"JohnDeere" wrote in message
...
I'm interested in changing the main on my utility boat to something
around 70hp, probably an oil-injected 2-stroke although I've not
completely ruled out 4-stroke. I've been wresting with using the 60hp
E-Tec or the 70hp Yamaha.

As you probably know, the Yamaha uses old-school carburetion.


The carburetors are not problematic unless the boat sits for more than a
month or so and varnish forms inside the passageways. Today's fuels gum up
fairly quickly unless you use a fuel stabilizer constantly.

If you are thinking of the E-TEC, the 3 cyl. 75hp is a sweetheart, and it's
very powerful for its size and super quiet. It tolerates ethanol fuels
better than most motors and is a big seller in Brazil where they run 22%
ethanol (depending on their goverment's whims). The 60 is a strong motor,
but it's 2 cylinder and not as smooth as a 3 banger.

About the rough running you mentioned, that was taken care of 2 years ago
with a software change to allow throttle position adjustment just like the
2007 models had. For 2008, they changed the injector plunger and ignition
system for even smoother drivability. Most of the earlier comments anyway
were due to not propping the motor correctly plus some had been operating
too cool, making them run rich.

Bill Grannis
service manager