CONTINUOUSWAVE

jimh wrote:What is the elevation of the lake?

Sea level, this is on the Chesapeake and it’s tidal

Check the spark plug wires. The rubber boot on the plug wire may not be making good contact with the spark plug electrode. I owned some 1987 Yamaha three-cylinder engines. I had to use a nylon cable tie to increase tension of the rubber spark plug boot to hold it in place on the spark plug electrod...

So you have two things that clearly need fixing, those being the rough bottom paint and the motor mounting height. You are running a prop that others have had good luck with, so that's not the concern. It's hard for me to see that the mounting height and rough bottom could account for losing that a...

With the engine NOT running - Unplug the top spark plug boot. Start the engine. Run for a minute. Monitor sound.Shut down. Reinstall top plug boot. Remove middle boot. Start engine, Run for a minute. Monitor sound.Shut down. Reinstall middle plug boot. Remove bottom plug boot. Start engine, Run for...

Just for the record. Owners with this model and engine combination recommend these props. Engine mounted 2 holes up. 13" x 17" Yamaha Painted Stainless Steel *** 13-1/4" x 16" Yamaha Performance Series Three Blade 13-1/4" x 15" Turbo 1 4.25 ***OP reports this is his pr...

jimh wrote:As seen in Fig.1. the battery is on Port. Move the battery to Starboard. Propeller torque tends to make the boat lean to Port, and having the battery on Port increases that tendency.

There are two batteries. One on the port and one on the starboard side

How long have you had the boat? Has it always run this way, or is this a recent problem that has cropped up? I very much doubt you are running on two cylinders - you'd likely not be able to even get on a plane if that were the case. Is the bottom in decent shape, or rough and nasty? That can make a...

With the engine NOT running - Unplug the top spark plug boot. Start the engine. Run for a minute. Monitor sound.Shut down. Reinstall top plug boot. Remove middle boot. Start engine, Run for a minute. Monitor sound.Shut down. Reinstall middle plug boot. Remove bottom plug boot. Start engine, Run for...

I should add that the carbs were rebuilt 2 years ago and the motor preformed the exact same prior to rebuild of the carbs

Hi Phil, I have had two reputable mechanics sea trial the boat and both verified normal operation of the outboard. It sounds great at all RPM ranges. Is there anything I can do myself to test the operation of all 3 cylinders?

Hi all, I am reaching out for advice on my boat's performance. Here are the data: 1989 17 Montauk 24-gallons Fuel One Person- 250-lbs Two Batteries at Stern 2007 Yamaha 90 two-stroke with 230 Hours, Cylinder pressure 125, 122, 120-PSI Yamaha 17K propeller painted stainless Engine mounted in lowest p...