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Discussion Starter · #1 ·
I have a 1997 3.3 Johnson that I run for a weekend and its fine then the next weekend it won't get any spark. I usually swap out the spark plug and it goes. I have a feeling something is leaking oil on the the spark plug swamping it. When i pull it out there a bit of oil on it. Should it have some oil or none at all? Any help is appreciated.
 

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Hinterhoeller HR28
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4-stroke OB's should have clean plugs. 2-strokes will have some unburned fuel/oil residue.

If the motor is running too cold (say if thermostat is stuck open), it will foul plugs prematurely.

There's a good Johnson/Evinrude forum on iBoats as well.
 

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2 or 4 stroke?
 

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My 2 stroke lawnboy mower used to do this. The mixure was running too rich. I went down to a 32:1 ratio and it solved the issue. Mix the exact amount Johnson recomends and try that.
 

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I had the same problem on my 1990 Evinrude 9.9 (two stroke), and can confirm the richness theory. I now painstakingly measure out 50:1 as per owner's manual and haven't had any starting problems.

Do you use one of those marked-out jars that is graduated for different ratios? The graduations are labeled according to the amount of gas you're adding; you fill to the appropriate graduation with oil, add some gas, swish around, and transfer to the tank. No more converting fiftieths of a gallon to ounces or whatever :)
 

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If the plug is a year old I'd replace it.

If the gas is over 2 months old I'd replace it.

When mixing small amounts of fuel I recommend getting a couple of small plastic bottles and filling them with the correct amount of oil for 1/2 gal or 1 gal (mark them with a perm. marker)then just pour it into a plastic can and add the correct amt of gas.

Almost any motorcycle shop or dealership parts department can supply you with a "RATIO RITE" measuring cup.

RATIO-RITE CUP from Aircraft Spruce
 

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Are you using HIGH OCTANE gas? Do you know that the higher the octane #, the less volatile the fuel is? I have seen it a thousand times, guy thinks premium fuel will give more power, spends more on gas, and his motor doesn't have the compression required to run on premium. Plugs are always fouled, hard to start, no power, etc. Many 2 stroke oils are designed to run at 50:1 , many provide sufficient lubrication for 2 strokes at this ratio. Read the labels.
 

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My 8hp Yahama runs 100 to 1, it's an 1987.:eek:
 

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First I would lean out the fuel mix a little, if you're not happy with that then run a slighty hotter plug, if that didn't help I would do the top end job, with a service manual it would pretty simple and might even be fun for ya
 

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Another thing you might check is the reed valve, it sits between the Carb and cylinder, if it's gummed up or has any nicks, crack or chips, it needs replacing
 

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Discussion Starter · #12 ·
hey everyone...well, yes i've done everything above.
i odn't run the high grade. i run the mdeium grade fuel that johnson and most marine mechanichs' recommend.

I also have one of those extra bottles that measures out exactly the 50:1 oil ratio.

i called a local outboard repair shop here and they said something about the seals in the chamber possibly being loose and getting oil to the spark plug. but at $140 an hour i'm hesitent to take it in for repairs.

any help would be appreciated.
 

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You don't kill the motor by pulling out the choke do you?

Do you forget to take off the choke after starting?

Does this motor have an oil injection tank?

Change to a motorcycle 2 stroke oil and use the same mixing ratio.

Check that you are using the correct heat range plug.

I DON'T RECCOMMEND THIS BUT MANNY DO----
when stopping the motor shut off the fuel first and let the motor die by running out of gas.

I would be very wary of this shop----:rolleyes:
hey everyone...well
i called a local outboard repair shop here and they said something about the seals in the chamber possibly being loose and getting oil to the spark plug. but at $140 an hour i'm hesitent to take it in for repairs.

any help would be appreciated.
 

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Mix the fuel at no more than 50 to one, and use NO fuel additives. Fuel additives contain ethanol, which combines with the oil and emulsifies it with any moisture in your fuel, there is always some, and gumms up the works. Also don't use ethanol mixed fuel, gasohol or such, only pure gasoline. New clean fuel, no additives and a quality 2cycle oil at no richer than 50 to one. If you still have a problem, you have a problem.
 

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Discussion Starter · #15 ·
i'll check the reed valve.
any other suggestions for parts that have gone bad?
as far as emptying out the bowl...i usually do that. Generally when i get back to shore I hit the kill switch. then i'll turn the fuel line off and then start the motor again and let the fuel run out since I don't use the motor during the week and it has to be transported in my car on its side to my storage unit and I don't want any leakage.
 
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