Mercruiser 170hp- starter just "clicks"

[webnetxpress]

I am trying to get an older boat running again... It is a 1985 Mercruiser 170hp, 4cyl I/O.<br /><br />Sometimes it will crank and start with the key, other times I'll just hear a "click" at the engine (not necessarily by the starter). This is on a fully charged battery.<br /><br />If I short out (with a screwdriver) the two terminals on the starter, it will crank and then start.<br /><br />Does this mean there is a bad solenoid? (Does this engine have an external solenoid - away from the starter?)<br /><br />Could it be anything else - wires, etc?

 

[Walt T]

Re: Mercruiser 170hp- starter just "clicks"

they have external relays. Probably on the back wall somewhere.

 

[MrBill]

Re: Mercruiser 170hp- starter just "clicks"

Your engine has an external solenoid switch mounted on the starter, here's a schematic of your starter.<br /><br />http://www.mercruiserparts.com/Sh ow_Pictures3.asp?dnbr=%2012488&ivar=images/CRUISER/12488/5.png&inbr=908&bnbr=20&bdesc=STARTER+MOTOR+ASSEMBLY<br /><br />Chnaces are very good that the brushes are worn and are contributing to intermittent starting. After turning the key and getting the clicks, try tapping the starter (not too hard) with a hammer or short length of pipe, then try the key again, if it starts, its probably the brushes or worn spot on the armature. New stater's about $170, only slightly more than a rebuild. <br /><br />The chances of it being a bad solenoid are very small, there's little that can go wrong and in a new starter the internal componenets (brushes, armature, etc) would wear far faster than the solenoid components. If it always starts when jumping the contacts though, you could be right. Is this the first time the starter's been a problem?? My 1989 3.7L went for the first time in 2002. Good luck and let us know the eventual problem.

 

[kcole683]

Re: Mercruiser 170hp- starter just "clicks"

You have a slave selenoid mounted on the engine in front of the starter motor. If you can jump the large terminals with a large jumper wire you can bypass the selenoid and the starter should crank. If it cranks every time you bypass the slave selenoid then the selenoid is probably the problem. Make sure you replace it with a sealed marine unit,the only place I could find it was at a merc dealer. NAPA has selenoids but they did not have an application for the resistance wire bypass circuit for the points ignition.<br /> Don't use a jumper if there are any gas fumes in the engine compartment!!!<br /><br />You might clean up all of your connections and check your battery cables for high resistance.<br />A weak battery will sometimes play these kind of games also.