Two Stroke Outboard Help

[thinkxingu]

Hi All!
Some of you may remember another forum member gifting my son an aluminum rowboat last year (the year before?!). Along with the dinghy was a 7HP two-stroke Mercury outboard and fuel tank.
I'm not all that mechanically inclined, but I'd like to maybe get it going for L'il Buddy since he's been doing so well with the trolling setup.
Can someone summarize, or point me to a resource that shows, what I'll need to do?
My questions, more specifically: 1. What should I replace before trying (other than fresh fuel)? 2. What do I do with the oil/mix? 3. How does the tank connect? 4. Starting procedure? (I noticed there's a priming bulb). 5. Controls? (They look simple, but I just want to be sure). 6. Finally, we have oars—would the best/easiest approach be to put it in the water or find a bucket?

Thanks!

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[JTA]

Bucket. Get the motor running.

[Hillcountry]

I have some spare 55 gallon drums. You are welcome to one if you like...couple of clamps and a 2x4 and you have a way to work on the motor out of the water. I’m sure someone has made one on YouTube...google it!

[8gv]

Check your PM's.

[AC2717]

trash barrel and a piece of wood will work on that size motor.

As stated above need motor info, but i for one:
bottle of sea foam, some starter fluid just to give the carb a sniff from the outside.

fuel/oil mix will depend on serial number.

change the plug (cross with serial number of motor to make sure right one and gap)

and start pulling

[thinkxingu]

Ok, so it's a 7.5 as Top-Water indicated. Pics attached. The previous owner who gifted the motor to my son has messaged me, and L'il Buddy is currently finishing a neighbor's landscaping job, which will give him the money to get what he needs for it, so we're moving forward!

If anyone has a site to share that would have mix, spark plug, etc. info I'd be grateful.

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[thinkxingu]

Originally Posted by Top-Water

Mercury / Merc 75 from about 1976 Takes takes the newer more common fuel connector.

I think you can get a new tank and primer bulb from wal-mart for about $75.00 (just bought all this stuff a few weeks ago.) If the motor has not been used in a while it is going to more than likely need a carb rebuild and a water pump. However if it was used recently .... and had treated fuel in it ....... it might start with fresh fuel. (Don't forget to have the fuel vent open on the tank.)

This is where you have to start. If the original metal tank has any rust in it not worth trying to fix.

Spec's

Thanks, Top. It's a fairly new plastic tank, so that's good. The previous owner said he'd run it out of gas when finishing for the season, and he's never had a problem starting it again in spring, so I'm hoping the carb is good.

What mix do I need to use? My plan is to throw it on the boat with some fresh fuel and see how it goes.

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[Garcia]

As the former owner, that's what I would do - get some gas, bolt it on, and see what happens.

Good luck!

[thinkxingu]

Grabbing the fuel and oil tomorrow. Does octane level matter? I run super in all my 2-stroke garden machines but don't know about the outboard.

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[MAXUM]

Think the oil/fuel mixture is 50:1 , octane doesn't really matter in a motor like that - not like this is a high performance high compression engine.

I'd also consider putting some seafoam in the first tank of gas, if there is any crud in the fuel system that will clean it out good.

Wouldn't replace a thing unless there is a need to.

[thinkxingu]

No go this morning after fresh fuel/oil/Seafoam. First thing to check? The primer bulb was filling, and it appeared to be getting fuel, so I'm thinking a spark plug and maybe a little starting fluid?

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[ishoot308]

This...^^^^^^^^^^^^^^^^^^

[thinkxingu]

Soooo, it appears that someone here in my camp knows motors. We tried some starting fluid and it didn't "pop," so I'm heading out to grab a couple plugs as these look dark and oily.

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[ishoot308]

Originally Posted by thinkxingu

Soooo, it appears that someone here in my camp knows motors. We tried some starting fluid and it didn't "pop," so I'm heading out to grab a couple plugs as these look dark and oily.

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Check for spark before you do anything else...if there’s no spark new Plugs are not going to help...

Dan

[thinkxingu]

Originally Posted by Top-Water

As we pause for a parts run ...... a few messages from our sponsor.

Hahaha! I didn't have an 11/16" socket to pull the plugs to check for spark, so I had to run to Aubuchon. On the way, my son and I discussed options, and he decided $12 was reasonable to start with fresh plugs. On our way home with both!

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[8gv]

If no spark is observed...

Does it have a kill switch that is off?

I believe that vintage did not have a lanyard switch.

The switch is likely a spring loaded push button aka a momentary switch.

It grounds the primary wire for the coil.

A failure here is unlikely but not impossible.

To test this you can remove the wires from the back of the switch and keep them separate from each other and the metal chassis.

That will exclude the switch.

[Garcia]

Originally Posted by 8gv

If no spark is observed...

Does it have a kill switch that is off?

I believe that vintage did not have a lanyard switch.

The switch is likely a spring loaded push button aka a momentary switch.

It grounds the primary wire for the coil.

A failure here is unlikely but not impossible.

To test this you can remove the wires from the back of the switch and keep them separate from each other and the metal chassis.

That will exclude the switch.

There is not a lanyard kill switch. There is a button to push to stop the engine. The most recent registration sticker on the boat will indicate when the motor last ran - my guess is 2017 but I’m not positive. I have no idea when the plugs were last changed; my guess is a long time ago.

[8gv]

But...

When you get it going, beware of the “second run” syndrome.

When a carburetor has hardened deposits from fuel that has broken down during storage the first run can sometimes be pretty good.

This leads the operator to assume he got away with not cleaning the carb.

Days later, on the second run, the gas in the carb loosens these deposits and they find their way to small passages and the motor quits... five miles out!

So the moral to the story is...

Don’t trust it for a while!

(Or just do a complete carb job in the first place)

[thinkxingu]

Originally Posted by 8gv

But...

When you get it going, beware of the “second run” syndrome.

When a carburetor has hardened deposits from fuel that has broken down during storage the first run can sometimes be pretty good.

This leads the operator to assume he got away with not cleaning the carb.

Days later, on the second run, the gas in the carb loosens these deposits and they find their way to small passages and the motor quits... five miles out!

So the moral to the story is...

Don’t trust it for a while!

(Or just do a complete carb job in the first place)

This exact thing happened with a snowblower a friend bought used a few years back...only he was in the middle of his driveway, not in the middle of a lake!

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[thinkxingu]

Ok, so we're getting spark (and a couple shocks!). I pulled it over about a dozen times and pulled the plugs and they were dry—not getting fuel or need to pull more?

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[Poor Richard]

Is there a fuel shut off valve somewhere?

Hate to say it but I think you're diving into the carbs on this one.

[thinkxingu]

Originally Posted by Poor Richard

Is there a fuel shut off valve somewhere?

Hate to say it but I think you're diving into the carbs on this one.

No fuel shut-off.
The sun has pulled overhead, so motor work has been paused for now.

Step #2, getting fuel to the system, will have to wait until after 4.

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[ursa minor]

Originally Posted by Poor Richard

Is there a fuel shut off valve somewhere?

Hate to say it but I think you're diving into the carbs on this one.

Little Mercury’s like that (or even the big ones of that vintage) don’t have fuel shut offs built in. They often have a fuel filter under the cowl and screens on the carburetors (one carburetor on this one) so check those. Also, all the ones I had have a diaphragm type fuel pump that uses crankcase pulsation to move the fuel. As mentioned above, the diaphragms take a set with age and rip sometimes. Easy rebuild with the right parts. If you’ve got spark and compression the third piece is fuel. You’re close!

[Diver Down]

Just buy some "motor muffs" for 10 bucks on Amazon. You attach them to the lower unit and a garden hose and your good to run the motor as long as you want. Or you can fill a garbage can full of water!

[thinkxingu]

Updates to come today...

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[thinkxingu]

Before I post any further, a word of thanks to forum member Garcia, who gifted the vessel and outboard to my son, and 8gv, who spent the morning showing me and L'il Buddy how two-stroke engines work.

Webmaster, I hope you find solace from the criticisms in THESE types of connections.

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[thinkxingu]

It's ALIVE!!!
https://youtu.be/eax0OH3rifg

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[JEEPONLY]

A kid's dream!

So, what did it?

[Garcia]

Originally Posted by thinkxingu

It's ALIVE!!!
https://youtu.be/eax0OH3rifg

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That’s great! If he has 1/10 the fun I and my kids had with it, he’ll have a lifetime of memories.

[thinkxingu]

Originally Posted by JEEPONLY

A kid's dream!

So, what did it?

It was a stuck needle thingy in the bowl doohickey. Everything else seemed tight, and we used it for over an hour today, including to Blanchard Island to wait out the rain!

8gv took us step-by-step through troubleshooting, which was pretty awesome.

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[Cal Coon]

Originally Posted by thinkxingu

It was a stuck needle thingy in the bowl doohickey. Everything else seemed tight, and we used it for over an hour today, including to Blanchard Island to wait out the rain!

8gv took us step-by-step through troubleshooting, which was pretty awesome.

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Keep startron fuel stabilizer in the fuel at all times and you will most likely never have a problem with the carb getting gummed up again, IMHO.

[JEEPONLY]

Originally Posted by thinkxingu

It was a stuck needle thingy in the bowl doohickey. Everything else seemed tight, and we used it for over an hour today, including to Blanchard Island to wait out the rain!

8gv took us step-by-step through troubleshooting, which was pretty awesome.

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As Think mentioned in post #38- this blows the criticisms away!

Glad is wasn't the farfignewton (urban dictionary)!