View Full Version : Decreased engine power

06-25-2011, 07:42 PM
I have a 140 HP in-board. I can get over 4000 RPM in idle, but when i put into drive I get very poor engine performance as it will only go to about 2800 RPM and the speed is very slow, maybe 20MPH. Any thoughts as to why when I put into drive the performance is poor.
I replaced plugs this year.
Thanks for any suggestions:):)