Holley/Demon Carb stumble
View attachment 1715549771 View attachment 1715549772
so i was able to come up with a couple new plugs
so i cut the other one up as well.
left is #1 and right is cyl 2
You are still rich everywhere. I look at the porcelain in thirds. The top third (this is a very loose measure...sometimes it’s not quite equal thirds...so the more you cut apart plugs the more you’ll learn to discern what you are looking at more accurately) is idle and just off idle. You can get screwed up looking at this part of the plug if you are a throttle blipped or you have relatively big squirters or worse...both. The pump shot can make that part of the plug look fat when it’s not. It’s the throttle blippers that feel the need to whack the throttle 6, 7, 10 times to “clean it out” when in reality they are dumping a crap load of fuel into the engine.
The middle third is T slot and cruise which depending on gearing and tire size can also be on the main jet, and most likely will be showing both T slot and main jet. Learning how to tell what you’re looking at takes time and reading as many plugs as you can, and just looking at them close and observing what it’s telling you. Also, there are some great plug reading articles out there, so reading them is a big help. I read them often so I don’t get set in my ways of looking at plugs, because when you do, you can fool yourself.
The bottom third (or a bit less in many cases) is WOT. If you are picking the fly poop out of the pepper, you can get the fuel ring down to .080-.100 wide. And none of this is set in stone either. If you keep trimming the fuel ring at WOT down and the car looses MPH, then you need to give it what it wants, to a point. If your car has a higher MPH with a wider fuel ring, then give it to it, unless it’s as wide as yours. That has to be about .250 wide or more and that is just too wide. If it’s faster with that tune, something else is wrong.