Total newbie with a mercury 115 2 stroke... lay it on me!

[Renken1600]

Hey everyone,

Purchased a 1989 Renken 1600 Bow Rider from a friends Dad that came equipped with a 1989 Mercury 115 2 stroke.

Before the season ended and we took possession, we went for a rip and everything seemed to check out. Admittedly, he was not much of a shade tree mechanic and had his motor serviced and winterized every year. Having never owned a boat or an outboard... I did make some observations to myself which came with its own set of questions.

1) the idle seemed to be pretty low... sounded like it was struggling to stay running when cold but ripped around the lake... at one point when we switched over at the helm, I had brought it down to idle and it stalled out... the throttle seemed really stiff...started up just fine and ripped again... never stalled after that. He mentioned that 115's don't like to putter along... my vw's like a good drive on the highway to clear things out but still run fine in city driving...

2) Are two strokes of this vintage generally noisy or "clunky"... it reminded me a bit like an air-cooled beetle... there were no discernible knocks or anything... it just seemed to be less than smooth at idle.

3) I've been doing a lot of reading and found a manual for my engine... could you give me a run through of what I should service this spring time... everything seems to be relatively affordable i.e.gear oil, impeller, water pump, spark plugs etc. What is a typical outboard tune up and where is the best place to get parts?

Thanks you for your help and time!

 

[racerone]

It omly runs on the top 2 cylinders when idling.------Before spending any coins do a compression test.

 

[Renken1600]

It omly runs on the top 2 cylinders when idling.------Before spending any coins do a compression test.

Thanks racerone, is it safe to do a compression test without the water? I realize I will disengage the fuel delivery... just wanting to be informed.

Anyone have their spring tune up rituals they are willing to share? Also curious about universal and general parts places online.

 

[racerone]

Some will argue.--------The term " tune up " is a thing of the past.------Make sure carburetors are CLEAN.-----New sparkplugs ----Change gear oil .----Install new impeller for water pump.------Make sure oil pump delivers correct amount of oil into the fuel.-------Make sure motor warms up when started.------That is about it.-------Ignition is electronic , no adjustment.----Carburetion rarely needs adjusting.

 

[havoc_squad]

If it's new to you, recommend doing all the maintenance items listed below before using it.

Maintenance intervals below:

Decarbon annually

Fog it for stoarge if it sits for more than three months without running. Otherwise no need to fog it.

Lower unit lube inspection before freezing weather starts to verify no water in gearcase.

Replace the lube then or every 100 hours, whichever comes first.

Every two years or 100 hours, water pump replacement. Whichever comes first.

Carb rebuild, depends. If you run ethanol gas, definitely rebuild it every two years. Ethanol is rough on carbs and fuel lines.

Ethanol free gas stablized, you might get 3 or 4 years before carb rebuild is needed.

Spark plug replacement interval is probably based on condition and number of hours more than anything else.

Light use with freshwater, you probably won't change them for 3 to 4 years unless you foul them out quickly.

If it is two stroke and it auto mixes the oil and gas, you must inspect and check that system is functioning correctly per factory service manual directions at least once a year.

Otherwise it could crap out on you and by the time you react to the alarm, the powerhead usually has permenant damage from lack of oil.

That's why many disable oil injection and do pre-mix only. The cost, worry, and effort to maintain it isn't worth the benefits it gives.