I have a 1992 Honda 15, it runs fine out of the water, however, launch the boat, and when under power, misfires, runs at almost 0 rpm at full throttle. Now here is the strange part, if I remove the motor cover the motor runs great, in fact if the throttle is advaced when the cover is removed, look out as the boat instantly accelerates to the throttle setting. Drop the cover back into place and it almost shuts the engine off! Sounds simple, but, I removed the air baffle at the top of the cover, so no restriction, and same thing. Now, when the cover is lifted about 3 or so inches the motor begings to run normaly, I have used a metal object grounded to the motor and held it next to the spark plugs, nothing happens, no sparks, I have taken my hand and touched the wires, moved all of the wires and can not get any of these things to affect the problem. I have changed the spark plugs, rebuilt the carb, checked the carb air intake, choke is free and does not close, this is a truly strange problem! It must be related to load on the engine as it does not occur out of the water, I am sure it must be related to the ignition system, but, I can not see any problem with a plastic engine cover that is not touching any of the wires making this running problem occur! Has anyone ever seen this problem? I have the motor with a outboard mechanic and he put it into his tank and ran the motor, I got a phone call last night, he has never seen anything like this, ever....
