Ok, as some of you may know, I have been trying to find the culprit behind why my engine has a stutter at cruising speed with light throttle opening between 1500-1900 RPM. I have been playing around with the carb(jets and metering rods) because everything that I read and from what people have been telling me is that it is cause by a lean condition. So I have been going richer with the carb until now. I am at the richest most point on the calibration graph with this unit, and can't go any further. Next on my list was timing. I did some digging and found that I had the 2 lightest spings in the D and all of my advance (36 degrees) was in at 1700 RPM. I changed out one of the springs to a heavy silver and now all of my advance is in at 3000 RPM. The stutter is a little better, but still there none the less. I decided to pull out my plugs yesterday and have a look at them and I was kinda surprised at what I saw. No healthy tan/brown as you would expect, but not fuel fouled either-it's weird. I also noticed that as I was pulling out each individual spark plug, I noticed that they almost smelled like lighter fluid. Not sure what that means, but I would have figured that they would have smelled like gasoline??? I decided to take a picture of one of the plugs so you could see what I was talking about. don't worry about not being able to see all the plugs cause they all look the exact same. Lets see if they will load.......













Ok, so as of right now, these plugs have about 300 miles on them. They are the same plugs that I used to break the engine in although this is a full roller engine so I really don't think that any break in would wreck the plugs. As you can see, the ground strap electrode is gray. You can almost see what looks like soot on the 2 topmost threads of the spark plug. Now, I'm not exactly sure how to read these because I know that they are not a normal color BUT they don't like like they are fuel or carbon fouled at least when you compare them to pictures of spark plugs online. I am thinking about replacing them just for a little added insurance. Can anybody provide any insight? Thanks in advance!!

 

Whats the gap on those plugs? also clean them off with alittle gas and a wire brush. look for a blueish strip on the electrode near the bend. thats a way to indicate if the timing is right or not. if it's near the base it's advanced, and if it's near the tip it's retarded...that could be reversed i'm not sure. i'd replace them anyways, there cheap for the most part.

 

The ground strip looks ash white, like the heat line is right at the threads, too hot of a plug. That's my "off the top of my head" guess. That would explain why you're trying to richen it up and not getting anywhere.

http://www.dragstuff.com/techarticle...ead-plugs.html

I'd go to a timing curve that brings it all in at around 2600RPM or so, (1 light, 1 medium).

That link has some really good plug reading info on it, check that out.

 

i am posting on this thread because for some reason I cannot find the post on the main Tech/General engine forum. This thread is simply NOT THERE. I just wanted to let everyone know that so youdon't think that I am ignoring you. None of my posts are showing up at all...