How would you guys say these spark plugs look?

[sutor623]

Hey fellas,

Motor is '95 130 Rude. E1130TXAOR Looper. She runs great at cruise and upper RPMS. Sounds excellent too. I just did a fuel system overhaul (including onboard fuel tank) and want to make sure that my cylinders aren't running lean, so I decided to take a peek at the plugs.

Put about 5 hours on the motor, most of which were at 4200RPMs with a few minutes of WOT. I just wanted to get opinions on if these plugs look like they are burning properly. Plug diagnosis was never my specialty. Also, this being a dual headed motor, it looked to me like the port side plugs were running a bit hotter (they are a little more grey than the starboard side.)

Once again, just want to be sure that I dont have a lean condition.

Port Plugs:


Starboard Plugs:


Another pic of Starboard plugs:

 

[hunter200524]

The correct way to read plugs is to run WOT and kill the motor, then pull the plugs. You can't read them by just looking at them after running unless you are completely flooding out a cylinder or not running on it at all.

 

[F_R]

Personally, I would doubt anybody could truly diagnose a lean condition by looking at plugs unless it is already too late, and damage is done. Then you may see bits of melted pistons on the plugs. But that's just my opinion. Maybe somebody knows more than I do. BTW, that piston destruction can happen very quickly, once it begins.

 

[sutor623]

Personally, I would doubt anybody could truly diagnose a lean condition by looking at plugs unless it is already too late, and damage is done. Then you may see bits of melted pistons on the plugs. But that's just my opinion. Maybe somebody knows more than I do. BTW, that piston destruction can happen very quickly, once it begins.

Thanks fr. I think you are thinking more of a full or major fuel blockage. If gunk blocks up a port almost entirely then the motor won't stand a chance. But I have heard from quite a few mechanics that if the motor is running slightly lean, whether 2 or 4 strike, the plugs will look white and ashy.

And no, you don't have to pull the plugs immediately after. That is if you do a high speed shut down to check for water in the cylinder (cracked block)