low rpm's

[RAC]

took my H27 out on Kentucky Lake yesterday. while motoring in and out, i noticed that i could only reach about 2400 rpms with our Yanmar 1GM10. We bought the boat last August and we could run 3000-3100 rpms. We pulled the boat for the survey and the bottom was powerwashed in Aug and it had a new bottom paint last April. could bottom growth over the last six months cause this to slow down? or do i have some other problem? Thanks, Alan

 

[amcmahon]

Growth on the prop is most likely cause. Easy check is to clinb down into the water and check. Prop should be clean and smooth, if not use a plastic scraper and waterproof sandpaper. Cleans in a few minutes, ever in cold water!

 

[jcela]

Check both fuel filters. Low RPM's could be in indication that there is not enough fuel reaching your engine. I had same problem with my 29.5

 

[Rasselas36]

amcmahon&jcela have hhit the nail on the head. in both instances my Yanmar has done the same.