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5hp mercury outboard

Ugly pumpkin

Ugly pumpkin

Well-known member
Joined
May 19, 2020
Member Number
243
Messages
1,081
Loc
Port Huron, Michigan
Some years ago I ended up with my great uncles 16' aluminum boat. It has sat and I have mowed around it.
I mention to a friend that I need to do something about it. He shows up at my house with this motor. :rasta:
$200 and it's all mine.
It has spark. Carb is getting fuel.(leaks at every seal)
Has some amount of compression. (Will get an actual test soon) Doesn't chooch with go juice down the carb. Gave a little pop with juice directly into the cylinder.
Fix it and pay the man?
Dump it on his porch?
Kill it with fire?
Bacon?

TLDR I Know nothing about 2 strokes. I am a retard about boat stuff.
Who knows about small outboard merc motors?

Ps. I like fishing and happen to live near a big ass lake so a boat would be good for that stuff.
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Plenty of compression. Get a carb kit and maybe a coil. Should be good to go for under a $100. As long as they put oil in the gas those things are damn near unkillable.
 
Stuck said:
Plenty of compression. Get a carb kit and maybe a coil. Should be good to go for under a $100. As long as they put oil in the gas those things are damn near unkillable.
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I'm trying to keep this a cheap project. Not looking to throw parts at it. Is $200 a decent price for this fucker? Are they that so finicky about a/f ratio to not pop off on a snort of ether?
 
So I give it a snort of go juice and a couple yanks and it does nothing. I sit for a few minutes and then give her a yank and she almost started. Fuel line disconnect the whole time. Thoughts?
 
Connect the fuel line and try again? Easily worth $200 if its in good shape even if you have to put $100 in it, new ones are $1600.

I just reread. If it has spark rebuild the carb and run that sucker. If you were closer Id give you a grand for the boat and motor.
 
Rebuild the carb. They are easy and don’t take long. Rebuild kits are cheap. I’ve played with a few outboards, and one thing I’ve found is if there are any leaks in the carb or fuel lines they don’t like to run.

That has good compression, so as long as your getting spark it will run with the carb rebuild.

When you try to start it make sure it’s in a bucket of water. I use a 30 gallon trash can to test run my motors. Make sure it’s pumping water as soon as it starts, otherwise it will overheat quickly and you’ll blow it up.

if it ran that would be a 400-600$ motor, so 200 plus some time and a little more money would be worth it.
 
On a 2 stroke the air/fuel have to travel through the crankcase. So it takes longer for it to get to the combustion chamber.
That might be why you let it sit and then it starts.

Clean the carb, make sure the passages are clean, blow air and carb cleaner through them. No need for a kit unless the gaskets are all junk.

Another common problem, (besides improper fuel ratio) is the crank case filling up with fluids, as in carb flooding them. If that happens, then there is less space during each stroke. Meaning there is less vacuum to draw fuel and air.
Get a manual, or google if there is a drain on it and make sure it is drained. A case with fluid in it will also throw off your air/fuel ratio.

Ditto on running it in a barrel of water. It only takes seconds to destroy a water pump and tuning it will be much closer to real life applications.

These motors, actually anything with carbs can have quirks. Find that quirk and it will start every time. Sometimes it is full choke, some don't like choke. Some like half throttle, some like full throttle, some like no throttle.
 
Yep, pull that carb apart, clean it real good and run it. Then sell/trade it and get a 9.9 (or bigger), that 5hp would be more of a trolling motor for a 16' boat .... :laughing:
 
Tech Tim said:
Yep, pull that carb apart, clean it real good and run it. Then sell/trade it and get a 9.9 (or bigger), that 5hp would be more of a trolling motor for a 16' boat .... :laughing:
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I had an old 3 horse on my 14’ deep v. 5 mph everywhere, but it got me there. Now I have a 9.9 and it’s actually fun taking the boat out. I second getting a 9.9. The 5 horse will get you there but it’s not gonna be quick, and you’ll be plowing the water instead of planing out on it
 
Ugly pumpkin said:
I have it a 5 gal bucket. Is that enough water?
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Yes. Keep the run times short,(the water heats up pretty quick) and submerge the lower unit as much as you can into the bucket. If you don’t see a pee sized stream of water coming out of the motor in the first 5 seconds shut it off.
 
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replace the rubber water pump impeller now.

before it fails and the motor overheats and leaves you stranded on the water.

yearly maintenance.
 
Ugly pumpkin said:
Where should I be ordering parts from?
I know fuckall about boat stuff.
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I usually find the part number of what I’m looking for then shop around online for it. For hard to find stuff I start calling around to the real old local places, some of them have nos parts that can’t be found elsewhere
 
Well, got it off and apart. Amazon has a OE gasket set for $150, knock off set for $30. Knock off carb is $80, OE is $250. Thoughts? Hard carb parts look good. Leaning toward cheap gasket set and a new spark plug.
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87manche said:
replace the rubber water pump impeller now.

before it fails and the motor overheats and leaves you stranded on the water.

yearly maintenance.
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This sounds good. Besides the impeller, what else do I need to buy for this job?
Looks like Amazon has a kit for about $40. Sound about right?
What type of oil does the lower unit take?
 
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my much larger outboard has an impeller and a wear plate to be replaced.

lower unit gets filled from the bottom with gear oil.
 
I use quicksilver lower unit gear oil. Served me well over the years. Always fill from The drain hole, until it comes out the fill hole. I know it sounds ass backwards but it ensures the unit is full and devoid of air.

typically when I rebuild carbs I just replace the gaskets, as long as there is no sign of wear or damage on the hard parts. A good initial setting for the jet is 1 full turn out from fully seated, then adjust at idle till it isles good. Fine tune once on the boat and in the water.

edit: often times if the gaskets seem decent when you took them apart and nothing tore removing it, I will put it back together with the original stuff and test to see if it will run that way. If it does, great, but still order the rebuild kit.
usually on the smaller units it’s only the impeller itself that needs to be replaced
 
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Ugly pumpkin said:
80w-90 good for the bottom end?
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Die hards will tell you it must be marine oil because it handles moisture better or some crap.

I use a synthetic 75w-90 and it is running fine. Just check it from time to time or drain it every fall, refill in the spring to keep any water out.
If you ever find water in it, better figure out how it got in there and fix it.
 
Ugly pumpkin said:
Carb gasket kit, spark plug, fuel filter and impeller kit are ordered. 80w-90 good for the bottom end?
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I only use marine grade gear oil for the lower unit. I may be considered a die hard though.

And if you search the model number of your motor the specs should be available on what weight oil to use and quantity.
 
I haven't had any luck finding specs for it.
If anyone can find me some info I'd appreciate it.
S/N: 0A820780
Model (I think): 4 ML 1004137
THANKS!
 
Tiha said:
Die hards will tell you it must be marine oil because it handles moisture better or some crap.

I use a synthetic 75w-90 and it is running fine. Just check it from time to time or drain it every fall, refill in the spring to keep any water out.
If you ever find water in it, better figure out how it got in there and fix it.
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if there's yellow metal parts in there the sulfur in a GL-5 oil will attack them.

there's brass bushings and shit in my old johnson. So I use the marine shit.
 
87manche said:
if there's yellow metal parts in there the sulfur in a GL-5 oil will attack them.

there's brass bushings and shit in my old johnson. So I use the marine shit.
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I thought about that too. We'll see what's in there when I get it apart. Parts should start arriving this weekend. Maybe I'll tear apart the bottom end this weekend.
 
Got the parts in. Carb kit, water pump kit, spark plug with spares and fuel filter. Also got one of those fancy green mats for the work bench that dude on utube uses so this job should be a breeze. :rasta:
Going to rebuild carb today and see if she'll run, then dig into the bottom end.

Questions:
initial setting for idle mixture screw? I'm thinking all the way in and back out 1 turn.
spark plug gap? Somewhere on the internet said .040 which sounds good to me.
Thoughts? Comments?
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