Classic AquaSport
Aquasport Model Rebuilds, Mods, Updates and Refreshes => 270/281/286/ 290 XF/Osprey Owners Group => Topic started by: manifishdestiny on September 30, 2012, 08:15:56 PM
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Today I ran the 86 290 TM twin mercruisers and I noticed right out of the gate my starboard engine was smoking/steaming a lot more than usual and definitely more than the port engine although port engine was smoking. Only happened over 1000rpm's. While trolling, at 3.5 - 5.5 knots there was no smoke/steam. I also noticed the oil temp was consistently stuck at 80 psi while the port was running at 40 psi give or take. Are they related? Where should I start. Outside temp 70 Water temp 71. Any help is appreciated as always.
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Maybe a spun main or rod bearing. Any noise? The high oil pressure is a clue.
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Thanks for the reply. No more noise than usual but it seems more vibration/shaking.
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Excessive steaming to me would indicate warmer exhaust gasses than usual. And the vibration...hmmm, given that you haven't grounded the boat as of late and maybe bent a prop shaft or tweaked a strut, those, with the oil pressure, says something is amiss in the starboard motor. Realizing oil pressures will start high, then come down after warm-up.
Just my 2 pennies, but the starboard motor doesn't sound good...and we can't even hear it!
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Excessive steaming to me would indicate warmer exhaust gasses than usual. And the vibration...hmmm, given that you haven't grounded the boat as of late and maybe bent a prop shaft or tweaked a strut, those, with the oil pressure, says something is amiss in the starboard motor. Realizing oil pressures will start high, then come down after warm-up.
Just my 2 pennies, but the starboard motor doesn't sound good...and we can't even hear it!
I guess its time to call a mechanic??
Thanks Bob.
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Anthony,
Let's look at the basics first. Do the oil pressure gauges for both motors react the same at initial start up, then only the port comes down to 40? Does the starboard fluctuate at all, given load, speed, what have you? Could be a sender or gauge if it goes to 80 and stays, like it's frozen.
Vibration. If it ain't to much of a beeetch, remove the coupling bolts at the tranny output flange, pull the shaft back, then bring it back in and see what your clearances are. I used to align (at Stamas) to .0025", but .004 will do you fine. Maybe something got out of whack just a smidge and is causing a bit of mis-alignment, hence the vibration. Good time to re-pack the stuffing boxes if they haven't been done in a bit...
Are your motors FWC? What are the temp gauges doing in relation to each other? Do they start out the same then the starboard motor starts to climb way quicker than port?
And what condition are the elbows and risers?
Just some food for thought...
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Have you serviced the sea water pump recently? What do engine temps look like? Excessive steam from the exhaust often is caused when the sea water impeller goes bye-bye and the engine gets hot due to a lack of sea water flow for cooling. If you replace the impeller - make sure you find all the fins/vanes that broke off - you don't want one of those rubber pieces clogging up the cooling water flow.
The high oil pressure is puzzling - 80 PSI at idle is hard to believe - it's hard for a standard oil pump to pump that much oil at idle. 80 PSI at higher speeds potentially indicates a stuck oil pressure relief spring on the oil pump - and you have to take the pan off to get to it - PITA on most boats. How does the oil look - normal or creamy? Oil contamination from a leaky head gasket can cause high oil pressure and also could contribute to overheating.
Note: Faulty oil pressure senders are often the problem with weird oil pressure readings - I would replace the sender (it's about a $20 part) before tearing into the engine.
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I am going to check all of the following suggestions above by starting with the simple first and hoping for the best. Time down equals no money for me so the easier and quicker the better however I have learned to prepare for the long and expensive. Thanks again for all the great advice on this site. I will keep you all posted.
Anthony
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Anthony,
Let's look at the basics first. Do the oil pressure gauges for both motors react the same at initial start up, then only the port comes down to 40? Does the starboard fluctuate at all, given load, speed, what have you? Could be a sender or gauge if it goes to 80 and stays, like it's frozen.
Vibration. If it ain't to much of a beeetch, remove the coupling bolts at the tranny output flange, pull the shaft back, then bring it back in and see what your clearances are. I used to align (at Stamas) to .0025", but .004 will do you fine. Maybe something got out of whack just a smidge and is causing a bit of mis-alignment, hence the vibration. Good time to re-pack the stuffing boxes if they haven't been done in a bit...
Are your motors FWC? What are the temp gauges doing in relation to each other? Do they start out the same then the starboard motor starts to climb way quicker than port?
And what condition are the elbows and risers?
The starboard oil gauge goes to 80 and stays regardless of speed and the port bounces between 20 and 40 depending on speed.
Gaskets definitely need replacing on the risers as there is some weeping going on. My motors are Raw watered cooled.