1979 mercruiser 260 water in cylinders

[moparlewellen]

So this is kindof a long story. I got this boat and no one winterized it and hadnt ran in years. I found the block and manifolds were cracked. It has the old log manifolds on it. I got a new block and rebuilt it, replaced manifolds, and raw water pump, but not risers.

The first 15 hours or so it ran great. But had an issue with the bilge pump and water got up over the rear main. Got a bunch of water in the oil. I changed the oil a few times and ran it but me being an idiot I forgot to turn on the water. Never got over 220 but smoaked the new impellor. So I replaced it with a new one and ran it again but it was still getting hot and seamed to be hydrolocked later on.

I took it to the lake this weekend and it was hydrolocked slightly again and never got it started. Took it home and pulled the plugs to find water in 6 of 8 cylinders (chevy 350). My first thought is head gaskets but they are new. And after digging a little I found that I have water coming out of the water outlet at the riser when I remove the hose. I thought this was only a water outlet, could the riser be bad? Or is this correct?

 

[Scott Danforth]

you should have replaced the elbows

overheating didnt help anything

 

[moparlewellen]

Yeah I'm thinking that now. I was hoping to save the money but I think its just biting me now.

 

[moparlewellen]

Is the water outlet port on the risers at all connected internally to the cooling jackets for the manifold/riser? I shouldnt be getting water coming out of that going towrd the engine when disconnected and running should I?

 

[TurtleTamer]

That would depend on your plumbing setup, but bad risers are leaking water directly into the path of the exhaust, filling up those passages until spilling over into the exhaust ports of the engine and getting down into the cylinders.