hard starting merc

[sdculp]

I have a 50 hp mercury outboard which is 6 to 8 years old. I bought it used along with the boat 3 or 4 years ago. It runs fine and I am very satisfied with it, except that it has always been hard to start. My dealer/marina which does all my maintenance work and storage (not the same place I bought it initially) says it starts fine. I?ve discussed this with them each year and have them check it out, including plugs, but they still maintain it?s ok. I have to disagree with them, for the reason that the only time they start it is in shop conditions and not out in the real world. After being run for a while and then restarted, it starts immediately, but after standing for a half hour or so, or overnight, it is very hard to start.

After squeezing the fuel line bulb to make sure the fuel line is full, there are basically three ways to start the engine:
1. Turn the key until it starts. Forget this one!!
2. Turn the key, and after a second or two press it in to prime/choke the engine. Repeat if necessary. It sputters right off, but after much grinding it may or may not start. It acts like it has a very weak idle, but once started it idles ok.
3. The only real way to start it reliably is to advance the throttle and then use procedure 1 or 2.

There are times when it is really necessary to get the engine started in a hurry, and it just doesn?t seem that my engine is behaving normally. If it otherwise wasn?t just fine or if new ones weren?t so expensive I would trade it in. Is this the way I can expect a 50 hp Merc to operate?

 

[corm]

Re: hard starting merc

Hi,

I was hoping some one would reply to this for you.
Here is my take on your engine.
Non EFI engines are like cars from the 50 or 60's.
They need some gas peddle to start good. Your engine does not have an accelerator pump like the old cars so it needs some choke. You have to hold the choke button on for the choke to work on your outboard. That being said here is what happens when you shut your engine off. It builds heat inside the cowling because there is no water to cool it. Today gas is so full of aromatics that is evaporates out of your carbs just sitting there. So when you go to start your engine it does not have enough fuel in the carbs to operate correctly. You have to crank it over so the fuel pump can fill the carb bowls up ato the proper level and the vacuum can draw fuel into the crankcase where it is compressed and charges the combustion chamber when the intake port is opened. Where it is compressed and ignited. This is a simplified version.

How to start your engine without brain damage.
1. Prime the carbs with the primer bulb.
2. Advance the throttle.
3. Push in the choke and start turning you engine over. (how much choke is different for each engine so practice makes perfect on this)

4. Tricks.
a. Push the choke in as you turn off the engine. This causes a rich condition when you go to restart it. It will start better for the most part.
b. Enrichen the two idle needles 1/8 of a turn. (counter clockwise)
c. I use a 900CCA battery so the starter has all the amps it needs to spin the engine as fast as it can. (yes I know the starter does not need that much amperage but it works for me)
d. I advance the timing 2 degrees without opening the butterflys. (yes, I know the fuel today flashes different but it works for me)
e. I trim the engine vertical before starting. Tipped in out out decreases the efficiency of the carbs.

About starting the engine quickly. It only takes a heartbeat to advance the gas and choke while turning it over. Pumping the bulb takes a bit longer, but that only needs to be done after a hard run or overnight dockage. If you set your primer bulb so it is in the transom tray is is simple and takes no time. I train my passengers to do it unless I am closer like in my bass boat.

 

[sdculp]

Re: hard starting merc

Thanks a lot for your thorough reply. I was hoping for one like it.

It will be a few weeks until I get back in the water, but I am looking forward to trying out your suggestions. It looks as though I may have stumbled onto a bit of the solution by advancing the throttle.

I have a tendency to leave the motor a bit tipped because of the shallow water and hidden rocks in the Adirondack lakes, so that may be a major factor.

When the key is pushed in, is that a prime or choke---which? I know that if I leave it in too long---more than a few seconds--the motor tends to flood and when it does start there is much smoke and sputtering until it gets cleared out.

Thanks again.

Stu

 

[corm]

Re: hard starting merc

Hi,

We have some shallow shore line here in WI too. I just trim it p once it iis running.
You could have the tickle type choke on your engine. It is more
popular on the newer engines. The trick is figuring out how much is needed.
You can flood any of the carbed ones.
The throttle is a major key.