Merc 140 Heat Riser Tube

[deanjoshua]

Hello All,

I'm replacing the exhaust manifold on my Mercruiser 140. In the process I noticed the heat riser tube that runs from the top of the manifold to the carb is rusted and it has broken off.

My dilemma... how the heck do I replace that. I asked the guys down at the local marina and they said us some brake line. OK!

Sounded pretty simple until I couldn't get the remaining line off of the manifold. Any ideas? Also, now I'm thinking, how do I re-attach the darn thing if I make one out of brake line?

Thanks again!

 

[cheburashka]

Re: Merc 140 Heat Riser Tube

Did it break flush with the manifold top, or is there a stub? On mine, I was able to silver-solder a sleeve onto the stub and put a piece of brake line on top of the stub. The tube really isn't very complex. If it did break off flush, you should be able to drill out the hole and slide a piece of brake line into the place where the old tube was. Mine was just open at the bottom of the manifold, but no exhaust gas circulates through it. It just conveys the surrounding heat from inside of the manifold.