Help reading spark plugs (1 Viewer)

[Its me shaneus]

Have just put another new set of NGK plugs in my 2F. Engine runs ok but fouled a plug, too much idling and cold starting likely not helping. Has recently been upgraded to fitech efi and flame thrower 2 ignition and coil. Wires were new at that time ((NGK) as was cap and rotor.

Main thing i see is dark wet fouling on some and uneven white porcelain in a couple of plugs. Assuming oil fouling.

Any experts want to jump in and tell me if they think the uneven pattern points to valve stem seals? Hoping this is not rings as the engine was supposed to be low mileage rebuild by CCOT. It runs good enough and no blue tailpipe smoke. Can do compression test but have not yet.

Edit: they are wetter looking than photo really shows.

Plugs are 1-6 in image. #1 on the right.

 

[JohnnyC]

I would adjust the valves and timing then set out on a longer drive to then check the plugs

Imho I would also open the gap to 44 what are they set for now 31 or 39?

 

[charliemeyer007]

+1 for checking/setting valves and timing. I would also do dry/wet compression test with Marvel's MO and let it soak for a day in case there is any ring crud issue. Have any compression issues, you might whack the valves in the low cylinder with a lead hammer while it running to see if there was some issue with crud on seat face. Clean the plugs and go for a drive.

 

[Grayscale]

They probably just need cleaning more often. That and 5W-30 or 10W-30 will be easier for the rings to scavenge from the cylinder wall during the winter months. What viscosity of oils have been in this motor? How often is it changed? I've never seen a set of used Land Cruiser pistons that didn't have deposits in the ring areas. I've never looked down the barrel of a carburetor that didn't look like oil was vaporizing off of the hot intake valves, post shut-down. I'd say this set of spark plugs looks pretty normal, as all three of my F or 2F engines looked this way, not sure about a rebuilt motor though.

Is there obvious varnish on the dipstick, or varnish as seen by looking into the oil-fill hole?

Clean the plugs with a steel-wire toothbrush and some 200-grit sandpaper between the electrode and grounding strap. If fouling is causing incomplete burning of fuel, set the gap to the F-engine spec. .032-inch - air is an insulator just like polymerized hydrocarbons that are fouling the plugs.

 

[Its me shaneus]

Will dig in deeper Monday. Found the big issue was my tweek to add a little extra fuel to help cold starting in the efi settings. Went out and it about stranded me! Got to a gas station and took out extra fueling from efi and it ran good again for an afternoon of around town with a little highway thrown in.

Me and efi, a little like that monkey playing with the ak47 scaring everyone!