Yamaha Outboard - No Power

[fmastin]

When you replaced the fuel line, did you replace the bulb? When you pump the bulb in the fuel line, does it pump up to a firm bulb. I had a bulb with a minor air leak in it and it drove me crazy til we found it. Same symptoms; idle great but no power on full throttle. Even new bulbs can have this problem.

[s/v 'Faith']

You might have missed this, but the problem was found and repaired.... read back a few posts.

Originally Posted by fmastin

When you replaced the fuel line, did you replace the bulb? When you pump the bulb in the fuel line, does it pump up to a firm bulb. I had a bulb with a minor air leak in it and it drove me crazy til we found it. Same symptoms; idle great but no power on full throttle. Even new bulbs can have this problem.

[HueyHuey]

I know this is an old thread, but I too have been having these same problems with my port motor, just checked and it also was put back together the wrong way, I have pulled it off and cleaned it a dozen or so times each time putting it back on the same wrong way, then I read your post and checked it and compared it to the other motor and bingo, if only I had read this post earlier, thanks for the help!

[HueyHuey]

Originally Posted by Jmolan

My 9.9 Yamaha had a multiple trip to the mechanic's until we found the problem. There is a low oil pressure sensor that will cut it back to idle if it thinks the oil pressure is low. We found the sensor and cut the wires. Runs like a bad dog now. He also took out the thermostat. It was plugged and he thought it might be causing it to get warm and idling down on high heat. All is good now.

I tried everything, even exchanged every part possible with my starboard motor. Checked all my wires then found the oil ligt broken, checked the oil and it was really low, topped it up and it now runs, will keep an eye on it to see if there is a leak.

[GordMay]

Greetings and welcome aboard the CF, HueyHuey.

[Steamfitter]

I have a Yamaha 9.9 4 Stroke.I am having a similar problem, except when I put it into reverse it appears to have a lot more power and the engine seems to rev up to higher RPM's.
Any thoughts??