Instructions on how to replace risers and manifolds
 

Ok, so one of the things on my long list is to pull the risers. I think that I might have a leak because I saw some water staining on the outside. Is this as easy as it looks? Looks like you just remove the exhaust hose to the riser and then a few bolts to take the riser off. I have searched and can't find detailed instructions on how to do this. Should I pull the manifolds off at the same time or just the risers? The manifolds looks alot more difficult to do.

Re: Instructions on how to replace risers and manifolds
 

I did the risers recently when I installed my fresh water cooling system, and yep its that easy. 4 bolts and the clamp for the exhaust.

Re: Instructions on how to replace risers and manifolds
 

Very cool. How about the Manifolds? Are they just as easy? I am thinking that since this was a salt water boat since its birth, I should probably go ahead and do the manifolds as well. Do you know if they are just as easy?

Re: Instructions on how to replace risers and manifolds
 

Well, I think not. Although I agree completely with your desire to investigate them. When you remove the riser, you will be able to see the extent of the corrosion to a certain point even in the manifolds. I did not remove mine, they looked fine.

Since it was in the salt water, did they have a closed cooling system installed? or did the raw water cool the engine so all the system was exposed to the salt water? The closed system I just installed protects the manifolds so they are cooled by the closed system, and if yours is that way you may have little to no corrosion in the manifolds but some in the risers where the raw water gets discharged.

Some of my bolts were very difficult to remove, in fact I had to take the boat to a bolt extractor pro for two of them that would not cooperate.:mad:

Hope yours comes apart much easier.:wink_thumbup:

Re: Instructions on how to replace risers and manifolds
 

I did mine on th eold boat when I up graded the engine they and the manifolds were cracked and heard it was a common issue not sure though. But anyway I switched mine to aluminum as I never run in salt and saved alot of wieght as Zack said though if they have been constantly in salt check them out very carefully while your in there and soak those bolts for a couple days with a good penetrating oil as much as you can then if possible hit with an impact they all popped easy on mine. Good luck with it.

Re: Instructions on how to replace risers and manifolds
 

Well, I finally got around to pulling one of the risers. i guess the original owner didn't flush the engine after each use like she said! After seeing this, I am going to replace the risers and manifolds. Also, what is the valve that is in between the outdrive and the risers? it looks like some kind of backflow preventer. I know it is a bad picture, but it looks like one side of this "flapper valve" is completely corroded away. Is this correct?

Re: Instructions on how to replace risers and manifolds
 

Chris that is a shame but honestly it is what I FULLY expected when I first saw this boat come up for sale from the PO. I've always had my eye out for a 275 or 302 so of course I gave thought to it. The bottom line is this IMO. If someone is too lazy to spend 5 minutes after they use the boat to put covers back on it they certainly will not spend the hours of time for other maintenance issues. Its a shame you will have to go this deep on the boat but atleast you will know where the boat stands and good sweat equity after you complete your work on it. Good luck!

Re: Instructions on how to replace risers and manifolds
 

Yea, I knew that we would have to put some money into this boat. I bought this as a project boat and we only paid $12,000 for her, so I think we are still ok even if I got to replace the whole engine! My wife and I have had several boats, but we were blown away by the 275's floorplan. So hopefully I can fix this and get back out on the water!

Re: Instructions on how to replace risers and manifolds
 

Y eah slap a 502 in her and away you go;) no seriously sorry to see that hear alor of horror stories about salt water all the best on this project.

Re: Instructions on how to replace risers and manifolds
 

Yea, would love to put one of those aluminum shiny 502's in her, but don't have the money for that. We have to spend $1,000 for the manifolds and risers and another $1.000 for the diverters and solenoids for the Captains Call. Maybe in a couple of years though...

Re: Instructions on how to replace risers and manifolds
 

Or since it's a small block already in there slap in a 383 stroker for 400hp small block power. It will bolt right up.

Re: Instructions on how to replace risers and manifolds
 

Can you sell me one for $1,000? :wink_thumbup: Ha Ha just kidding. But if I change the motor, that will also change my diverters angle! hhmmm, so instead of dropping a grand into new manifolds and risers and then not being able to buy my exhaust diverters, I am now thinking about just replacing the engine. Damn, if I only had $5,000 right now!

Re: Instructions on how to replace risers and manifolds
 

Glad to hear your gonna do the captains call exhaust!!!!

Re: Instructions on how to replace risers and manifolds
 

Hmm I know of a guy with a boat with a 400 hp small block... oh yeah I sold it to him I think it only cost me about 3.5k to build if I remember correctly.

Re: Instructions on how to replace risers and manifolds
 

Hell yes! Actually, I will be just reinstalling the system. The original owner removed the diverters. But now that might have to wait because after removal of my risers, I see I have a few issues to fix first.

Re: Instructions on how to replace risers and manifolds
 

Damn you Darkcalling! Now you got me thinking about replacing my whole engine! I mean, I do have to drop $1,000 in her just for risers and manifolds and then however much that backflow preventer costs. Plus I do have a small oil leak somewhere. And I have seen those marine 383's online for $2,900 rebuilt. Guess my Bimini will have to wait. :wink_thumbup:

Re: Instructions on how to replace risers and manifolds
 

That's the way!!! I told the wife the it was cheaper for me to build my new one then find new heads got and early frost the one year mid sept. darn it ;) Told her I would just make the same one I ran in my last '70 Nova... oh did I mention it would lift the front tire on launch lol the boat just rocked too