Hull Hugger

Morgan,
Since you are running hot at idle, check all the connections as well as strainer gaskets on the suction side of the RWP. There is no need to go to the high temp hose. Find the problem.

I took it up to speed, and I swear I couldn't tell any difference. I fully expected it to be louder, but my concern was that it was going to be too loud. As I said, some kind of instrument that measures sound in decibles may decern a difference, but my ears can't tell the difference. So, if anyone has to repair their hull hugger, and the baffle tube has broken away from the housing, I would advise cutting it out. That gives you one less thing to worry about coming loose, if nothing else. I'll say one more thing and I'm done with the topic: for those who say the baffle makes a difference, I'm quite sure it does or why would they bother with it? All I can think of is they had a goal of getting to or below a specific number, and they couldn't do it without the baffle. Thanks for the posts on here; it's nice to share information.

ffhd1clt wrote: ...but the point is, there is no noticeable difference in the sound without the baffle tube. I'm as surprised as anyone reading this...

Good to hear (or not hear ) that the repair worked out.

Well, I just now walked back in the house from reinstalling the hull hugger. The baffle tube was removed, then the muffler housing was repaired. It was a nice job, but I forgot to take a pic of it. He glassed in almost the entire bottom half on the input side, then he covered it with black gelcoat. I feel great about the repair, but was anxious about the sound. Once I got everything installed, I lowered the boat into the water (it's on a lift) and nothing leaked, so I started the engine with the floorboard and engine cover off. I could not even tell the difference from the muffler with the baffle tube. I bought this Nautique new in 1998, so I know what it sounds like, and to me, it sounds exactly the same. I don't doubt that some sort of decible meter could detect a difference, but the point is, there is no noticeable difference in the sound without the baffle tube. I'm as surprised as anyone reading this...

Well, I suppose while we're at it, I'll ask if anyone knows whether Correct Craft uses a special rubber compound for the rubber they install between the hull and the muffler. I was in the rubber business for a long time, so i probably over-think this one. My guess is they just use regular SBR rubber, but something like nitrile would stand up to the oil present in the bilge. Also, I guess a marine adhesive like 3M 5200 would be best to adhere the rubber to the hull. The rubber in mine had some sort of plastic backer on it. I guess that plastic was sticky at some point, but one thing is for sure, the rubber does not stay in place over the years.

Jones wrote: Scrawford wrote: Just make sure you use some carb cleaner to get rid of the grease/oil... Also, carb cleaner is petroleum based and probably the last thing you want to use (next to gasoline) when prepping for Fiberglass resin

Brad,
What do you feel is the problem using a solvent for prepping? The carb cleaner is just one of the chlorinated (making it non flammable) solvents. Typically acetone is used as a good prep.

Scrawford wrote: I find it hard to believe that the mfr would go through all the expense of the baffle to only cut noise level by 5%. Maybe at a certain RPM or certain load, but overall I would speculate closer to 20%. When you look at all the work companies go through to reduce mat'l costs, there is NO WAY Hull Hugger would add the baffle, tube, bracketing, and trouble if it only decreased dBs by 5%. I patched mine two years ago, including the baffle repair, and it is working like a charm. The baffle is no big deal in regard to repair. If you are already there then fixing the baffle at the same time takes all of about 10 min. extra. Just make sure you use some carb cleaner to get rid of the grease/oil...

Gee, I can't imagine a manufacturer ever over-engineering a proprietary product so they can gouge a consumer    I can only speak to my own experience but you are welcome to get a second opinion.

Also, carb cleaner is petroleum based and probably the last thing you want to use (next to gasoline) when prepping for Fiberglass resin

I find it hard to believe that the mfr would go through all the expense of the baffle to only cut noise level by 5%. Maybe at a certain RPM or certain load, but overall I would speculate closer to 20%. When you look at all the work companies go through to reduce mat'l costs, there is NO WAY Hull Hugger would add the baffle, tube, bracketing, and trouble if it only decreased dBs by 5%.

I patched mine two years ago, including the baffle repair, and it is working like a charm. The baffle is no big deal in regard to repair. If you are already there then fixing the baffle at the same time takes all of about 10 min. extra. Just make sure you use some carb cleaner to get rid of the grease/oil...

Thanks for your post. It's a bit of a load off, because I was afraid I was going to pay this guy to repair it, then install it and hate the noise it makes. Then I would be looking at getting a new one, on top of having paid to get the original one repaired. With the sound difference so minimal, you would think they would just manufacture them without the baffles, since they seem to break loose so often. I suppose they're trying to get every last decible they can get. I suppose you're right about the water, it makes sense that it would help deaden the noise. I'm not an engineer, but I can't understand why the exhaust can be above the waterline. I mean, the water that enters the exhaust isn't being used for cooling, so why can't they make the boats with the exhaust above the waterline? That way, you would have to worry about getting a small crack in the exhaust. Perhaps the reason is simply what you said...they need the water to make the boat quieter. Thanks again.

Have you confirmed that the noise level is about the same when using the hull hugger without the baffle, or was that just a guess? I know you said you were going to the "Y" configuration, but i thought i would ask if you happen to know how much difference the baffle makes. I took mine out today because it was cracked, and the guy who is repairing it for me is going to do it for much less $ if I decide to just remove the baffle instead of trying to repair it. Repairing the crack is pretty simple, but repairing the baffle is a pain, and there's no guarantee it won't come loose. I was just wondering how much difference it makes. I saw where one guy posted that the muffler without the baffle kind of "defeats the purpose," but as I have done some research, the vast majority of people think the baffle doesn't make that much difference. I don't think removing it defeats the purpose, because you still have a 2 inlet/1 outlet fiberglass muffler. The guy fixing mine was guessing it may be 10-15% louder, but he admitted that was just a guess. Thanks.

I know.., sorry , I screwed up.. you'll have to cut and paste into the browser. I'll see if I can fit it.

Here ya go... Edit-(links aren't working, give me a sec , or just cut and paste)....

Crap that blew out of the tailpipe. Probably remnants of the fiberglass downpipe that melted
http://phil.files.infostreet.com/Boat/P2140002.JPG

Some of the mud I dug out
http://phil.files.infostreet.com/Boat/P2160009.JPG

Header inlet with black mud still in there
http://phil.files.infostreet.com/Boat/P2160015.JPG

Everything I could dig out prior to flushing the header
http://phil.files.infostreet.com/Boat/P2160018.JPG

Again.., thanks for the support ! Tonight I just need to put the new thermostat in, mount the riser on the port side, attach hoses and I'm off to the lake.

Lastly., this morning I ran out to the dealer to pick up a spare impeller, riser gaskets, etc.. This dealer is where I initially took my boat after melting the downpipe. I got there when the doors opened, place was empty.., but low and behold found the GM sitting at his desk. Yes, that was his Merc S600 sitting in the parking lot.   So he helped ring up my order and while I was waiting I mentioned that his engine tech get an F in my book for my engine repair. He asked what happened and then blew off my comment with "we'll.., he's not PCM certified yet" So I called him out on it and told him that any tech that know anything about engines would know better then to return a boat to the customer without finding the root of the problem. He apologized and said he would "email the tech".   Unbelievable. I'm seriously thinking about creating a slam page online for this dealer so that Southern Ca knows that this company's tech can't troubleshoot a simple cooling issue. Once I got my hands in there I was able to find the issue.

If anyone is curious about who the dealer is PM me.., not sure if I want to post this as of yet.

Again..., thanks for all the help.

Phil.

Guys.., found the problem. Thanks for all the help.

The problem was a solid calcified mud ball at the inlet of the port heard. THere was a small hole allowing some water to pass through.., but not enough to keep the pipes cool. I dug that crap out with a screw driver and we are good to go :)

Will post pics in bit.

Phil
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Eric.., the dealer replaced the impeller, not sure about the swash plate. Probably not.

How hot.., if I run engine for about a minute, idle and a few revs to 3k rpms, with a garden hose hooked up I can touch the headers and risers and are pretty cool. However the rubber hose that connects the riser to the fiberglass down pipe on the port side is what's getting hot to the touch. After idle and a few revs I can put my hand on the fiberglass for only a second. However the starboard side remains cool at the down pipe.

Is there a way to back flush the header ? Since I have the riser off if I tape up the exhaust hole to keep water out, then take the drain plug out and inlet hose off.., shouldn't I be able to force any crap that's in there back out ?

Phil.
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Thanks Jones, Eric and Pete for all the help. This is really a great board and the willingness to help reminds me of some of the Euro car forums I belong to. But don't hold that against me ;)

The risers are off and there is no blockage.., although other say there could be blockage down in the header. So should I take the port header off and flip it upside down and flush it out ?

Will also take the fiberglass down pipe off and see if i can feel any blockage in the tube leading into the muffler.

Again.., thanks for the help and will report back if I find anything.

Phil