Beta 20 with Sea Prop 60 Saildrive
Last spring I installed a Beta Marine 20 (Kabota 722 engine) with a Sea Prop 60 saildrive unit in my 1978 Islander Bahama 30, replacing the well used Volvo MD7A. I did the installation myself with the main goal of reducing engine noise and vibration (hence the saildrive configuration). I went so far as to replace the muffler with a Centek Vernalift muffler along with a Centek Water Separator, usually used in a generator application. The engine compartment was totally isolated and insulated, again to reduce the noise. I now have just over 100 hrs on the Beta and the engine/saildrive unit is performing as expected. The noise of the smooth running three cylinder engine is so low at idle that I can't tell if the engine is running or not when I'm up at the bow. However, and there always seems to be a "however", the Sea Prop 60 saildrive unit makes more noise in gear at idle than the engine! There is a very clear "ticking" noise when the transmission is put in gear, a noise that disappears above 1500 rpm. The noise sounds like a baseball card in the spokes of a bike wheel. It is annoying!The Canadian distributor for Beta (who happens to be local) believes it to be gear lash when the transmission is under minimal load. I have contacted the distributor for the Technodrive Twin Disc Sea Prop 60 and they do not have an answer, claiming that the noise is "normal". Although not a "mechanic", I am somewhat mechanically inclined and suspect that this much noise out of a gear drive cannot be "normal". Gears should mesh silently, certainly not louder than a running diesel! Sea Prop does not provide a schematic of the internal parts of the saildrive unit and, without taking it apart, I am unable to determine the source of this noise. Has anyone had any experience this the Sea Prop unit? Is this a common noise, usually masked by the diesel? Although I am certainly satisfied by the overall unit, I am disappointed that the transmission is making more noise than the engine!
Last edited by bvermeer; 11-30-2012 at 02:18 PM.