Raise Risers?

[swansont]

I have a 1987 Sea Ray 210 Monaco with a 454 Mercruiser/Alpha 1. Summer before last I had it out with six or seven passengers on board. While filling tubes for towing, of course everyone was at the back of the boat, when I tried to start I was hydrolocked. (didn't know that at the time, thought it was the starter) Anyway, every since then I have been very paranoid about having too many people in the back of the boat and it happening again. I did replace the water shutters after that, but I don't trust them, and from what I've read, for good reasons. I am wondering if there is a kit or a way to raise the height of my exhaust risers so if people are at the back of the boat I don't have to worry anymore. Any ideas?

 

[tommays]

Re: Raise Risers?

<br /><br /><br />they make 3" and 6" kits its depends a lot on if you have ROOM to raise them and can reconnect the y-pipe<br /><br /><br />tommays

 

[swansont]

Re: Raise Risers?

I would have refabricate my engine cover but it would be possible. It might be be worth it to be able to use the back of the boat again, the way it was designed for.

 

[crazy charlie]

Re: Raise Risers?

There are many on this forum that say "dont bother to replace exhaust shutters,they are not necessary" You are proof that they are indeed necessary.4 things will usually cause what happened to you. 1-too many people in the stern of the boat 2 an abrupt pull back on the throttle to a stop. 3- no exhast shutters or worn shutters.4 a large passing wake to the stern of your boat.Avoid these things if you can and you will be able to trust your new shutters.Charlie

 

[swansont]

Re: Raise Risers?

Well, I had two of the four, too many people at the stern and the rubber was gone around the perimeter of the shutters. They probably would have kept a sudden backwash out but definitely weren't sealing.

 

[JSTSTRD]

Re: Raise Risers?

i had the same problem with my engine. Funny it is a 454 bravo. I wonder if the engine Weight has something to do with it. If you find the kits please let me know what you did and how involved it is. I lost an engine with hydrolock but managed to free this one. It is only 2 seasons old and would really like to get 6 or 7 years out of it at least.

 

[rodbolt]

Re: Raise Risers?

the shutters in your situation are a waste of time. while they MAY stop backwash they will never seal for an incorrect riser X dimension, whether its an installation or excess weight issue. I would try the riser extensions.

 

[Olds Eddie]

Re: Raise Risers?

I had the same thing happen to my boat. If it is within your budget, Imco marine makes stainless risers in taller versions that bolt up to the Merc manifolds. Since they are one piece you only have one riser gasket to worry about. They also claim a performance increase. I lost an exhaust flapper from one of my through-hulls and had no problems after putting their 6" risers on.

 

[TilliamWe]

Re: Raise Risers?

seems like these guys have you pointed in the right direction. On another note...<br /><br />How's that Alpha holding up behind that 454? You have a rare combination there. You can give advice to all those guys on here that want to put 300+ HP through an Aplha. Best of luck!

 

[swansont]

Re: Raise Risers?

Well.......I just replaced the lower unit, haven't had it back in the water yet. The previous owner had the unit rebuilt, there was only 20 hours or so on the rebuild when it shelled out on me. I'm not sure if it was a bad rebuild, or I damaged the unit, (I had the prop checked when I replaced the unit, it was fine)or how I treated it. The gears in the upper were in great shape. I have decided I will do something with the risers, if possible, I'll know more soon, plan to winterize next weekend. I 'll be able to check out clearances then. I also think the extra weight of the 454 is partially to blame, and I just don't trust the flappers and I don't want restrict my use of a 21' cuddy. Thanks for all the replies.

 

[Haut Medoc]

Re: Raise Risers?

Search in "Static Water Line", you will find plenty on the subject....JK