Challenge: Wake Up The Mechanics - Outboard Challenge

[Brasshopper]

I see that this goes back to 2008, but you have some spark or you would not have the near start. Pull the cowl off, pull the wires off of the plugs, make the gap between the wire and the plug electrode about 1/2 inch more or less. Pull the cord. You should see a fat spark jump the gap and if you are lucky the engine may start. Why? You have just made a homemade spark gap sparkplug. The voltage has to become "hotter" to manage the 1/2" gap than it has to be to jump a .030" gap. So it ignores the path through the wet fouling that it is using and blasts across the gap.

Downside is that the larger gap may cause arcing in the coil or magneto secondary or whatever.

If this trick works, stop the engine and reattach the wires. Replace the spark plugs. Smelling the exhaust to see if it smells like gas might reveal if the gas circuit is working at all. Carb cleaning, as suggested above, is well right on.

[Gone2long]

Originally Posted by Ex-Calif

You've recently bought a used dink at a great price. It has a small 5.5hp 2 stroke outboard engine on it with a separate plastic fuel tank with associated black fuel hose, squeeze bulb etc. that plugs into a quick release on the front of the motor. It could be a yammie or tohatsu. It's your basic 2 stroke engine with fuel filters, magnetos, spark plug etc.

The previous owner claims it is 8 years old and has only been driven on Sundays by a little old lady in the slow lane going to church. In other words he claims low hours. He also claims that it runs great but, "once in a while she's stubborn and ya gotta choke 'er. I also had 'er serviced by Bob the mechanic 6 months ago." you putter around the bay for 30 minutes and decide that the price is fair so you make the deal.

You load her up on the trailer that Sunday and drive 500 miles north back home where she sits on the trailer until next Saturday when you splash her.

You choke her, and squeeze her fuel bulb, you pull the cord until your arm is about to come off but she won't start. You get an almost start sometimes but she won't catch. You remember that when you started her yourself last weekend the engine cover was already warm. You also remember blue smoke but can't recall if it was excesive or just normal like other dinks you've driven. It's also a little colder 500 miles north.

OK mechanics and wanna bees.

What are the logical and complete troubleshooting steps?

You stole my post : ). This is almost the exact situation I am in at the moment, except, the exhaust did not look too bad.

Thanks for saving my fingers the extra exercise. Great to hear all the various takes.

G2L

[jldunn86]

Originally Posted by David M

Start with the basics first. If you kept pulling the pull start after you got a sputter then you flooded the engine. Put the choke back in.

X2 and hold the throttle open ( with no choke ) until it stops stuttering..

[Gone2long]

Originally Posted by Roy M

This was the FIRST Lesson we learned in Outboard Motor Repair: 1. Change the plug. 2. Place the motor in a water tank or in the water. 3. Remove the cowling. 4. Spray Quicksilver Power Tune into the carburetor. 5. Wait 15 minutes, then attempt to start. 6. When the engine catches, spray most of the can into the carburetor, SLOWLY, and stay clear of the big cloud of smoke. 7. When the motor is running with less smoke, empty the remainder of the can into the carb to stall it. 8. Fire the motor up fifteen minutes after the stall. Stay clear of the dense smoke. 9. Start the engine, enjoy the dramatic change. 10. Repeat, once a season.

It's the dirty little secret of outboard repair. It cleans the crap out and the motor sounds like a sewing machine, again. Then, don't tell anyone and collect lots of loot from frustrated boaters.

Roy,

Great tip, but abroad, where I am, we can't get such stuff. I am wondering if something similar (but not exactly the same) can be done with 3M carburetor cleaner.

I know that this stuff has either or something dangerous, which is highly explosive, so we are not going to shoot whole cans of it into the carburetor, right? : )

But, could 3M be used as a cleaner without having to pull the entire carb apart and cleaning each part separately before re-assembly?

We have all probably used it to "jump start" an old jeep, but will it work to start a gummy outboard, and, if so, can a few repeated tries (or some other trick) be used to actually clean up the carb without pulling it apart?

Pardon my ignorance on the subject, but engines have never been my forte.

Thanks for your insights,

G2L

[Gone2long]

Originally Posted by Sunspot Baby

Spark:

Since she almost starts, you probably have spark but it is easy enough to check.

Fuel/Air mixture: Will she start with a little starting fluid sprayed into the carb? If so you have definitely nailed it as a fuel/air problem.

After checking all the simple things it could come down to bad fuel (yes it does go bad) and/or a gummed up carb.

The most frequent problem I have on my 2 stroke is a bad fuel hose. I always carry a new one as a spare.

When you kill the engine to store it for a while, disconnect the fuel hose and let the engine run until she dies. That reduces carburetor gumming.

If it is a gummed up carb, spraying something into the carb will not clean needle and seat problems. Luckily, these little carbs are easy to disassemble, clean, and reassemble. Get a carb kit from your friendly local outboard shop.

George

Yeah, I have heard your idea from at least one VERY experienced outboard mechanic, who suggested running the engine dry if you don't intend to run it for more than a couple of days. Apparently, idle fuel takes very little time to gum up carb jets.

Please chime in as per my question above regarding the potential uses of Carb cleaner to start a gummed engine.

G2L

[Gone2long]

Originally Posted by Ex-Calif

Sully, had the main areas to look at first.

Roy had a good troubleshooting methodology and donradcliffe, although a little late to the party had a nice concise list of things to check.

The example was hypothetical.

The key is to be organized and thorough in your troubleshooting.

I chased a coil problem in my Jeep Cherokee for about 6 weeks and about $900 bucks. I changed the coil first along with spark plug wires, plugs etc. The thing would run a day and then quit when hot. Cool it off and it would start again. I eventually changed the main computer with an aftermarket one for about $600. Same problem.

I went back and started again. The second time I changed the coil it solved. The new coil I bought was bad from the factory and would generate an open in the primary winding when hot - sometimes. I found it by carrying my meter around and checking it when the thing quit and before it cooled off.

Had the same problem on my 1979 Datsun pickup. But, luckily, there was no computer to change, so changing the coil and adjusting the timing and spark gap, solved my problem. Probably cost me $900 in my own labor, of course, but I learned at least as much as I am learning from this thread ; )

Good stuff,

G2L

[Therapy]

Gone2long,

Maybe you have seen/could find Seafoam.


Smokes a lot like the other description.
Cleans out gunk so engine can run again.

Basically wet the inside parts, let soak, burn off (run engine). Repeat.

[Gone2long]

Originally Posted by Therapy

Gone2long,

Maybe you have seen/could find Seafoam.


Smokes a lot like the other description.
Cleans out gunk so engine can run again.

Basically wet the inside parts, let soak, burn off (run engine). Repeat.

Yes, saw it up the thread and am looking into getting a friend to bring us some. None where I am at the moment.

Thanks,

G2L