Starboard Riser hose over heating

Speakrdude

Ensign
Joined
Feb 25, 2004
Messages
942
Hey All, I'm sure this has been asked before but, here goes,

I am having a overheating issue on my starboard side Exhaust riser hose.

The engine is a 70~84 model GM 5.7. (Volvo-Style) The Man's and risers are Barr replacements. The engine has a total of 122 hours on it. The question is, the original riser gaskets have 4 water passages and a "weep" hole on each end. The Riser/ man's have large water passages where the weep holes are at the gaskets. Are these restrictors still important or have they gone away with the newer riser/man's.

I believe I have a blocked passage or two in the riser causing the hose to overheat. Plenty of water flow to the man's and they look new inside. The risers have quite a bit of rust. Weird. Must be made of a different kind of iron.

I can make a riser gasket as I have in the past from Mr. Gasket exhaust gasket material.

Thanks,

Jim
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Starboard Riser hose over heating

Put the proper gaskets between the risers and manifolds. If your raw water pump is in good shape and the supply hoses are clear, and the risers and manifolds aren't plugged up, they will work fine.
NOTE: At idle and/or on muffs, one side will usually run warmer than the other. That is normal.
Get a temp gun and check them while running under load.
 

Speakrdude

Ensign
Joined
Feb 25, 2004
Messages
942
Re: Starboard Riser hose over heating

Turns out those are the original risers. Try soaking all day in Muratic acid, reinstalled, same problem. Order 2 new risers, 4 new gaskets.

These guys have great prices/service.

"http://marineengineparts.com/"
 
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