Blocked water passages on exhaust system.

[carlitos]

i have a 150TLRB Carburated V-Max with about 300 hours that i purchased new in 2003 and on which i just replaced the exhaust guide and related exhaust components due to corrosion issues.

This is a salt-water application engine which i flush for about 15 minuets on the hose and then finish-off on the muffs and Salt Away before the end of the day after I return home from fishing.

My concern is that upon disassembly I found that the water passages on the exhaust were hard packed and blocked with what appeared to be a whitish-calcium looking material.

I never have experienced a overheating problem on the engine itself and the temperature on the cylinders and heads are consistent with each other.

Would truly appreciate feedback and recommendations in order to keep the blocked water passage problem from reoccurring again.

[TownsendsFJR1300]

That's salt build up, especially in the very hot area's.

You run your engine (get it hot) to your fishing hole / beach, etc and turn it off. Water drains, the salt in the water cooks and adheres to the block. You start up, run again (numerous times in a day, weeks, years, etc).

Every time you turn it off, salt cooks and blocks the water passages.

You flush it when you get home but there's already salt hardened up on the block. The flushing helps, but doesn't stop the "build up cycle".

As long as you don't have any overheating yet, there's several procedures you can do to help get rid of the salt W/O pulling heads, etc.

Some interesting reading:

http://www.yamahaoutboardparts.com/f...g-th19434.html

http://www.yamahaoutboardparts.com/f...m-th23666.html

http://www.yamahaoutboardparts.com/f...h27868-p2.html (post #21 specifically)