plugtest photo

[maxco]

I wanted some opinions. This is WOT plug test on a 2000 Mountain max. BR9Ecs plug on 30 deg day.This looks like a happy plug to me. All the plugs looked like this. I seem to not be very good at my analysis. Nice cardboard color electrode, carboard all around the porcelain, dark on the outside, the first 3 threads look dry, but there is oil all the way to the top. I have read the posts about plug test, but the art and subtlety of it seems to elude me Thoughts? Thanks

 

[SXlover]

I'm no expert on reading plugs by any means, and pictures always are hard to tell by, but with that said they do look OK. If that was my sled I'd maybe want them a little bit darker than that but ONLY because I also ride them at -20 as well. I'm also used to running BR9ES, not sure if that would cause a difference at all.

Again, I'm not an expert at all on reading plugs, I just know the basics. There is many more knowledgeable people than me on this site that will hopefully chime in.

 

[mrviper700]

looks spot on for that temp, so when it gets colder youll be lean then. I cant blow up the pic to see good but the center core electrode looks to be silver right across the end of it, that means your spot on for that temp. Also the ground strap looks to be the same color all the way to the housing of the plug, if you had a little room to spare for temp drop youll get a little differnt color about half way back on the strap and the center core will be silver around edge with a slightly darker center. Likely gonna need another size up on the main if you ran it for a good long run wide open, would need to be at least a 800-1000ft, for colder temps.

I would look into the needle settings as thats where alot of problems come into hand, do a mid throttle run and see what they look like and post.

 

[maxco]

plug run

I did do a 3/4 throttle run, though I did not get a picture. They were black and wet completely. Oily/wet all the way across the whole plug no difference in color.
I was going to drop the needles a notch. I really did not see silver across the electrode. The light was bright. They were pretty consistently cardboard.

 

[maxco]

Another photo

Here is another WOT photo.

 

[maxco]

ignorant question

Sooo I have been playing with the jetting. The machine runs well. My question is you tune to the book and then to the piston? It may be a shortsighted question, but I am not a mechanic.
I set the jetting where SLP,The manual, and input on this site guided me to. That was a good starting point. I am rich at cool temperatures 20 deg avg.
I recently dropped the jetting down to 140 across the board.
My manual says that the clutch side should be set a little richer.
My plug testing has consistently shown the PTO to be pig rich. So I have been slowly leaning it up, as testing is indicating.
I guess here is the crux. The manual says PTO should run hotter. Reality is telling me that PTO seems to be running cooler than the other cylinders. Do I follow that thought?Or am I missing something?
This cylinder is always black and wet looking when I pull the plug. What is going on?

Thanks for any and all input

 

[sleddineinar]

I have the same thing going on with my PTO. It even fouled out once last weekend. I run CPR pipes. I'm thinking of changing my nozzle out to be the same on the pto as it is on the other 2 cyls. I have been told that the pto nozzle is fatter than the center and mag. You can look up the parts and see that the numbers are different. I would go a size bigger on your main jet if you plan on running at colder temps.