# 115hp Mercury Hard to Start



## Radar (Sep 20, 2002)

I've been around outboards and boats my whole life and know them well. BUt we just added a boat to our collection that has a 1983 Mercury 115hp inline 6cyl. The motor runs awesome and is very powerful. However, getting it started is a big PITA. Have not quite figured out the trick yet. I guess these towers of power are known for being tough to cold start. Any suggestions for other "tower of power" owners? Must note that once it's started and warmed up, it fires right up after being turned off. You barely have to hit the key and fires nicely. As of current, we prime the bulb till very firm, push the key in to choke while cranking, then wait for it to at least bark. Then we keep cranking some more and messing with the idle speed until we finally get it to catch and begin idling. The chokes seem to be working as I can hear them click when i push the key in. Howerver this whole process seems to take forever. Is there an easier way, tricks, secrets?


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## Greenbush future (Sep 8, 2005)

_How many carbs are on that tower? trying to sync all of them is gonna be tough, have you de-carboned the engine and cleaned all the carbs out well-fuel system too? My guess is you know about Seafoam and the good results that can happen with regular use. Once it's running I would run a few cans through all those carbs, and dump a bunch in the gas tank too. If you can verify the chokes are all working, and still have issues, I'd pay to have it tuned by a specialist. If it has 6 carbs, that could be a bit challenging to sync. iboats.com has a nice Merc section, and a quick search will provide a bunch of other ideas. I had the same one years ago, weighed a dam ton, but it was a strong runner. _


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## limige (Sep 2, 2005)

I had one and it was hard on batteries with how long I had to crank it. I opted to bring some starting fluid and pop the front of the cover and give it a shot in a few carbs before I began cranking it. This drastically reduced crank time. I think its just such a big crankcase there's a lot of room inside.


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## Radar (Sep 20, 2002)

Yeah, I've only ran one tank though it so far, but that had a can of seafoam in it at least. It has 3 carbs that feed the 6 cylinders. Seems impossible to flood. It's pretty well tuned and cleaned. Was hoping someone might have a quick trick on cold starting it easier....in addition to the starter fluid suggestion.


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## brookie1 (Jan 26, 2011)

Try pumping the throttle while you are cranking it but be ready to back off the throttle when it starts so that you don't overrev it. And when it starts, keep touching the choke everytime it sounds like it is going to stall until it smooths out.


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## Greenbush future (Sep 8, 2005)

Radar said:


> Yeah, I've only ran one tank though it so far, but that had a can of seafoam in it at least. It has 3 carbs that feed the 6 cylinders. Seems impossible to flood. It's pretty well tuned and cleaned. Was hoping someone might have a quick trick on cold starting it easier....in addition to the starter fluid suggestion.


Really a bad idea to do this. The damage you could cause will negate any value. Like you said just figuring out how to start this thing, is your best bet, I would try to get it figured out w/o the fluid IMO.


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## 7iron (Feb 28, 2005)

#1 Never use "starting fluid"(ether) on an outboard.

Try this, with the motor in the water ready to go roll it over without the choke, grind it for just a second or two then hit the choke. Don't hold it long just a tunk.It may take a couple of bumps. I've got a 75hp Merc, I basically had the same problem.

If you feel you need starting help, my tech said to use a "spray carb cleaner" does the same as ether without the TNT explosion. Just a small (1/8 in) hole in the airbox is all it takes....Good luck


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## limige (Sep 2, 2005)

I've heard WD40 is a great alternative


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