Probem after tilt up engines sws 98 250

Robert Finch

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Joined
Nov 24, 2004
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13
I have twin 98' sws EFI 250's. After a long hard day in rough seas off shore. Engines running fine all day everthing was wet but they ran great. (I clean O2 and do plugs after about 75hrs.) Question is: after<br />stopping in mid trip home I thought I ran over a lobster pot. I turned both engines off and bought them both up to max tilt to check props. I did not hit the pot all was clear, but when put back down and restarted they ran exptemely poorly (both)they got me home safe(yamahas)but would stall etc in harbor, fuel etc.was fine and the read out was 14.4 volts. I have not idea way this stop and engines tilted up would cause this. Does anyone have any ideas?
 

rodbolt

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Sep 1, 2003
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20,066
Re: Probem after tilt up engines sws 98 250

hello<br /> its time to remove and inspect the plugs. if it was rough with the engines off its possible to force water up the exhaust into the cyl. or you have some contamination of the fuel and its in the vapor seperators now. very common in rough seas.<br /> run the basics of spark and compression tests and let us know
 

rodbolt

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Sep 1, 2003
Messages
20,066
Re: Probem after tilt up engines sws 98 250

hello<br /> the high pressure pumps have a filter that needs periodic service. the low pressure pumps I reccomend replacing every 3 years or so. the t-stats,water pump and pressure relief valve grommet every other yaer at least. if they are 25" motors inspect the bushing in the mid-section every 5 years and at every water pump service. the high pressure pumps I run till they quit. usual cause of failure is sitting with nasty fuel or run dry for a length of time. high pressure pumps are about 750 from yamaha now. keep them greased and the trim senders sprayed with fluid film. check the white plastic oil rod links for cracks. test the red plug caps for proper Ohms every 3 years or so. change the remote oil filters every year.<br /> other than that its a matter of careful inspection and fix things before they break. if you have never changed the cooling passage pencil anodes odds are you will have to remove the heads to get them out now.<br /> any thing else ?
 

Robert Finch

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Nov 24, 2004
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13
Re: Probem after tilt up engines sws 98 250

rodbolt, you were dead on, in the rough seas with heavy rain, the full tilt, water much have gotten in cyl. Did all 12 plugs and their now running well. Thank you. One more question, as noted I am all over the O2 and plugs, however could you give me a quick list of things I should do with two engines that now are 5 year old, not the general maintenance(gear oil, O2 etc. I am on top of that stuff.) But since I take this boat far offshore I want to make sure I on top of preventing problems. So from what I have read from you, I should replace fuel pumps, high pressure and low correct? Are there other things I should replace or do after 5 years. Thanks again...
 

Robert Finch

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Joined
Nov 24, 2004
Messages
13
Re: Probem after tilt up engines sws 98 250

Thank you very much, got it. "t-stats" are the only thing I am not sure about, what they are what they do etc.? (I am sure it is short for something?)
 
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