Priming an outboard... basic questions

[convergent]

I have had the outboard boat in my signature for several months now and just want to understand if I'm doing everything correct in starting it when cold. I am wondering if I'm priming it correctly. It usually takes several attempts to get it going and sometimes longer than others. Once its been running for 30 seconds, I can restart it all day without an issue.

As an example, I go out boating after I was out the prior day. I haven't been priming it at all in that scenario. If its been a while, then I do hit the build 2 or 3 times. Is it OK to prime when the motor is still tilted back in the travel position? I figured that wouldn't be good, so don't do it.

So I put the motor down and turn the ignition switch to start it turning over. I wait about 2-3 seconds and then push it in for choke for about a second and then release it. I may have to do that twice. So after about 6-7 seconds of turning over it usually fires and runs for a couple of seconds. If I don't push up the fast idle, it will shut off. If I do try to push up the fast idle it usually also shuts off most of the time. Its very sensitive at this point. If it doesn't get going right away, I usually try 2-3 more times and it might fire and shut off, or it might not fire. I wait a little bit and try it again. I don't think I've ever tried to crank it more than 10-12 time before it cranks, and its usually once I can get the fast idle moved up a bit without it stalling that it starts running. Once its runs for about 10 seconds I can move the fast idle down and it runs fine for the day, no matter how many times I shut it off and restart it.

I am wondering if this is a normal outboard starting scenario, or if I should be able to get it to pretty much start on the first try every time. I'm new to outboards, so the whole bulb thing is a new concept. Should I be priming it more than 2-3 times before trying to start it very time? How do you know when to stop priming?

Beyond the priming, is there something else I'm missing here? Its not been a bad experience so far, but I just want to make sure that I'm doing it right.

Thanks for the help.

 

[Barnacle_Bill]

Re: Priming an outboard... basic questions

Pump the primer bulb until firm, turn the key on and push in and hold for 10 sec, start the motor and continue to bump the key in until the motor is running smoothly. You may not need the full 10 sec or may need a little longer. Just experiment until you find the right amount.

 

[mhg]

Re: Priming an outboard... basic questions

Each engine is a seperate animal and will respond differantly
It sounds as if you need to push in the key to choke (enrichen) it more
As the engine first starts to turn over push in 2 or 3 seconds and release while still turning over. when it fires and wants to die push in on the switch without turning to start and this should keep the engine from dieing. You can continue to use the choke as needed with the high idle lever until it warms enough to run on it's own.
Mike

 

[starcraft1982]

Re: Priming an outboard... basic questions

would be somewhat helpful to confirm what outboard youve got but im assuming its a mercury from your descriptions.mine is the same way.first start can be(is) rough.after that i can stop/start all day w/no issues.i am learning older mercs(mine is a 1988)need lots of gas for that first start.my sequence is prime bulb(w/engine level),push choke in,turn key just for a second or two,prime bulb again choke and crank.will fire up.get the fast idle lever up and let her warm up.i have NEVER flooded this motor w/too much gas.my dads evinrude wouldnt start for a month after giving it that much gas!anyway,youll figure it out,what it likes,with time.mine is also pretty touchy about how its tilted in starting cold.doesnt matter after initial start.hope this helps.also check the bulb tightness when you do above steps.i can prime it to fairly firm and get nothing till i choke,start,etc.then when i prime after the steps,it gets MUCH firmer and then starts.mnaybe just mine,maybe not.just my experience.good luck.

 

[rodbolt]

Re: Priming an outboard... basic questions

dunno, a 115 merc was built EFI,carbed,primer system,choke system and in a 2 stroke and 4 stroke configuration.
dunno what you have other than its 115 HP.
so any advice is a poke in the dark.

 

[convergent]

Re: Priming an outboard... basic questions

Its a '93 115 Merc, so its carbed and oil injected. Sorry I didn't mention that, but figured the signature covered it.

So on the priming part, I should keep priming until the bulb gets firm? I wasn't doing that all the time, so that may have been part of the problem. And I was only choking it for a couple of seconds and then releasing the choke before, or once it started to fire. Sounds like I need to hold the choke in after its running for a couple of seconds.

Now that you mention it, that makes sense. Ever lawn mower, chain saw, weed wacker, etc. I've ever owned you have to turn the choke on and leave it on until its running and then slowly turn the choke off. I just wasn't thinking of it that way since it was an instantaneous (push in) choke button. I will try choking it longer next time out.

Do you lift the fast idle lever up before you start it, or after its running? I'm leaving it down and then trying to lift it up after its running and thats where its stalling.

Overall this hasn't been that bad at all, but my 18 year old son made the observation yesterday that it seemed like each time we went out with the boat that it was taking a little longer to get it started than the last. Part of that is that I'm trying different things, but I think he's right to some extent. The last time was more because we hadn't been out in almost two weeks, and prior outings hadn't been more than 2-3 days since the last outing.

Thanks again for all the suggestions.

 

[rodbolt]

Re: Priming an outboard... basic questions

trim engine to full down,pump fuel primer bulb to fill the carbs.
make sure engine has sufficient cooling water. raise warm up lever.
turn the key on,push in fuel primer switch.
start engine while holding fuel primer switch in. once engine starts release key and primer.
sometimes you have to bump the primer switch occasionally as engine is warming up.
you really want that engine to light up at about 1500 RPM or so.
your engine does NOT have a choke.
it has a fuel primer system that injects gas behind the throttle shutter when the system is activated.
just because the hull is a 93 model has no bearig on the engine, repowers happen.

 

[sasto]

Re: Priming an outboard... basic questions

Seeing how your problem is getting worse it sounds like you need a tune-up. Try some new plugs first. You are getting some good advice from others though.

 

[Flyvet]

Re: Priming an outboard... basic questions

My 97 Johnson 150hp Oceanrunner, carbed engine starts with about a 2 or 3 second push on the key. Any longer and it tends to flood.

 

[rodbolt]

Re: Priming an outboard... basic questions

97 OMC150 also has quick start, a feature NOT found on the 93 115 merc.

 

[convergent]

Re: Priming an outboard... basic questions

trim engine to full down,pump fuel primer bulb to fill the carbs.
make sure engine has sufficient cooling water. raise warm up lever.
turn the key on,push in fuel primer switch.
start engine while holding fuel primer switch in. once engine starts release key and primer.
sometimes you have to bump the primer switch occasionally as engine is warming up.
you really want that engine to light up at about 1500 RPM or so.
your engine does NOT have a choke.
it has a fuel primer system that injects gas behind the throttle shutter when the system is activated.
just because the hull is a 93 model has no bearig on the engine, repowers happen.

I'm pretty sure the engine is original ('93) because the boat had been in the family of the person that sold it to me for most of its life, and they were pretty open about the history of the boat.

Thanks for the info about the fuel primer. The prior owner, and most people discussing it on the forum her keep referring to it as a choke. So if it injects fuel... how exactly does that work? I know that a choke is a butterfly that closes off air to increase the concentration of fuel in the fuel/air mixture. Sounds like the primer does the opposite.

So does holding in the key to engage the primer continue to inject fuel in, or is it a one injection per press kind of thing? Should I repeatedly push and release the key while cranking and after it is running, or do I just keep it held in while cranking and after its running. Hopefully my question makes sense.

It would also seem that this wouldn't do anything unless the bulb was properly primed, vs. a choke which is going to work independently from the fuel situation (sort of).

 

[Barnacle_Bill]

Re: Priming an outboard... basic questions

As long as you hold the key in the enrichner will continue to squirt fuel in the carbs. Unlike OMC motors those old mercs are very hard to flood.

 

[saumon]

Re: Priming an outboard... basic questions

Thanks for the info about the fuel primer. The prior owner, and most people discussing it on the forum her keep referring to it as a choke. So if it injects fuel... how exactly does that work? I know that a choke is a butterfly that closes off air to increase the concentration of fuel in the fuel/air mixture. Sounds like the primer does the opposite.

So does holding in the key to engage the primer continue to inject fuel in, or is it a one injection per press kind of thing? Should I repeatedly push and release the key while cranking and after it is running, or do I just keep it held in while cranking and after its running. Hopefully my question makes sense.

It would also seem that this wouldn't do anything unless the bulb was properly primed, vs. a choke which is going to work independently from the fuel situation (sort of).

The manually activated enrichener system is a very simple one: it take fuel/oil mix from the top carb bowl and dump it right into the crankcase (it's gravity fed). To test it, disconnect the line that goes to the crankcase and activate it through the elec. switch on the remote control (push on key) or manually by pressing the push switch under the enrichener (it's a 2 inch cylinder located behind the throttle linkage), you should see fuel/oil mix flowing. It is continous and work as long as there's fuel/oil mix in the top carb bowl.

Hope it help.

 

[convergent]

Re: Priming an outboard... basic questions

Thanks guys... this help me understand what is going on. I was very worried about flooding and it looks like I need to err more on that side of things. Headed to the lake in about 10 minutes and will give it a try.

 

[convergent]

Re: Priming an outboard... basic questions

I went back out yesterday and was a little heavier on the primer bulb and the primer switch and she was running on the second turn of the key... so definitely a lot better than past outings. Thanks everyone.

 

[convergent]

Re: Priming an outboard... basic questions

I thought I'd give another update on this in case anyone else is struggling with this same thing. The last three days I've gone out I was able to get the old 115HP to start on the first turn of the key. I'm hitting the bulb 4 or 5 times until its really firm first. Then I turn the key and let it crank for about 5-6 seconds and then start repeatedly pushing in and releasing the key. About 5 or so push and releases and it fires and runs smooth. I don't know that its even required, but I can push up the fast idle lever slightly then and I have left it there for about 5 seconds and then pushed it down and all was good. It doesn't stutter and all and not even a hint that its going to stall.

Prior to this thread and getting your help, it was a lot more effort to get it going. This makes me think that pushing the key and releasing it gives a squirt of fuel each time, and that holding it just does it once. I may be wrong on that, but its night and day different now starting it.