howdy ya'll! what's up Bruce!

these plugs came out of my 240 today...I put nice NGK pre gapped plugs back in. Now to tune the Zthereapied carbs back to normal.

My brake booster went out and I had it rebuilt...but not before I had to drive it around with vacuum problems....trying to get it to run decently was an effort.... it wouldn't idle or run smoothly below 2000 rpm....

Others will probably have better input, but I'll take a shot. Since it's on the first 3 cylinders, I'd guess it's running to rich on that carb.

1) Check your choke on cylinders 1-3 to see if it's mis-adjusted / sticking w/ choke engaged. (most likely, since it's the first 3 cylinders).

2) Check mixture on carb for cyls 1-3.

3) Do a compression test to see if you have a valve issue, especially on #3. Only becuase it looks much worse.