I have an older early 1990's 75HP Mariner boat motor and I'm looking for advice.
It's always been a super reliable motor, we have done minimal maintenance to it over the years and usually we just go out to the cabin in the summer, pop in a battery and hit the water and away we go. This last year, the lack of maintenance I think has finally kicked us in the ass.
It's having a hard time running. We can get the motor to fire up, idles kindof rough but it does idle, but putting it into gear often stalls it out. Sometimes if you rev it up and then as soon as it idles down put it in gear it'll catch and off you go. Anyway you cut it, not overly reliable.
I did some checking and it seemed like it was getting WAY to much oil, the plugs were old likely my dad was the last to replace them so probably 10+ years old so I put new plugs in and fired the motor up and shut it down probably within a minute and checked the plugs and they looked soaked in oil. I noticed there is a valve or pump on the oil which was adjustable by moving the threaded rod so I spent some time tuning and tweaking it, and basically giving it less oil (motor was on dry land with ear-muffs on providing water) and we got it to the point it would fire up nice, idle decent, and there was still some blue smoke and the plugs had a bit of oil on it so I wasn't worried about lack of oil, but taking it out on the lake it was still not right and having a rough time. And I didn't like restricting the oil past the "marks" on the valve cam.
So... it's got issues. I figure best thing to do this year is to start off by replacing the fuel filter and I ordered a fuel pump diaphram kit since that's cheap/easy and being almost 30 years old probably it's not working very well either. Once I get the fuel pump and filter replaced I'll put the oil valve back to where it was but I'd like to properly adjust it if possible, but I don't know how? I've heard/read somewhere to run pre-mix, and remove the oil line and run it to a measuring cup, then letting the motor idle for like 10min measure the amount of oil in the cup and tune that way?
I'd like some of you guys advice if I'm going down the right path or if there is other things I should be looking into. I work on vehicles and farm on the side so I'm very handy with pretty much anything mechanical, but oil injected 2 stroke boat motors... can't say I'd done much with them.
I've attached some pics, of the motor, the before/after on the oil cam, and just an overview.
It's always been a super reliable motor, we have done minimal maintenance to it over the years and usually we just go out to the cabin in the summer, pop in a battery and hit the water and away we go. This last year, the lack of maintenance I think has finally kicked us in the ass.
It's having a hard time running. We can get the motor to fire up, idles kindof rough but it does idle, but putting it into gear often stalls it out. Sometimes if you rev it up and then as soon as it idles down put it in gear it'll catch and off you go. Anyway you cut it, not overly reliable.
I did some checking and it seemed like it was getting WAY to much oil, the plugs were old likely my dad was the last to replace them so probably 10+ years old so I put new plugs in and fired the motor up and shut it down probably within a minute and checked the plugs and they looked soaked in oil. I noticed there is a valve or pump on the oil which was adjustable by moving the threaded rod so I spent some time tuning and tweaking it, and basically giving it less oil (motor was on dry land with ear-muffs on providing water) and we got it to the point it would fire up nice, idle decent, and there was still some blue smoke and the plugs had a bit of oil on it so I wasn't worried about lack of oil, but taking it out on the lake it was still not right and having a rough time. And I didn't like restricting the oil past the "marks" on the valve cam.
So... it's got issues. I figure best thing to do this year is to start off by replacing the fuel filter and I ordered a fuel pump diaphram kit since that's cheap/easy and being almost 30 years old probably it's not working very well either. Once I get the fuel pump and filter replaced I'll put the oil valve back to where it was but I'd like to properly adjust it if possible, but I don't know how? I've heard/read somewhere to run pre-mix, and remove the oil line and run it to a measuring cup, then letting the motor idle for like 10min measure the amount of oil in the cup and tune that way?
I'd like some of you guys advice if I'm going down the right path or if there is other things I should be looking into. I work on vehicles and farm on the side so I'm very handy with pretty much anything mechanical, but oil injected 2 stroke boat motors... can't say I'd done much with them.
I've attached some pics, of the motor, the before/after on the oil cam, and just an overview.