replacing risers in water

[jerryb1]

I have a V8 mercruiser old log style. It's been slowly rising in temperature to a point where it now runs at close to the red line level. I replaced the manifolds about 4 years ago but not the risers. It looks like the risers are above the water line. Can I change the risers and gaskets without pulling the boat out of the water?

Thanks

Maybe if it sinks, I'd be better off!!!!

 

[ENSIGN]

Re: replacing risers in water

Yes,Ive changed several at the pier,Drain the manifold first.

 

[Haut Medoc]

Re: replacing risers in water

I would drain the block & manifold to be safe....

 

[jerryb1]

Re: replacing risers in water

Thanks for the quick reply.
I guess the gaskets get damaged when you take them off, so I'll have to get new gasket sets. What's the best way to drain the manifolds?

 

[n2ostroker]

Re: replacing risers in water

some of the old log style manifolds didn'y have a petcock but they still had a pipe plug in the bottom of the manifold. The manifold should be cast with a fall towards the plug. Just unbolt the plug or open the petcock. Suck any water out with the bilge pump or use a wet-dry vac to get it all out of the boat.