America's Definitive Marine Engine Magazine
The first thing Yamaha Motors did to improve its F9.9 and high-thrust T9.9 outboard motors was to make them easier to store. The simple solution was to add resting pads on the back of the motor allowing the motor to stand bolt upright on its back instead of laying on its side like a beached whale. If need be, though, the F9.9 and T9.9 outboard motors can also be laid to rest on their side. Not only does this scenario take up a smaller footprint, it also prevents the aggravation of scratches on the cowling. Another tweak, the tiller handle incorporates an improved folding mechanism that further slims the stored motor's profile by tucking it in tightly alongside the cowling.
Small outboards are by their very definition portable. Which means it ought to be easy to carry one from the trunk of the car to the boat, or to heft it over the gunnel of a boat. Those tasks are now easier thanks to a new carrying handle integrated into the steering bracket. And besides aiding storage, the previously mentioned folding tiller handle makes it easier to hang or dismount the outboard on its transom. I especially like the way the shift lever is mounted within easier reach on the tiller.
With that in mind also consider that the shortened tiller handle is undeniably more comfortable for most boaters, but not necessarily all boaters. For example, a solo boater in an inflatable boat often has to sit forward on the tubes to balance ballast (his own body). That guy may need to buy an aftermarket tiller extension, or, to craft one out of PVC tubing.
Remember in the beginning when we mentioned attractive new styling? We were talking about the new top cowling, a design (shape and graphics) that matches the larger engines in Yamaha's inventory. That means a T9.9 kicker motor matches the looks of main power.
Finally key features of these engines include either Shallow Water Drive System or Power Tilt for low-speed operation in shallow water. The F9.9 and T9.9 are quiet thanks to a single-latch sealed cowling, labyrinth exhaust and a water-sealed exhaust tube. The forward-mounted freshwater flushing device is easily accessible and the engine does not have to be running to use it. I like the way the carburetor's accelerator pump puts a sharp edge on acceleration.
Author Timothy Banse has published articles in Popular Mechanics, All Chevy, Pickup Van & 4-Wheel Drive, Mecanica Popular, Motor Boating, Yachting, Mar y Vela and many other magazines and newspapers from around the world. He writes about cars, trucks and tow vehicles and marine-engine technology.
|Yamaha Marine||F9.9 T9.9|
|Cylinder Block Configuration||InLine-2|
|Bore x Stroke
|2.48 x 2.29|
|Horsepower||9.9 @ 5500 rpm|
|Operating Range||5000-6000 rpm|
|Compression Ratio||9.46 to 1|
2.08 to 1
2.92 to 1
8.5 X 8.5
11.75 X 7