DJ or Dhadley

R

ReelDrag

Petty Officer 2nd Class
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Jul 12, 2002
Messages
143
In a recent thread titled "spark plug gap" you mentioned I may have another problem reguarding the plug gap on my 92 Johnson 115. I took it out and ran it yesterday with a new set of QL82C plugs gaped at .035. Ran ok, but it just doesn't sound right. Some, but not much WOT, lot of low speed zones. Pulled the plugs today to check them. 2 top plugs looked normal, light tan insulator. 2 bottom plugs, half the insulator was black, half tan. Are the bottom cylinders running rich? What would cause this?
 
D

DJ

Guest
Re: DJ or Dhadley

RD,<br /><br />How is your compression?<br /><br />Has it had a decarb recently.
 
R

ReelDrag

Petty Officer 2nd Class
Joined
Jul 12, 2002
Messages
143
Re: DJ or Dhadley

The powerhead is only 60 hrs old. Haven't checked the compression. Always used synthetic oil ,chevron gas. Decarbed at about 50 hrs. No loss of power that I can tell. Boat sat for about 4 months last winter. Thought I may be having a carb problem because of that. Maybe a bad float needle?
 
D

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: DJ or Dhadley

If you even suspect the carbs, I would go thru them and install OE kits.<br /><br />Your motor should run fine on the 77's or the 82's.<br /><br />What do you mean by "it didnt sound right"?
 
R

ReelDrag

Petty Officer 2nd Class
Joined
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Messages
143
Re: DJ or Dhadley

Kind of hard to explain, just didn't sound as smooth as it should. After experimenting with different plugs and octane fuel I've concluded that my motor runs best with QL77JC4 plugs gapped at .035 and 93 octane Chevron. I had tried the .040 gap and lower octane fuel after reading some of the threads on this forum. Took it out yesterday with the 93 octane and .035 plugs and it ran like a new motor. Higher octane fuel definetly makes a difference with this motor. No question about it... I'm still going to rebuild the carbs with oem kits because when I installed this powerhead I used the aftermarket kits and had a problem with the paper gaskets leaking. Maybe the needle and seats are garbage too. When I squeeze the primer bulb at idle it floods the motor. Don't know if this is normal or not.
 
D

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: DJ or Dhadley

Paper gaskets? What gaskets were paper?<br /><br />Squeezing the bulb should not flood the carbs unless a float is not leveled right, a needle is not seating or the primer is leaking by. We need to get this corrected. <br /><br />Just be careful using hi test fuel. Keep in mind it runs hotter (combustion-wise). Pistons can only stand so much combustion heat.
 
R

ReelDrag

Petty Officer 2nd Class
Joined
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Messages
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Re: DJ or Dhadley

The aftermarket kits had paper gaskets for the fuel bowls. Had to use the old rubber gaskets to get it to stop leaking.
 
D

DJ

Guest
Re: DJ or Dhadley

You should not need high test fuel. You will also make an octane junkie out of this thing.<br /><br />Is your timing correct? The high test fuel may be masking another issue.
 
R

ReelDrag

Petty Officer 2nd Class
Joined
Jul 12, 2002
Messages
143
Re: DJ or Dhadley

Timing is correct. What other issues could I have? I'm always open for suggestions.
 
D

DJ

Guest
Re: DJ or Dhadley

If it's running a bit lean, it will sound "tinny".
 
R

ReelDrag

Petty Officer 2nd Class
Joined
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Messages
143
Re: DJ or Dhadley

After looking at the plugs the bottom cylinders look to be running rich ( half the insulator black) top cylinders look normal ( light tan ).
 
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