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edwinfuqua
08-24-2006, 10:25 PM
On my '85 PS190 I have in the last 6 weeks had to replace the rubber exhaust hose at the manifold twice and the second time I noticed extreme blistering on the exit rubber so I replaced it too. I know I destroyed the impeller the first time and it got hot maybe for a minute. This ruptured the manifold hose, it leaked and it made the engine starve for oxygen - ran great with the hood up, bad when the hood down.

The next time the impeller belt slipped at about 4K RPMs for a few seconds this caused the manifold hose to show problems and it caused an exhaust leak again.

Simply, it seems if you loose water through the exhaust even for a few seconds you're going to ruin your rubber exhaust. I saw a post about bad performance in another old thread where the guy was checking everything except exhaust leak.

I've replaced every hose in the system. Using two clamps on all and hope I don't have this problem again. That second time, it didn’t help when I broke my circulator pump pulley either. We rigged that back together and limped to the ramp on ‘total discharge’ at least the impeller was working.

Any thoughts?

JimN
08-24-2006, 10:47 PM
Make sure the oil cooler isn't clogged. There's no reason it should heat up that fast if the raw water flow is good. Going WOT does change things, though.

edwinfuqua
08-24-2006, 11:00 PM
Jim I just put a new Trans oil cooler in this year and when I replaced all the hoses last week we looked for any opstruction by flowing water through the paths and looking. What's WOT? I never saw the block temp go over 180. I try to keep its max at 165. But it goes between 120-165 back and forth as the thermostat opens and closes.

JimN
08-24-2006, 11:13 PM
WOT is Wide Open Throttle and obviously, when you're turning high RPMs, more cooling water is needed to keep the hoses from melting when they're in contact with the hot exhaust gasses.

edwinfuqua
08-24-2006, 11:16 PM
Got 'ya. I know that the impeller develops a lot of pressure above 1500 RPMs and so it should. But loosing the flow just a few seconds will blister or destroy the hoses?

Thanks

88 PS190
08-24-2006, 11:24 PM
That's why he said to look for obstructions, if its starving for cooling already then its closer to failure when something goes wrong, really it should put up to it fairly well assuming its not buring hot to begin with. And often when an impellor shreds the bits and pieces go all over.

I'd check the hoses downstream of the impellor not just the trans cooler. And the rubber hoses are cheap compared to the fiberglass mufflers.

edwinfuqua
08-24-2006, 11:34 PM
You got that right! The mufflers look good. I just made one big mistake when installing the straight hose that goes to the inserts. I cut 'em off to fit, I should have cut them in two 24" lengths because it's adjustable, sliding the pipe back and fourth. I ordered a new straight pipe and am replaceing it Friday or Sat. I also cut the manifold rubber in two 24" tubes also. I think this is going to cause me to make some room for the exaust behind the hood but with the extra length in the straights at the end maybe not. I figure less bend the better. I've thought about replacing the mufflers w/ stainless pipe and wraping it with fiberglass header tape. You know that 454 would run better like that. BTW, I also had to make new flappers, I was able to save the inserts that are unavailable as far as I know. I make them from tractor trailor flaps from behind the rear tires.

TMCNo1
08-25-2006, 11:46 AM
If your boat still has the original thru-hull exhaust fittings, you can get replacement exhaust flappers from a Mastercraft dealer or Discount Inboard Marine [www.skidim.com] among other places.

ski_king
08-25-2006, 12:03 PM
Check the hose between the oil cooler and the water pump. You may have sme obstruction there. If the water pump was ever hooked up backwards (and it can happen on a PCM) parts of the impeller will be in that line.
That could cause lack of need flow at WFO.

east tx skier
08-25-2006, 12:09 PM
If you fried the impeller, start looking for the pieces everywhere upstream from the water pump as well. They have a tendancy to get stuck wherever they can and obstruct flow.

edwinfuqua
08-25-2006, 04:13 PM
I've tried to get new through hole fittings and flappers from a MC dealer and discount inboard marine (who are great folks) but my system is 4 inch ID and the flappers have a 1/4 moon stainless steel gaget that holds the flappers in place w/ 2 screws. The flappers are 5" OD. They don't seem to be available anywhere for this '85 MC. I was told by MC that it was a special order 'barefoot special' edition w/ the 454 HO so the exaust is a little different. I think I can make everything work though. Made my own flappers and cleaned up the through hole pieces.

edwinfuqua
08-25-2006, 04:17 PM
Check the hose between the oil cooler and the water pump. You may have sme obstruction there. If the water pump was ever hooked up backwards (and it can happen on a PCM) parts of the impeller will be in that line.
That could cause lack of need flow at WFO.
I've replaced all the hoses, and I will check the direction of flow on the pump. Everything was working OK untill my impeller picked up some thick mud and wore out, then after replaceing it the belt slipped at WOT then after that the circulating pully broke at WOT. I'm thinking Everything will be ok as long as I don't loose the pump pressure again.

edwinfuqua
08-25-2006, 04:20 PM
1234567890

ski_king
08-25-2006, 04:26 PM
I've tried to get new through hole fittings and flappers from a MC dealer and discount inboard marine (who are great folks) but my system is 4 inch ID and the flappers have a 1/4 moon stainless steel gaget that holds the flappers in place w/ 2 screws. The flappers are 5" OD. They don't seem to be available anywhere for this '85 MC. I was told by MC that it was a special order 'barefoot special' edition w/ the 454 HO so the exaust is a little different. I think I can make everything work though. Made my own flappers and cleaned up the through hole pieces.
I think if the part can be found skidim can find it for you.
But, if all else fails you may want to try a CC dealer. If I remember correctly they used a 4 in single exaust for many years, they might have one available.

By the way, please psost some photos of your 85!

edwinfuqua
08-25-2006, 06:00 PM
You can find some of them at
]http://computeralarm.com/boat/454.htm (http://computeralarm.com/boat/454.htm)

This is when we resealed the deck to the hull after cleaning out all the old caulk. After that we installed new rub rail.

edwinfuqua
08-29-2006, 01:55 AM
LATEST UPDATE:
Just about had it all back togather and my son was helping me when the left exaust angle broke off! I started checking everything and desided it was time to put the hood on and check out where everything is suppose to go and the right one broke!

I have a friend here in Athens, GA that runs a fab shop. He is making me two new aluminum straight pipes with the 45's on the end like the original, should have 'em later today. If I can figure out how to post pictures I'll post some of them.

Does anybody know exactly how long the fist set of 4 inch rubber hose should be? I think it is something less than 24" but would like to know without having to cut a little and cut a little more until they fit. I think the first time we cut 'em off too short, about 19". This last time I was trying to get 24"s to fit on each side.

TMCNo1
08-29-2006, 01:15 PM
I have a new set of 3" for a 1984 that was given to me as a spare that are 18" long and from MC. My '89 has 18' long hoses from the riser to the muffler, so I would say, somewhere around 18". I don't see where 4" would be much different!

edwinfuqua
08-30-2006, 12:21 AM
Good deal, so I know it less than 24". that's about 6 inches off from cut in half.... that's what I needed to know. With my new straight pipes I'm going to look for about 4 to 6 inches off half pipe that is 48 inches. Thanks, I'll be more carefulll.
Come over to lake Russell near the GA SC line. nice lake.

Thanks.

Edwin

edwinfuqua
09-03-2006, 03:50 AM
I have a new set of 3" for a 1984 that was given to me as a spare that are 18" long and from MC. My '89 has 18' long hoses from the riser to the muffler, so I would say, somewhere around 18". I don't see where 4" would be much different!

Well it worked out positively perfect at 18". Of course it took a bunch of hulkamania to get it installed. The second or Starboard side was much easier. I guess we are just getting the feel of installing this stuff.

BTW, the new aluminum pipes are working great, no leaks and it's not much louder. We tried to get some video today and we got some but the operator was in need of more training.

I changed the prop to a 13.5x19.5 4 blade and I can get about 5K RPM top end. That was from a 14.5x22 4 blade. I can't make up my mind about the prop. Seems like they both are good but the thicker one seems to have more or stronger pull power, but might cavitate. Heck, I'm impressed with both. A friend loaned his Pro jet ski to my son and I let him drive my boat, he took off slow and I said 'HIT IT' when he did I was a little late in looking for something to hold on to. Finally got the windshelk and then the towbar and kept from ending up in the back seat.

If I could ever figure out how to post video and photos I would do it here but until then I will post them in a link to my web that I mentioned in an above note.

The last time I ski'ed was 33 years ago. Got up first time on single ski, now I can ski off the BF-Bar w/o any trouble but today I got up and then immediately crashed. @#$$%@#$#$. That was a deep water start, I'm still good on the BF-bar...OK.

This little girl wanted to learn so I put the bar out and had a knee board. Five miles she skied on it eventually using the short rope then to my supprise she stood up and was like surfing on the board. She went like that for a mile or so standing up on the board. My wife who had the video camera had hi-tailed it ahead of us to the dock. I wisk I had the camera in the boat, I was impressed.

A local guy who I haven't seen in a year just showed up with his jets and we met up eventually close to the DAM. He ski'ed and was doing 360's left and then right. That make my day but I need to get the camera in my boat, without the screaming little girls who all hung on to the bar and two of them lost their pants, they said, suddenly they realized they were not lost and got 'em back on. They weren't lost just around their ankels I guess. That was funny.

On temps for the engine; I had drilled 3 1/16" holes around the thermostat and the temp would go from 130 to 160 back and fourth. This last trip I has redrilled the holes to 1/8" and the temp never got above 130 and did not move up or down. I have a new t-stat and am going to drill 2 1/16 inch holes and one 1/8" hole and see if I can get the temp to get stabel at about 160dF.

Okay, all for now I will edit the screaming out and post the video when I figure it out.

Replacing exaust hose and pipe is an extreamly difficult job. I am going to document the easiest way we found in another post to this thread.

Edwin

edwinfuqua
09-06-2006, 02:48 AM
Well, the aluminum pipes worked very well, difficult to install like all the rest but 'am getting good practice doing it. Thank God I had a strong hand to just show-up while doing the install.

BTW, drilling out the 1/16 holes to 1/8th lowered my high temp and never moved above about 130 or so (who knowes with an electronic gauge) it seems. I think I am going to solder up one of the 1/8th holes and see how it goes this weekend. It's going to be great on lake Russell again. I have some video and some pics but I don't know how to upload them to the site.
Edwin

edwinfuqua
09-06-2006, 02:52 AM
I have a new set of 3" for a 1984 that was given to me as a spare that are 18" long and from MC. My '89 has 18' long hoses from the riser to the muffler, so I would say, somewhere around 18". I don't see where 4" would be much different!

You are right the 18" hose length was perfect. Not that it was easy to install but you are correct. 18" is exactly what fits correctly and the straight pipes work perfectly. Not that much louder than the fiberglass original pipes, my hearing isen't that good I guess. Anyway, the flapps I made and the pipes gave good performance last weekend. Thank you for the information.

My new Avatar is doing a wake monster, just having fun trying out the new prop (13.5x19.5x4 blade apposed to the once existing 14.5x22x4 blade) it seems to give more RPM's but I think it is a bit too small for the HP. I'll post more photo's as soon as I can figure how.

Thanks, Edwin