Machine Shop Mods For Jet Ski Engine

As a personal watercraft owner, you might be unfamiliar with the many services machine shops offer. There is a common belief that a modified engine will lose reliability and that machine shop services are only for hard-core racers seeking a higher level of performance. However, this is not true! Machine shop services can offer tremendous advantages and improve the reliability and performance of your watercraft engine.

First, let's consider the basic engineering of a two-stroke engine, which is the power source for personal watercraft. The operation of the two-stroke engine comprises five events: intake, compression, ignition, power, and exhaust. All these events must occur in two strokes of the piston, or one revolution of the crankshaft. A compressed fuel charge is fired each time the piston reaches the top of the cylinder, and each downward stroke is a power stroke.

To improve the performance and reliability of a two-stroke engine, machine shops offer several services, including porting the cylinder, redesigning the combustion chambers and milling the cylinder head, cylinder boring and honing, exhaust manifold porting and machining, and carburetion modifications.

Porting is a science of custom-tailoring the intake, transfer, and exhaust tracks to suit the engine's needs. It is a tool for extracting the full potential from a production motor. Contrary to the myth that porting reduces the reliability of an engine, proper porting can actually add to an engine's reliability. A porter or portsmith uses precision tools to reshape and redefine port tunnels, which are tunnels in which an intake charge or an exhaust outlet is provided.

Porting benefits all motors by removing production discrepancies found within each engine. It can increase reliability and result in a smoother power delivery due to proper port chamfering and more efficient exhaust, intake, and transfer scavenging. Porting jobs vary at each and every shop, but the most common types are recreational (stage three) and race (stage five) porting. Recreational porting is highly recommended for the recreational rider and is generally compatible with pump gas. On the other hand, race porting is recommended for hard-core racers for maximum gains but is usually only compatible with race gas.

The effectiveness of porting depends greatly on the experience of the porter, so be sure to choose an experienced portsmith to work on your watercraft engine. Other factors that influence the effectiveness of porting include compression ratio, carburetion, exhaust system, impeller selection, and more.

In conclusion, machine shop services can significantly improve the reliability and performance of your personal watercraft engine. Don't hesitate to explore these services, and be sure to choose an experienced and knowledgeable portsmith to work on your watercraft engine.

Bobby Boop
​Impellers.com