Replacing risers on 454

[lenoah]

Hi gang,

We have an '87 34' Tollycraft Sport Sedan. Great boat, we've had her for 12 years. Twin FW cooled 7.4 Crusaders with about 1000 hours run perfectly. I change risers every 5 years and they usually look like they could go another year or two but better safe than sorry. It is coming up on 5 years again.

My question is: which parts are critical to change? There is the water outlet ring, the 8" riser, the upper elbow and the lower elbow swivel. I don't remember 100% but it seems like the water outlet ring (also called exhaust spacer) and the lower elbow swivel are the least in need of replacement. While I understand the need to perform this scheduled maintenance item, I don't really need to spend $$ unnecessarily.

Any thoughts?

THANKS!!

 

[makomark]

I believe what you are calling the outlet ring only has coolant in it and should be just fine...everything from it back (atucally the blockoff plate back) should be replaced.

there are three things conspiring against the cast iron: salt water, exhaust gas, and high heat...the combination is very corrosive and cast iron will only endure in it for a fixed period of time...

 

[lenoah]

Thanks Mako, kind of what I was thinking. Ours has the upper elbow connected by hose to a lower "swivel elbow". That lower elbow never seems to be too bad either.