Question about plugs

A

aqualug

Cadet
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Apr 3, 2005
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How bad is it on the engine to run on two different type of plugs? Both type are compatible with my engine, but I just realized that one of the plugs was a different plug type. I am not sure when this occured, but I am having a problem of dieing at idle and acceleration. Rebuilt the carbs and it definately seemed to help, but still has the problem at idle.<br /><br />Does anybody think that one plug being different could cause this? One of the gaps was off .010 as well.
 
D

Dhadley

Supreme Mariner
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Feb 4, 2001
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16,978
Re: Question about plugs

Depends on what motor it is and what plugs they are.
 
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aqualug

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Apr 3, 2005
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Re: Question about plugs

I do not have the manual in front of me, but I did look in it and 5 (78 CY?)of them are primary champions, and 1 (77CY?)of them is the alternate.<br /><br />I have a 1998 Johnson 200.
 
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Dhadley

Supreme Mariner
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Messages
16,978
Re: Question about plugs

Its probably the QL78YC and QL77JC4 plugs. Your looper can use either so youre OK. I would get them all the same though. I like the 77's in mine just because theyre a tad cooler. It should be fine with either.
 
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aqualug

Cadet
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Apr 3, 2005
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Re: Question about plugs

Would one spark plug off gap by .010 cause an idle problem?
 
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Dhadley

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Feb 4, 2001
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16,978
Re: Question about plugs

I doubt it. When you rebuilt those carbs did you soak the carb body and the throttle body?
 
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aqualug

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Apr 3, 2005
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Re: Question about plugs

I didn't soak it because everything I read said it could be bad for the metal housing. I did give it a thorough cleaning.<br /><br />I may have found my culprit tonight, but I haven't had a chance to get the boat in the water. I replaced the hose from the tank to the engine, along with all the filters. I did not take the valve going into the tank off. Well I did tonight and found a piece of Oak tree pollen caught in the valve. It was letting enough fuel through at WOT, but low speeds were giving me problems. It may not be the problem, but I am sure it didn't help the problem.
 
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Dhadley

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16,978
Re: Question about plugs

Youre right, that was a good find.<br /><br />Those carb and throttle bodys can be kinda fussy when it come to cleaning. The side plates have to be sealed good, those 2 tiny tubes have to be real clean, the emulsion tubes have to be perfect and theres tiny passages that have to be clean. Sometimes it can be a real pain.
 
A

aqualug

Cadet
Joined
Apr 3, 2005
Messages
9
Re: Question about plugs

I actually did it twice. The first time I did not replace the gaskets. When I still had the problem, I replaced the gaskets, and since I had them apart, I figured I may as well clean them again.<br /><br />I am really hoping I found the problem, but I am planning for worst case.<br /><br />From all of my reading, my next steps are to: <br /><br />do a proper lync and sync, <br />adjust the low speed valves, <br />then start looking for electrical problems<br /><br />My boat was sitting in Ft. Pierce during the last couple of Hurricanes. There is crud in every crack of that boat.
 
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