Merc 175 saltwater

[jfgln]

Hi Guys, I'm looking at a 1997 20' Trophy that has a Merc 175 Saltwater series outboard. The boat looks good, but I don't know much about this particular outboard.

Any issues with this outboard?
What should the idle speed be? It seemed a bit high when ran on the hose, 900ish. We are going on a test drive tomorrow.

Thanks,

Jeff

 

[sschefer]

Re: Merc 175 saltwater

If its a Blue Water Series engine and has been used in Saltwater primarily and frequently then check the steering arm (swivel pin) down at the bottom mount. It wasn't until later that Merc decided carbon steel and salt water don't make a good match. The new stainless steel replacement is 600.00.

I just tore down a 99 200 Blue Water that was run in saltwater all the time but was also well taken care off. I got lucky and tearing it down wasn't too bad. If yours isn't well cared for it will probably be just about on it's last leg. 3-5 years on salt is about all they can take when the owner just runs them and doesn't go out of their way to care for them.

 

[Mercs and such]

Re: Merc 175 saltwater

absolutely right sschefer! those mercury saltwater's never stood a chance if it sat uncared for. If the decals are sun faded you can almost guarantee that the boat sat for a long time which indicates gummed carbs in most cases and will only leed to more, worse problems so be prepared to throw some money into it. 900= a lost gear case. almost all mercury's idle between 500-650RPM's. You can adjust the idle by loosening the idle speed screw, keep adjusting till the tac drops to around 600. 500 is the range of cut-outs and hard starting in my opinion. On your test run, be alert for specific engine sounds. If there is a louder than normal noise when shifting, the lower unit might give out, if its from the powerhead, main bearing might go bad on you. Just pointing out a few things.

If everything looks good, compression checks out above the bare minimum of 100 even on all cylinders your in the go just get that idle set way lower.