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Message |
    
Steven Phillips
Visitor
| | Posted on Thursday, November 15, 2007 - 10:02 pm: | 
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I experienced a exhaust hose failure that prompted the replacement of the old wire reinforced hose. What's strange is 30 hours later the new hose also failed. Upon inspection, heat was the obvious culpret. The damaged spot was at the end of the wet elbow. While running the 120 HP Lehman a good flow of sea water ruled out back pressure and poor watering. The elbow was inspected and found to be more corroded on the hot side. The hot side? During trouble shooting my laser thermometer found most all the elbow at 95 degrees while a small spot near the damaged hose ran at 300 degrees! The design was simple and water seems to splash about enough to cool the elbow but after a thurough cleaning the unit remains hot in spots. Whats worse, the new replacement is hot in the same spot. I attached a 3/4 inch shore hose to the elbow where the sea water normally enters and cranked it on. 100 PSI and the elbow remains near 300 degrees on the side the water is discharged from. Ideas? |
Michael A. Vogt
Member
Username: mikee007
Post Number: 4
Registered: 09-2007
| | Posted on Thursday, November 15, 2007 - 10:28 pm: |
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Steve, Your question brings up lots more questions. The normal hot side on the lehman exhaust elbow part number 1A371 or 1A372 is on and around the bottom underneath the water injection. It will be always be hotter right there and typically burn the paint. What elbow do you have? How do you know the water flow is correct? Have you cleaned or checked the oil coolers, heat exchanger, thru hull, strainer, muffler, speed scoop, raw water pump, etc.? Mike |
Steven Phillips
Visitor
| | Posted on Saturday, November 17, 2007 - 09:16 am: |
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Mike, I will get a number for you. The three heat exchangers have been serviced and are now ready for installation today. Thru hull, OK strainer, OK. pump, OK. Speed scoop? I had not thought of further inspection of the muffler as water flow seems normal and gas escapes as it always has, what more should I look for?
Thank you so much for your response,
Cheers Steven |
Michael A. Vogt
Member
Username: mikee007
Post Number: 6
Registered: 09-2007
| | Posted on Saturday, November 17, 2007 - 11:10 pm: |
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Well, I thought this last post was replied to earlier - things like speed scoop being clear, the reality of "water flow seems normal", wire reinforced intake waterlines, and some digital pics of Steve's system. Mike |
Steven Phillips
Visitor
| | Posted on Sunday, November 18, 2007 - 01:06 am: |
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Mike, I Serviced the cooling system, (all your recomendations) accept the muffler. Upon running the engine at cruising speed we ran up to 379 degrees! The hot spot is on the bottom of the elbow as you noted. the unit number is B12S20. Please elaborate on what I might look for in the muffler and south of that (back pressure?). |
Michael A. Vogt
Member
Username: mikee007
Post Number: 7
Registered: 09-2007
| | Posted on Sunday, November 18, 2007 - 09:56 am: |
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Steve, post some detailed digital pics of your engine. I don't know what B12S20 is. What type of muffler do you have - inline, lift style, fiberglass, or SS. Mike |
michael walters
New member
Username: motion30
Post Number: 2
Registered: 11-2008
| | Posted on Monday, November 03, 2008 - 08:03 pm: |
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The replacment elbow I bought has no cooling water passage at the bottom of the elbow. My hose was burnt as well. I installed high temp hose ( blue hose) on the exhaust |
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