Mercury 4HP - some questions from a new owner

[Beware_of_Dawg]

Hi everyone! New here... I have a few questions and hope to get some advice/guidance.

I purchased a used 4HP mercury outboard. I was told by the previous owner that it hadn't been run in awhile but worked perfectly. I have no reason not to believe that as he is a neighbor who also offered to give my $$$ back if I was dis satisfied.

The engine is spotless. It's not brandnew, I suspect it's somewhere between 5-10 years old. I don't have the serial numbers with me right now.

I was told by someone else that I should go a little heavy on the oil/gas ratio the first time I ran it.

So it wouldn't fire initially, I changed the plug out and it fired up after a few pulls.. idles a little rough (shakes a little although I have it lossely mounted to a large plastic trashcan filled with water and Im not positive what "normal" is as far as the idle shake). I let it idle for a few minutes, revved it up pretty high a few times (initially it did bog down when I punched the gas, perhaps not warm enough? Again, Im not sure if this is normal)

Because I was advised to run heavier on the oil mix initially she smoked pretty bad but fired up easily the next couple times. I'm eager to get it out on the water (12 foot john boat) and do some fishing. Last night I started it up, it fired on the first pull but stalled out and now it won't fire up at all. I thought perhaps I flooded it, so I let it sit for an hour and tried again... nothing?. I did the same thing again this morning, and nothing it wont fire at all.

I'm fairly sure it could use a carb cleaning, are there any instructions you guys can offer on that? Would spray cleaner do the job? or can someone instruct me as far as what could be the issue and if a "full clean" of the carb clean can be done fairly easily myself or should I seek a professional to tune it up before I attempt to put it on the water? How much should that be? I have a big fishing trip planned for tomorrow morning and hoped to get it out there...

Any advice, or guidance for a new / outboard ignorant owner would really be appreciated!

Thanks for everything in advance

David

 

[Silvertip]

Re: Mercury 4HP - some questions from a new owner

You are making assumptions about the issue and not "troubleshooting". Since you changed the plug previously and it started, don't you think it would be a good idea to pull it and see if it is dry (no fuel) or wet (flooded). And leaving an engine sit is not a cure for flooding.
If the plug is wet, the engine is either getting too much fuel or there is no spark. Make sure you have the throttle control set to START so the kill circuit is not activated. Check for spark using a spark tester or hold the shell of the plug against metal and pull the cord. You should see spark jump the gap. If there is spark and the plug is wet, there is too much fuel. With the plug removed, pull the engine over several times to expel the excess fuel. Insert a GOOD plug and try again. Your starting procedure may be flawed as well. You use the choke on a cold start, but not a hot start. How "heavy" did you go on the fuel/oil mix?

 

[Beware_of_Dawg]

Re: Mercury 4HP - some questions from a new owner

You are making assumptions about the issue and not "troubleshooting". Since you changed the plug previously and it started, don't you think it would be a good idea to pull it and see if it is dry (no fuel) or wet (flooded). And leaving an engine sit is not a cure for flooding.
If the plug is wet, the engine is either getting too much fuel or there is no spark. Make sure you have the throttle control set to START so the kill circuit is not activated. Check for spark using a spark tester or hold the shell of the plug against metal and pull the cord. You should see spark jump the gap. If there is spark and the plug is wet, there is too much fuel. With the plug removed, pull the engine over several times to expel the excess fuel. Insert a GOOD plug and try again. Your starting procedure may be flawed as well. You use the choke on a cold start, but not a hot start. How "heavy" did you go on the fuel/oil mix?

Recommended was 50:1, I went roughly 40:1

Inside the trashcan around the rim/top of water there was significant oil residue despite only running it for a few minutes. Again, I have no idea what "normal" is. As I mentioned, this is the first motor I have ever owned and don't have the benefit of a friend or someone with experience to draw on. That's why I'm here, hoping for some education. Thank you for the pointers, I'm listening and I'm likely going to go home at lunchtime while the engine is in front of me and walk through your advice with my ipad or phone in hand to post here...

You mentioned having the throttle it in 'starting' position. There are no labels that indicate what that is. There is an arrow on the throttle handle itself, and another on the housing.. If that's "starting position" that's how I had them lined up.

Thanks again, I appreciate it.

 

[Beware_of_Dawg]

Re: Mercury 4HP - some questions from a new owner

I was only using half choke & choke on the cold start attempts.

per google it, recommended starting procedure is

1. connect fuel line
2. pump the primer bulb once and once only !
3. move the throttle into the start position
4. ensure the gear is in neutral ( middle position )
5. flick the carb switch open
6. Pull the pull start

1. Assuming that refers to an external tank, this one is internal.
2. there is no primer bulb
3. didn't see anything on the motor itself which indicates what that is.
4. yes
5. referring to choke?
6. yes

Thanks for being patient with me on this, if I had someone here in front of me I'd get all this in a matter of a few minutes and wouldn't have to ask all these stupid questions. lol.