Old Boater,New Mechanic HELP!!

[louisianalogman]

There is a lack of boat motor mechanics in my area so I am trying to learn all I can about fixing them.We have to drive a while to get one worked on here & I want to remedy some of that.I've been boating for years with smaller,older engines & I have no clue as to some of the terms used on newer or bigger engines.Can anyone explain what the terms looper,crossflow,60 degree & 90 degree means.I appreciate all the knowledge I can steal.How can I tell if any of this apply to a motor?Thanks

 

[JB]

Re: Old Boater,New Mechanic HELP!!

Howdy Logman.

Welcome to iboats.

Loop scavenging and crossflow scavenging are alternate means of design, Logman. The "loopers" have flat top pistons, the crossflow have a flow deflector on top of the piston. Crossflow works better on small engines and for very low speed operation, loopers have better torque, make more power and use less fuel.

60 degree and 90 degree are the angles between banks in V type engines.

Tell us what engine you have (make and model number). You need a Service Manual for it (OEM).

 

[louisianalogman]

Re: Old Boater,New Mechanic HELP!!

Howdy Logman.

Welcome to iboats.

Loop scavenging and crossflow scavenging are alternate means of design, Logman. The "loopers" have flat top pistons, the crossflow have a flow deflector on top of the piston. Crossflow works better on small engines and for very low speed operation, loopers have better torque, make more power and use less fuel.

60 degree and 90 degree are the angles between banks in V type engines.

Tell us what engine you have (make and model number). You need a Service Manual for it (OEM).

Thanks JB! My brother has a 90 hp V4 Evinrude.I do not know the model # right off but it's in the 1980's year range.He also has a 1992 Yamaha 85 hp in need of a rebuild & I'm trying to rake up info & a broken part.Thanks for the info.