Injector Gaskets, Where Are You? You just finished installing reconditioned injectors on a HPDI VZ225TLR. You were letting the engine idle while checking fuel pressure and noticed a sound coming from the engine. It sounds like a compression leak near the cylinder heads. You don’t see any indication it is the head gaskets and don’t […]
Quick Tip: Removing HPDI Fuel Injectors
Removing HPDI fuel injectors from the cylinder heads can be a struggle, particularly in saltwater applications. Corrosion can build up between the injector and the pocket in the cylinder head. To block corrosion build-up and ease future removal, apply a light coat of Yamaha WR#2 waterproof grease (pn 90790-74046-00) to the metal injector body when […]
Checking Cooling Water Pressure
When troubleshooting a cooling system issue or optimizing motor jack plate height, one of the first things to do is check cooling water pressure. Ideally, all boats would have a water pressure gauge installed, but we all know that’s not reality. Unfortunately, even installing a water pressure gauge temporarily if the boat doesn’t have one […]
Quick Tip: Hex Driver
There are a few places on our motors where hex drive fasteners are used, typically on upper casing aprons and water intake screens. A thread sealant is applied to the apron fasteners to prevent salt and mineral build up from making the screws impossible to remove. While minimizing the effects of salt, the sealant can […]
DIY – Winterizing Your Four-Cylinder Outboard
Yamaha offers a popular line of four-cylinder four-stroke outboards that are used in a wide range of single and twin installation applications, in both fresh and saltwater, all over the world. From pontoons to center consoles, bass boats to work skiffs and even water taxis, they are great performers and real workhorses. The most popular […]
Identifying Fuel Filter Locations
Fuel delivery problems have been around since the first internal combustion engine was introduced to mankind. Changing fuel formulations and the complexity of modern outboard motors, plus the amount of use (or, more correctly, the lack of use) by the typical consumer have increased the need to be very thorough when servicing a fuel system. […]
Four Stroke Break In
Motor break-in? Now there’s a loaded question. Ask a group of boaters how to break in a new four-stroke motor and you’ll probably get at least as many different theories as there are people in the group: Boater #1 – Yep, just tie it up to the dock, shift it into gear and let it […]
Cylinder Head Bolt Removal
Before you torque the bolts you typically have had to remove them first. Cylinder head bolts can be difficult to remove, and it seems they get even tighter with use. Plus, the bolts are recessed in a pocket, making it difficult to keep the T55 Torx® driver aligned with the bolt while applying the pressure […]
Trim And Tilt Removal On XTO Offshore Models
The power trim and tilt unit (also called the PTT and PT&T) is an important mechanism that allows the motor to angle up or down. The correct trim angle helps the boat achieve the proper attitude (i.e., the relationship between the bow and the stern) and is responsible for the smoothness of the ride. It […]
PTT Relay
The Service manual provides the correct procedure for testing the Power Trim & Tilt (PTT) relay, but the procedure can be a little vague. In this article we will provide more detail about operation and testing. Relays are an electromechanical device commonly used to allow a circuit with a small amount of current flow to […]