A crate engine used in an automobile will have far less horsepower. You will not be pleased with your boats performance. For example a Chevy 350 in a pick-up truck on average has around 180 Hp where as a Chevy 350 built for a boat will have upwards of 230 Hp. This doesn’t seem like a big difference but when your trying to pull your 200 lb buddy up on skis you’ll notice.
  9. Modern electronics make boating safer and more enjoyable. In most cases if you are upgrading your electronics the wire plug ends will not be compatible. New systems can be connected to look at your engine functions and boat performance to optimize performance and fuel economy.
  10. You invested a lot of money to purchase your boat. Protecting your boat’s bottom by inspecting the bottom paint once a year is good insurance that your investment retains it’s value. A buildup of barnacles or seaweed on the haul of your boat will slow it down and it will cost you more in fuel to push the boat through the water.
  11. You invested a lot of money to purchase your boat. Protecting your boat with zincs for salt water and magnesium for fresh water is cheap insurance that you won’t wear out your stern drive, propeller, or through hauls. Electrolysis will occur in all bodies of water. Your anode protects your expensive components from wear. The anode wears away differently depending on where your boat is moored. If your anode is half worn it should be replaced.
  12. You should look at your propeller at least once a month, check for bent or cracked blades. You should always carry a spare propeller, nut, and thrust washer. A floating propeller wrench should be in every boat. Even a slightly bent blade will cause vibration and wear on your stern drive. This will wear out your lower leg bearings and gears. In some cases you can achieve better boat performance by adjusting your propeller pitch. There is a simple sea trial test that will determine the correct pitch for your propeller and boat application.
  13. If your boat spends its life in the water a well maintained bilge pump with a fully charged battery is good insurance. Its as simple as keeping your bilge free of oil, dirt, dog hair, etc. The best preventive measure you can take is keep all water out of your bilge and keep it clean.
  14. All heating systems should be inspected once a year. All propane fittings should be checked for leaks. All hoses and pipes should be inspected for chafing.
  15. Most steering and throttle controls rely on wire cables running through plastic or metal sheaves. Larger boats use hydraulic pumps and rams for steering. Corrosion causes the cables to get stiff and hard to move. Leaks or lack of fluid cause hydraulic systems to not function or hesitate when you turn the wheel. Modern steering systems have fewer turns lock to lock. A new throttle control will shift smoother.
  16. Fuel, specifically gasoline, needs to be cared for. Most people are familiar with 87 octane it is known as regular at most gas stations. If you empty your tank every time you use your boat 87-octane fuel is fine to use. If you are like most boaters you will probably only use part of a tank. For every week that the fuel sits it will lose one octane. So if you start out with 87 octane one month later you will have 83 octane. Now your engine will have trouble starting because the gasoline has less BTU when it fires. If you start out with 91 octane your fuel would be at 87 octane after one month.
    So what happens after a month and you fill the tank? Well by adding more 87 octane to the 83 octane you’re now at around 85 octane. Your engine will start but not as easily as on 87 octane. This is one reason your engine should be kept well tuned, so you can optimize whatever octane fuels your using.
    If that doesn’t get you using a higher-octane fuel you should also know that the fuel refineries do not process regular fuel as closely as they do the higher grades. So by purchasing 87 octane you don’t know what you’re getting 85 or 89 octane who knows.
    The use of stabilizers will reduce the octane loss and protect your fuel from water and algae. When storing your boat for the winter you should either fill the tank with 91-octane fuel and the right amount of fuel stabilizer or drain the tank and start fresh in the spring. Leaving the tank less than full leaves room for condensation to accumulate and this promotes algae growth because the algae lives in the water and eats the fuel.
  17. More fuel talk. Gasoline left in your carburetor will turn to varnish after four months. When you have jets with orifices smaller then a human hair it doesn’t take much to clog them. This will cause symptoms such as hard starting, poor idling, and lack of power. Conditioning your fuel or draining your carburetor will go a long way to reduce varnish build up.
  18. Diesel fuel also needs to be cared for. Unlike gasoline it doesn’t lose octane but algae can attack it. If your tank is not full, condensation will accumulate and the algae will live in the water and eat the fuel. Fuel stabilizer will help protect your fuel from algae but keeping your tank full when you’re not using your boat is good insurance.