need your thoughts

[hornets nest]

A friend of mine has a 77 Slickcraft with a merc I/0 351 Ford. The boots keep burning out that are attacked to the risers. The port side goes quicker than the starboard . We have redone the outdrive waterpump,housing,bushings and so on outdrive is getting water up to the engine . We were told to take the plates out of the risers that restrict the water flow witch seemed to make it burn the boot quicker. We have cleaned the risers thoroughly and have good water flow thru them. Main engine water pump and thermostat has been replaced . Has been an issue with the 351 Ford we have been told. But I know a lot of them are still out there running without this problem . The engine runs like a top. The flappers down at the t are there and functional. Cant believe there is a restriction in the exhaust to be able to run as strong as it does. Any ideas would be appreciated.

[2UNREEL]

You could have blockage in your exhaust manifold water jackets. Theses will block up with calcium or rust over time. You might pull the risers off the exhaust manifolds and inspect the water jackets for buildup. Atleast on my 350 the water combines with the exhaust at the riser to cool the exhaust. I put aftermaket risers in with a better water flow around the perimeter of the exhaust tube.

[sherman51]

You could have blockage in your exhaust manifold water jackets. Theses will block up with calcium or rust over time. You might pull the risers off the exhaust manifolds and inspect the water jackets for buildup. Atleast on my 350 the water combines with the exhaust at the riser to cool the exhaust. I put aftermaket risers in with a better water flow around the perimeter of the exhaust tube.

yea, what he said. i have heard of guys buying some type of acid and pouring in them and let them set for awhile then flush them out real good. i think i would just see if i could find a new set on ebay. but this does sound like your problem.

sherman

[medic]

I'd be willing to bet there's buildup in the water jackets, as Andy said. We had the same issue with our first big lake boat many, many moons ago and that was the problem. Good luck with your fix!

[N II Deep]

I have used "the works" toliet cleaner to remove rust (iron build up). I don't see why it wouldn't work on a manifold...

[hornets nest]

Thanks for the replies ! After thoughly cleaning the risers and putting another boot on it did it again on the way in yesterday after the 4 th trip. I guess our next move will be to pull the manifolds and soak with CLR as some have suggested and maybe extend the inside exhaust pipe down about 1-2" and see if that does it.