2012 Mercury 115 Optimax running issues

[Mbrenegade]

Just purchased a 2012 Tracker Pro Glide v175 with a 115 Optimax serial number 1B913226. Engine has 44 hrs on it from what we were told. This is our first outboard boat. Filled up with premium fuel only took 42 litres so must of had lots of old fuel in it. Took it out for our first run and it stalled 3 times checked fuel ball it was soft. Pumped it up didn't stall after but was very sluggish and very slow out of the hole. The water temp in the lake was 47c so would that be an issue? Also the throttle seems very stiff and hard to move, I have to move it halfway through its range before it accelerates. Any answers would be appreciated!

[JOE54]

temp should not be the cause/ would have all the systems checked by a MERC serv center may have coil bad

[SilverFox579]

Don't use premium fuel, your Optimax is designed for regular. Check out this topic in the 3L forum FAQ (lots of FAQ topics there apply to all Optimax engines) - Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations


FUEL:
-All models- MAXIMUM ETHANOL CONTENT: 10%. Ethanol content may adversly affect engine performance.
-See "Mercury's View of Ethanol" on Sherm's board at: http://www.bbcboards.net/mercury-mot...nded-fuel.html
-Standard Opti's (ALL) 87 Octane MINIMUM.
-Standard 2-stroke Carb/EFI Models: 87 Octane MINIMUM.
-XS, XB or Racing PRIOR to 2006- CONSULT OWNER'S MANUAL! Most require High-Test!
>>>>>-ProXS and 250XS 2006-UP: 87 Octane MINIMUM. IF poor idle quality occurs, could can try 89 Octane (mid-grade) to see if quality improves.<<<<<
-300XS- Consult Owner's Manual. High Grade (minimum 91 Octane) fuel required!

Fuel Additive Recommendations:
-Stabilize fuel ANYTIME fuel will not be consumed and replaced within 15 days!!!
-Optis (ALL, including XS & ProXS): Quickleen in EVERY TANK OF FUEL. You CAN combine Mercury QuickCare or QuickStor Fuel System Treatment & Stabilizer with Quickleen. Use the recommended "dose" of each product per the bottle instructions. For anyone questioning Quickleen recommendation- see Service Bulletin 2001-12 (yes, it's been recommended since 2001!!!).
-Quickleen may be used in ANY Mercury engine- it helps to prevent/remove carbon buildup (primary purpose).

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"Mercury Component Cocktail"- for EVERY tank of fuel, whether or not your fuel contains Ethanol: (Chemically, this works much the same as the previously recommended (and now to avoid alcohol content) cocktail, and requires less components.) This is Don's Preferred "Cocktail":

-1oz Mercury QuickCare +
-1oz Mercury QuickLeen
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Per 5 Gallons of Fuel (in EVERY TANK).

In addition to the above, it is acceptable to add 150:1 mix of Premium PLUS in the fuel tank (for OPTIMAX engine models). This has been proven to benefit fuel system components by providing additional lubrication ONLY to the fuel system components (especially the direct injectors- which are often left DRY after engine shutdown).

(If leaving fuel in boat for more than 30 days, be sure to also add Mercury QuickStor).
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Fuel Selection:

Make your fuel selections based on the following criteria, IN THE FOLLOWING ORDER:

-High Traffic, Top-Tier (Name Brand) Fuel
-Appropriate Octane Rating (see above info)
-Lowest possible ethanol content (NEVER to exceed 10%).
-While it may be preferable to utilize a fuel that contains lower (or no) ethanol, use of fuels that are SUBSTANTIALLY higher octane can result in decreased performance, decreased fuel economy, and potential for carbon buildup. Higher octane fuels burn SLOWER and COOLER.

[Mbrenegade]

Thanks guess I will be draining the fuel tank and refilling with regular fuel. I just filled it with premium as was not sure how long the old fuel has been in the tank and wanted to bring the octane back up. Then bring it in to have it checked over if a coil is bad.

[SilverFox579]

[JOE54]

please report back

[Mbrenegade]

Thanks, I will let you know how I make out. When I get back out to where the boat is. Should be later this weekend.

[Mbrenegade]

Took boat out today with another friend who has a Optimax. Added the Merc fuel additives Merc quick clean and Merc quickcare and the Boat ran good today for some reason,but we only had time for about a 15 min run in it. Not enough time in the day these days. Also my friend says that I probably had an air lock in the fuel system that's why it would stall just after it got on plane, and after I pumped the ball up last week it may have pushed the air lock through. Engine still seems sluggish out of the hole. Was told that it may be propped to high. Next week going out with a 17 pitch to swap out the 19 see if that helps. On the throttle being stiff was told that is normal, just guess I am use to my Volvo Penta but will Keep you posted on this.

[JOE54]

10-4 what boat is it on/ might check boat brand or prop forums for prop selection

[SilverFox579]

Good practice to pump primer bulb before every engine start. There should be a tension adjustment on your control box. Might try that but based on what you said in your initial post it could also be due to maladjusted cables. Optimax engines are sensitive to plugs, if you don't know for certain when they were last replaced (recommendation is 100hrs or annually whichever comes first), you might consider that too.

[Mbrenegade]

The engine is mounted on a 2012 Tracker Pro Guide V175 Combo. The engine only has 44 hours on it and the plugs look to be original. I have picked up new ones to install but forgot my feeler gauge to set the gap. So that will happen next weekend. Will check for tension adjustment or misadjusted.

[JOE54]

becarful gapping those plugs feeler is really not a good way to do that need a wire gapping tool and no pressure on electrode pin or its ruined

[SilverFox579]

becarful gapping those plugs feeler is really not a good way to do that need a wire gapping tool and no pressure on electrode pin or its ruined

+1, wire gauge only and be sure to torque to 20ft lbs.

[Mbrenegade]

Thank you for the info!

[feather thrower]

Have an 08 115 Opti. Started with a 19 4 blade prop and it was too much. My 17 ft boat was very sluggish out of the hole. Swithched to 17 and it came alive. Hopefully you will have the same expericne.

[JOE54]

right prop makes all the diff

[Mbrenegade]

Finally was able to get a 13 x 17 spitfire prop and now the boat jumps up on plane in about 4 secs. Top speed on the Gps is 39.4 mph with the a rpm's at 5600. What a difference now the engine has no cavitation when turning anymore. Think she is dialed in now. Thanks for all in the info and advice on this issues. Happy boating and fishing!