exhaust hose burn through on 89 force 125 L drive

[14rudy]

Gentelmen, I have a 1989 bayliner with a 125 L drive. Modle#125ld9b S# 1245. The exhaust hoses burn through often 10-15 hrsof use. The top first at the manifold. I have a manual and am very mechanical untill now. Repairs: New waterpump and pumps fine tones of volume /presure. removed thermastat completely. very little water flow out of housing when left open. new internal exaust gaskets.Inside (step) gaskets are in place.All updates seem to be done.the water outlet hose at the bottom of engine seems to pump all water into lower exhaust and not inside engine and out the top to cool the wet exhaust. Thanks for your time!

[MadmanShan]

water should come out of the thermo in large volumes,sounds like a blockage.

[Kiekhaeferscurse]

Hi Rudy, congratulations on keeping the L running, getting to be a rare bird.Mad is right, you have a restriction do you run in Salt water?Is the power head getting Hot( can you keep your hand on the exhaust jacket top & bottom.I'm gonna have to look at the old L drive manual for a Water flow diagram. I cant rememeber it well enough....let us know how your progressing

[DHPMARINE]

Found an old sevice bulletin about exhaust gaskets letting h2o into the lower cylinders.If this is happening,could the exhaust be blowing air into the water chamber,limiting water volume in the engine,or draining water out before circulating?Service bulletin specifies PerfectSeal Gasket Maker # 4 (Merc #92-34227-1).DHP

[14rudy]

Gentilman, only fresh water,gaskets are the updated type, engine is cold to touch and the over heat senser works. I do not understand how water flows from baseplate outlet to the inside of the engine. I thought of restricting the out flow pipe to see the results. when I put the new exhaust gaskets in, no sand,zebra mussles or odvious blockages could be found. the dealer also had no good clues. Please Keep me in mind. Thanks for your time.