2000 Yamaha 115 losing RPM / Power

Wamphyrr

Recruit
Joined
Jun 15, 2002
Messages
1
Just wanted some advice from the experts since the marina is taking weeks (2 now) to even look at the boat.<br /><br />Bought this boat (used) from marina, since then have put on about 10 running hours (115 HP 2 stroke Yamaha on a 19' Sea Pro CC).<br /><br />While out last time, the engine at full throttle (about 5500 RPMs) suddenly started kicking back to 3500 RPMS. <br /><br />Stopped, checked, no visible obstructions to the prop or entanglement.<br /><br />Over next hour (way in) it started to get worse (I started and stopped it to try it a few times), to the point where it will only get up to about 3500 RPMs...note the engine is not sounding like it is powering up to the full speed.<br /><br />No problems starting, idling, etc....just no get up and go. Fuel filter was just changed, oil changed, gas is from the same gas station that powers my car (87 octane).<br /><br />Any thoughts, or can I provide more info?<br /><br />Note that it also does this in reverse and in neutral (ie, wont RPM up).<br /><br />Boat has about 100 hrs total running on it.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 2000 Yamaha 115 losing RPM / Power

Howdy Wham. . .wam. . ., um, howdy.<br /><br />Sounds like you have lost a cylinder or two. More likely just one, if you can still get to 3500.<br /><br />Crank her up on the ears. Rubber gloves. disable each cylinder by shorting/pulling each plug wire.<br />If there is no change in rpm, you have found a dead one. Check for spark.<br /><br />If you find one with no spark, trade coils with another cylinder and see what happens.<br /><br />Let us know what you find. :)
 
Top