Hey guys,

 

I just had my motor serviced and fuel pump/lines replaced less than a month ago. My issue is this: I get on the water, motor cranks perfectly fine and can be cut on and off all morning without issue. Then I go to make a run somewhere in the middle of the day and the motor won't crank. At first I thought battery was the issue as the livewell and graphs had been running all day, but voltage checked out ok. Now I'm thinking it sounds like it's not getting fuel. After about 20 attempts at cranking, she will finally sputter to a crank after holding the key in to crank for about 20 seconds. After that problem, I can make a run, turn her off, fish for awhile, then when I go to crank her again, she cranks fine for the remainder of the day. This has happened to me two weekends in a row (during tournaments nonetheless). In the middle of the day, she won't crank that one time, and every other time she cranks fine.

 

Motor is a 2001 Mercury 90hp 2 stroke.

 

Any ideas?

 

Thanks,

Steve

Won't crank, means motor does nothing, other than maybe click or something, the starter is not spinning the motor.

Won't start, means starter is spinning motor but the motor does not start, like it's not getting fuel or ignition or something.

Now, if it's not starting, I would check my fuel delivery system and primer (choke) first.

Sorry, I meant won't start. Choke seems to work as I always have to choke it first time starting it as she doesn't like to start cold. I can hear it click when I press choke in. 

Let me make a suggestion.  Hopefully you have someone with you the next time it does this, if so, with the key one, have them hold the choke/primer in and you squeeze the primer bulb a few times. Then see if it starts.  If that helps, for some reason the motor is not getting primed.  If that makes even worse, then it's probably being flooded, where maybe a carb needle is leaking by when sitting or the engine is getting what's refered to as heat soak.  Heat soak is where the heat of the engine makes all the gas evaporate when it sit's for a short time after a long run.   This will cause one to be extremely hard to restart after a long run or bog down when you start it and go full throttle to start off shortly after. 

Will do next time I'm out. I do believe the issue has occurred both times after long runs. If it is indeed heat soak, how can I fix this? I'm fairly new to boats and don't know my way around an outboard completely yet. Is this something that I will need to have done by a mechanic or something I could do myself with proper instructions?

 

Thanks for your help.

I had a problem with my 50 2stroke. Cold start at the beginning of the day, and then after it sat a while. Turned out being bad gas. Drained the tank, added quality additives.

Now she purrs and cranks first time after shes warm. But I make sure the motor is level, primer bulb is firm. If you trim up, all the gas can drain out of the carb bowl.

I don't think there is a real cure for it. Making sure the carbs a sync'd together and all the butterflies are fully closing will help. I had a 3.0L V-6 Johnson so bad about it, since I premixed my gas anyway, I finally installed an electric fuel pump. That way, all I had to do was hold the primer (choke) in for a couple of seconds and the electric fuel pump put enough fuel in it, it started as good as any DFI motor. Never had anymore problems after that.

I know what causes it, but have never understood why hundreds of motors just like it never have a problem and then one does.

Understand though, while I mentioned heat soak, there are lot of other things than can give the same symptom but are very much repairable. It could just be your primer valve is not letting fuel into the engine, while you are hearing the solenoid, doesn't mean fuel is going through.

There is also a little trick you can use by just cranking the motor a couple of seconds and stop, press and release the the primer, crank a couple more seconds, stop and press the primer again, doing this three or four times. Cranking let the fuel pressure build up, then you release it into the engine without the air mixing and evaporating part of it, giving a much richer prime. Again though, if the primer valve is putting fuel into the engine.

I had a problem with my 50 2stroke. Cold start at the beginning of the day, and then after it sat a while. Turned out being bad gas. Drained the tank, added quality additives.

Now she purrs and cranks first time after shes warm. But I make sure the motor is level, primer bulb is firm. If you trim up, all the gas can drain out of the carb bowl.

 

I thought about bad fuel, but that would mean two different stations two different weeks would have to have had bad fuel. I always use non-ethanol fuel with StarTron on every fillup. Primer bulb stays firm throughout the day now that the fuel pump has been replaced. Haven't trimmed when my issue occurs and it's always level.

 

BKeith, thanks. I'll try that startup tip next time I'm out.

 

As I was under the cowl today inspecting things visually, I noticed almost no oil had been used from last weekend. Normally, being a 2-stroke, I have to add fuel almost every time I go out. These past two weeks, I've made big runs and I had to add oil after the first week. Now, after this second week, the oil tank is still full. Not sure if this is a symptom, another issue, or just something I'm being paranoid about.