Yanmar smoking out rear

[marinesniper]

The prop is very dirty, so when in drive the boat moves very slowly even under full power...is this normal...?

Also alot of smoke and black stuff is comming out the back of the boat...could the gunked up prop cause the engine to work to hard and cause smoking and black crud...? if not what is the most likely cause...?

thank you,

[chris_gee]

Yep. Normal.

[marinesniper]

The black smoke is normal because the prop is heavily cruded...? The black smoke is only at high RPM...the engine starts very easy. One last thing, I notice that when in nuetral at high rpm there is not as much smoke...?

Is this all normal...?

thanks alot....!

[djodenda]

Yep. Normal. Clean the prop for happiness!

[SteveInMD]

Yes - you need to clean your bottom. All the extra carbon will accelerate the clogging of your exhaust system.

[Gary1]

Clean the prop and bottom. Running things with a really dirty prop will also tear up your transmission, particularly reverse gear.