Overheating mechanic says head gasket

[Transtech]

Last weekend I went out on my 1989 skier and and about 45min into my trip my boat back fired and shut down with in 20 min there was about 5 inches of water in the engine compartment. Boat would not turn on but did crank over. Mechanic states that I have a bad head gasket. Last season at the end of the season I changed impeller water pump thermostat and oil change mechanic states that I have a hole in my baffles has this happened to any one before my temp gage was at around 160 mechanic states it might be off

[Woodski]

@Transtech  Plausible explanation from your mechanic.  Could also be a variety of things going on from your description.  If you don't have water flowing through system it is very easy and probably the exhaust heat will destroy the muffler (baffles), along with the head gasket.  When no water is circulating in the system the temp gauge will read air and not show a high reading.  You will want to trace back and find out where the water source to fill the bilge was.

[Transtech]

@woodski the mechanic is going to re glass the baffles and check for leaks I was thinking on replacing the baffles with stainless steel pipes what do you think 

 

 

[Woodski]

@Transtech:  A straight pipe system will be very loud, although it does sound great, but generally too loud for most.  You can get some pipe and then fit stainless silencers of various types if you don't want to fix the existing exhaust pipes.  The existing ones are simply made of fiberglass, you can cut them open near the baffles and repair if they are not burnt too badly.

Example of what is available:  http://www.cpperformance.com/c-472-slip-in-silencers.aspx

I made 4" diameter pipes with the slip in silencers and stainless 4" tips with added rubber flappers for my exhaust system.  

[Transtech]

i dont have flappers @woodski what is your take on that are they important 

[Woodski]

@Transtech:  They are important.  They do 2 things, most and critically important is to prevent backwash from running up the exhaust and flooding the combustion chamber which can cause hydrolock.  Second, they do an amazingly good job at noise suppression.  Many of the aftermarket tips come with some sort of flapper either rubber or metal.  As the saying goes, don't leave home without them.