I have a 99 mercury outboard 2stroke. Had 3 spark plug. Is it normal that when you remove the spark plug, there are oil on the spark plug???is it from last year winterized? It does have black or look like burned gray spot in the center of the spark plug?? does have difficulty time start up sometime…..
sometime it start up right on first and 2nd crank…while other it take 4-6 crank or in advance throttle mode to start up.
let me know if it the spark plug problem?
No, there should not be oil on a spark plug. The ceramic should be a light tan and the electrode will show some signs of wear, but nothing should be coating the spark plug.
Look up online to see if you have the correct spark plugs for this engine.
Then I’d do a spark test on each cylinder. Finally, I’d check compression.
Obviously you should be running a high quality 2 stroke oil mixed to the correct ratio.
Grouse
Grouse
Buy new plugs. If the engine runs good fagetaboutit.
Pull the plug. Leave the plug wire attached. Try cranking the motor with the plug in your hand.
You’ll know whether the plug is good or not.
If your Merc is oil injected you will have some oil on them to a degree.
I have a Mercury also and I always change out new plugs every 2 years because I troll alot !
Cheap maintenance !
JMHO Jeff
Pull the plug. Leave the plug wire attached. Try cranking the motor with the plug in your hand.
You’ll know whether the plug is good or not.
Make sure to put the other hand on the block. You should feel a tingling sensation in the middle of your chest.
Just kidding. Do not try this!
If it was winterized, then yes it’s normal to have oil on the plugs. Replace them. It will cost you $20 or less. Some guys replace annually regardless, others every few years. Unless you put new plugs in last year go spend the $20 and follow suzuki’s advice above.
<div class=”d4p-bbt-quote-title”>lhprop1 wrote:</div>
Pull the plug. Leave the plug wire attached. Try cranking the motor with the plug in your hand.You’ll know whether the plug is good or not.
Make sure to put the other hand on the block. You should feel a tingling sensation in the middle of your chest.
Just kidding. Do not try this!
Are you guys trying to kill him?? Lol
Clean up the plugs and regap to specs and put them back in. I’ve never pulled a plug that did not have some sludge on it. Regapping will solve a lot of starting and rough idling issues. Get a spare set and have the tools needed to so a plug change on the water. A missing plug in a 3 cylinder should show up as a marked power loss. Otherwise as others have suggested, just replace them.
If its dry its good, if wet its bad re guardless of buildup or color.Color is an indication of fuel/air ratio.
I have a 99 mercury outboard 2stroke. Had 3 spark plug. Is it normal that when you remove the spark plug, there are oil on the spark plug???is it from last year winterized? It does have black or look like burned gray spot in the center of the spark plug?? does have difficulty time start up sometime…..
If your winterization process included fogging then the spark plugs will be fouled from the fogging oil. Run the engine for ~ 15 minutes to burn off the remaining fogging oil, then replace the plugs. This is standard procedure. The motor should start up like it did the previous fall, prior to winterization after you replace the plugs. Fogging always fouls plugs and the best step is to replace them.
Hope that helps
Thanks all
I will replace the spark plug…..just haven’t call my marina boat part see how much it cost…..
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