1987 40hp mariner idle adjustment

[striperangler9]

I just purchased a 1987 40ELO 40hp mariner twin carb oil injection. The oil injector has been removed by the previous owner. The engine runs great but idles a little high. I was wondering how I can adjust the idle. Also I was going to replace the impeller. She spits water great now but the person I bought the motor from said it sat for a couple of years. Should I worry about that this season? I know this is a really a yamaha and i have a litle experience in merc, force outboards. Can anyone give me the procedures on removing the lower unit before I attempt. Thank you for looking at my posting

 

[AMD Rules]

Re: 1987 40hp mariner idle adjustment

Post your serial / model number for identification of appropriate procedures.

I would recommend inspecting, and likely replacing the impeller. Cheap insurance.

 

[KurtG]

Re: 1987 40hp mariner idle adjustment

I just did the water pump on mine ('86 40HP ELO twin carb w/oil blending removed).

First be careful removing the bolts. The bolts holding the lower unit are cheap grade stainless that break easily. I ended up having to take mine to a machine shop and it wasn't cheap. If the bolts don't slide out easily, take a fair amount of heat to them -enough to start to burn the paint, and work them in and out to break them free.

Once you break the bolts free then you need to disconect the shift shaft. After that the lower unit will slide right off.

The parts weren't too easy to find for this model (ELO twin carb) and were pretty expensive (impeller alone is like $40 something or the water pump kit part # 12-84363T was $82 from boats.net). It took me a couple weeks to get everything as several vendors didn't really have what they thought in stock. I needed to replace the pump lower housing (badly corroded), the oil and water seals along with the gaskets, impeller and thermostat. DougRussell was a better vendor for parts (knowing whatthey had in stock) but more pricey.

Lastly, make sure you use lots of grease and antiseize when you put things back together.