1995 Mercury 75 hp

[STIguy]

Hi There folks!

I just bought a 17 foot aluminum 1988 Crestliner "Bass Boat" (sorry not sure of the model name) that has a 1995 Mercury 75 HP outboard on it.

This is my first "big" boat.... The motor has been garage stored and winterized every year by the previous owner (or so I am led to believe). Are there any common problems I should be aware of or anything I should look out for with this motor?

Also, since I am new to the boating scene and really have no idea what to expect... if you guys have any tips or tricks to get the best performance/fuel mileage/reliability out of this thing please do share!

Thanks, the name is John. Glad to meet you all =)

 

[achris]

Re: 1995 Mercury 75 hp

Hi John,

Welcome to iBoats...

To get the best out of what you have.... Regular maintenance, clean fresh fuel, good quality oil and don't over-prop it.

Over propping is having a propeller on that is too big and won't let the engine run at the recommended rev at WOT (Wide Open Throttle). That doesn't mean you run at WOT all day. If you have too big a prop, then the engine is overloaded and you overheat and destroy pistons, real quick! And that will happen at any revs, not just WOT.

Other than that, have fun

Chris............

 

[STIguy]

Re: 1995 Mercury 75 hp

Thanks for the welcome Chris!

How can I tell if the previous owner changed the prop?

 

[achris]

Re: 1995 Mercury 75 hp

Next time you're out in the boat, when the weather is suitable, run the thing at full throttle... See what revs you're getting... Should be between 4750 and 5250. If it's lower than that, you need a prop with a smaller pitch, if it's significantly higher, get one with more pitch.... If your skiing, use a prop that is 2" (pitch) smaller than the one that gets the right rev range. Skiing is the hardest thing you can ask your engine to do....

Chris...........

 

[STIguy]

Re: 1995 Mercury 75 hp

One problem with that Chris... There is no tachometer on the dash.

How expensive/complicated would it be to get one installed?

Oh and I found out what model boat it is... It's a 1988 Crestliner Fish Hawk 160 if I'm not mistaken.

 

[achris]

Re: 1995 Mercury 75 hp

It's not difficult... But to ensure your engine isn't being overloaded, it's essential. Just cut the hole and connect 3 wires. You'll need a harness and the tacho... I don't know the prices of stuff in the US, but it shouldn't be more than about $150....

Chris............

 

[Barnacle_Bill]

Re: 1995 Mercury 75 hp

You can get a good tach for about $80 here in the states. Thats not installed. Also be advised that Merc has a TSP out for that motor advising that the fuel pump be rebuilt. It seems that ethanol causes the check valves to curl up and cause problems. The kits from Merc (about $20) comes with a new style check valve and instructions for installing them. They were causing mine to starve for fuel at higher RPMs.

 

[marty53]

Re: 1995 Mercury 75 hp

Just a note for fellow cheapskates-- I got a used faria tach on ebay for under $10 and made my own "harness" with just some female crimp ends to plug into the control. Works perfectly.

 

[achris]

Re: 1995 Mercury 75 hp

Just a note for fellow cheapskates-- I got a used faria tach on ebay for under $10 and made my own "harness" with just some female crimp ends to plug into the control. Works perfectly.

My kinda guy

Well done... Now, what revs you makin' at full tank?

Chris......

 

[marty53]

Re: 1995 Mercury 75 hp

i'm right at 5k RPM with my 16ft '91 Invader open bow with 1991 mariner 75hp 13x19 prop. orignal prop was merc 13x21 and i only got about 4650 RPM with that one.

 

[STIguy]

Re: 1995 Mercury 75 hp

You can get a good tach for about $80 here in the states. Thats not installed. Also be advised that Merc has a TSP out for that motor advising that the fuel pump be rebuilt. It seems that ethanol causes the check valves to curl up and cause problems. The kits from Merc (about $20) comes with a new style check valve and instructions for installing them. They were causing mine to starve for fuel at higher RPMs.

Thanks for the info! The motor seems to be running flawlessly so far... but where can I get more info on this?

 

[Barnacle_Bill]

Re: 1995 Mercury 75 hp

Thanks for the info! The motor seems to be running flawlessly so far... but where can I get more info on this?

You will have to get it from a dealer. There use to be a site that listed all of Merc's TSBs but Merc made them take it down. I guess they don't want us to know whats wrong with their motors.