What is the silencer cover on my 2004 50hp 2-stroke ? k?

[Do55nzi67don]

I have a 2004 Yam. 50hp 2-stk outbd w/ tilt-trim.
The user manual mentions the motor top cowling ( no problem there) but it also mentions the silencer cover - now I don't know what that is.... can someone tell me what that is ??
ALSO.....
This motor is new to me.... trying to establish if the piece of metal running horizontal at the bottom leftish of the mounting plate is a sacrificial anode - it's about 5 inches long, 1.5 diameter, roughly cylindrical in shape, metallic like aluminum color.

[99yam40]

silencer is the plastic cover over the carbs
A pic would help on the other thing

[boscoe99]

Every part that is used on your motor, and which has a part number, is shown in the Yamaha parts catalog. Let the parts book be your friend.

[robert graham]

The silencer cover has several purposes: to help muffle the rather loud intake sounds as air enters the carbs, and the other very important function is as a fire suppressor from backfires through the carbs. Of course it would also help keep water/foreign objects from entering the carbs....so that's what it's there for!...

[Do55nzi67don]

Thanks, Senior members - all very helpful. All Q have been A. I didn't dig deep enough into the
right parts lists. Thanks again.

[rodbolt17]

2 strokes, by design cannot backfire through the carbs.
some have no air box.
not needed.
however some two strokes need the air restriction and without that airbox its incredibly noisy.

[robert graham]

2 strokes, by design cannot backfire through the carbs.
some have no air box.
not needed.
however some two strokes need the air restriction and without that airbox its incredibly noisy.

Well I learned something here...I always thought a "lean sneeze" was some type of backfire through the carbs and apt to pose a fire hazard without the air/silencer box....thanks, Rodbolt!....

[rodbolt17]

ok, lean sneeze.
any gasoline engine with an intake track can have a lean backfire.

however on most two strokes that utilize reed valves this wont allow flames to exit the intake.

as that piston is coming down it pressurizes the crankcase very similar to what it did going up.
its also what drives the fuel pump.

however if the air/fuel mix in the crankcase is overly lean then it explodes while the piston is coming down.

the reeds seal and the only thing that can happen is the pressure UNDER the piston tries to reverse the crankshaft rotation.

over the years I have seen sheared crank keys to snapped cranks cause the flywheel tries to keep rotating.

some engines, like the looper 90 degree jonny/rudes and some of the loop charged mercs simply wont run without the airbox and if attempted can burn a piston.

some little motors like some of the 35 and 25 jonnys and others don't have an airbox.

unlike a fourstroke like a Volvo or a mercruiser that without the flame arrestor they can and will blow a flame several feet into the air and can blow fuel out of the bowl vent to add to the fireball.

but that lean sneeze is actually an uncon*****ed explosion in the crankcase.