Recent content by rndcomp

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    Merc 170 - Water in the Oil

    I have a 1987 Merc 170 I/O with what appears to be water in the oil. The engine is Fresh Water Cooled with a 4" heat exchanger. There is an after market alternator upgrade and a Mallory electronic ignition has been installed. I have been using the boat this summer and while there have been a...
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    Engine Dies ---- electrical failure????

    87 Merc 170 - FWC - Electronic Ignition - Aftermarket charging system After running the engine for about 45 minutes at 75% power, it dies on me... No warning, just dies. The temp is great (around 170) and the the oil pressure looks good as well. If I let the boat sit for about 5-10 minutes...
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    Riddle me this...Riddle me that.... Where is all my oil at?????

    THE BILGE..... That's where!!!!! Now the question is why. I have a Merc 170 (1987) with FWC and everytime I take the boat out and run it for a couple of hours, the bilge fills up with oil. This would probably explain the slight knocking that I am hearing (see earlier post). My question...
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    87 Merc 170 - Slight knocking sound

    When my 87 Merc 170 engine is running, I hear a very slight knocking sound and I am not sure what it is. Since I am not really a mechanic, this may be normal, but I am thinking not. This happens at both idle and when the engine is revved, and the knocking will change with the engine speed...
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    Blower Configuration

    I have an '87 SportCraft Bowrider and want to know how the blowers should be set up. I have two air scoops on the rear of the boat (one on each side) and would like to know if these are air inputs, or if these are where the blower pushes the air out (or maybe one of each). I know my blower...
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    Possible to test an impeller???

    I am having an overheat issue with my 87 Merc 170. As a test, I disconnect the raw water input line to my heat exchanger and then started the engine (with muffs). There was water coming through the line, however, I do not know if this is a valid test of the stern drive impeller. Can anyone...
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    Using an Automotive Thermostat in a Boat???

    My family is dying to get out on the water tomorrow and all of the marine shops in the area are closed. Is there any harm in using an automotive thermostat (same temp value) for a day. This will also help troubleshoot an overheating problem. If the problem is fixed, I would plan to buy a...
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    Overheating 87 Merc 170

    I am starting a new thread because my last one got pretty long. OK, now that I know compressions are OK (125,130,125,125) I need to focus on my overheating issue. When the engine was running on muffs at idle for about 15 minutes the oil pressure was right @ 60 psi and the temp slowly climbed...
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    Making Fiberglass shine again

    Any good ideas on how to bring back the luster and shine of an older fiberglass boat? Thanks!
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    New Alternator = Sparking Battery Terminals ????

    I just installed a new alternator for my 87 Merc 170 (it already had the aftermarket charging, I only replaced the alternator), and now I am getting sparking at the battery terminals. There is more to this story. I am also trying to test the compression of my cylinders so I have removed the...
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    Best Plugs for an 87 Merc 170

    My manual says that I should use AC Delco R42TS plugs in my 87 Merc 170. Does anyone have good or bad experience with these? Are there better ones that I should look at? Thanks!
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    Cracked Block - or - Blown Head Gasket

    OK, here we go. First, I am not a mechanic, not even close. The beginning of the story goes like this, I bought a boat sight unseen. I took it out on the water and without knowing it, had a FWC coolant loss as a result of a bad front cam seal. This led to an overheated engine, which is...
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    Mercruiser 170 - Front Cam Seal Replacement

    I need to replace my front cam seal (since coolant is leaking from the weep vent) and wanted to know if this is a straight forward project, or something that should be done by a mechanic. I have some experience working on engines, but not much. In addition, is the fact that I have the...
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    Normal Operating Temp for a Merc 170

    Can someone out there please validate that the normal operating temp (at idle) for an 87 Merc 170 is around 170 degrees. I am pretty sure that I read this somewhere. Also, and I apologize the dumb question, if I were to remove the pressure cap off the FWC reservoir, should I expect to see the...
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    Can a bad alternator = poor engine performance?

    Just a quick question, can a bad alternator cause poor engine performance due to a lack of consistent voltage? Thanks!:confused:
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