1988 175 HP Mercury won't crank

[kneumeier]

My son was given a 1988 Ranger bass boat with a 1988 175 HP Mercury. The motor has not run in two years since it had a few wires catch on fire. After inspection, all the wiring was there but some insulation had melted. I repared it and when I tried to crank it was hard to turn over by hand (with 3/8 ratchet). With two cars trying to jump it, the engine would just bearly turn over. With the plugs out, it turned over much easier. I have spark, but with the plugs installed, I can't get it to turn over (very slow is all). I've even tried to see if it will fire with half the plugs out. It still won't turn over like I thought it hould. Also, when I first started to crank it, I used the key and then it stopped working so I jumped across the solenoid. The best it ever did was after I put gas in the cylinders, it "popprd" once. That was it. What do I try next?

 

[Barnacle_Bill]

Re: 1988 175 HP Mercury won't crank

You need to find out why it is hard to turn over. Remove all the plugs and try to turn it over by turning the flywheel by hand. It should turn with just a little resistance. If it is still hard to turn over, drop the lower unit and try again. This will tell you if the problem is in the motor or the L/U. Let us know what you find.

 

[kneumeier]

Re: 1988 175 HP Mercury won't crank

how do I drop the lower unit?

 

[Unbalanced]

Re: 1988 175 HP Mercury won't crank

Sounds like you either still have a wiring problem or the battery cable terminals are corroded/oxidized. Instead of jumpering the battery that's in the boat, hook the jumper cable right to the starter and see if it turns over any faster.