Check out this plug

I am the farthest thing from a fueling guru and wanted to ask the experts on here of their opinion on my plug (pics below). I had warmed the bike with an older plug, put this new one in and rode fairly hard for around 5- 10 mins with throttle 3/4 to full, pulled in the clutch, killed the engine and coasted to a stop and removed this plug.

I have a 2001 BRP with stock air filter, airbox restrictor out and I have just added a Hindle slip on exhaust. All of my riding is 0-1000 ft and could be anywhere from 60F-90F.

In following with "the chart", I now have a 68s pilot jet, a 175 main the B53E needle is on the 3rd clip. Bike starts 1 or 2 kicks with the choke, Idles smooth and has gobs of power. When the throttle is twisted, it is like the devil himself is kicking you in the arse, wheeling easily in 3rd and even 4th. I don't feel any flat spots, and it seems to work bang on.

However, I wanted to see if the plugs are looking like they should as I just want to ensure I won't cause any harm to the engine/valves and that it is fueled close to where it should be.

Also, when I try to adjust the pilot (fuel) screw, nothing happens. The idle will change very slightly, but won't stall out or drop significantly as it is supposed to, only drops or raises about 100 rpm in turning the screw all the way in or almost out. I've checked the screw and it has no damage and all the parts are there. I'm thinking that this may be that the pilot jet is too rich, should I try a 68 or 65 pilot? Is it weird that the outer electrode is clean as a whistle?

Thanks
Looking forward to your thoughts (these are all the same plug, different angles)

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looks lean to me.... ?

Mine looked exactly the same , i think that is slightly on the lean side .

OK Thanks
I thought the electrode looked like it was lean too, but there is also that carbon ring around the bottom of the plug. The end of the new exhaust is kinda sooty too which points at richer??. I may try another notch down on the needle (to number 4) and/or possibly a 178 main jet to see what that does.

That is the problem , you can be rich on the pilot jet , lean on the needle jet and needle and then rich again on the main jet ( as a example ) , you need to find out where exactly you are on each throttle position , i had the exact same problem , lean in the mid in my case .

I would try the 70s pilot jet if i was you .

Mad Frosty wrote:I would try the 70s pilot jet if i was you .

Hmmm,
I had read somewhere that if the pilot screw did nothing when you turned it meant that it was letting in too much fuel and therefore the pilot circuit was too rich not lean?? That made me think that maybe I should lean the pilot and richen up the mid (needle) and/or the main jet.  
But again, I may be way off

I have the same carb setup you have and am around 600'elev. my bike has gobs of power but I have not checked my plug since last year she runs great starts 1st or 2nd kick idles fine! I will pull my plug and post some pics hard to tell if yours is running rich or lean maybe you should run your bike for a couple days and then check it!

JRZ7285 wrote:I have the same carb setup you have and am around 600'elev. my bike has gobs of power but I have not checked my plug since last year she runs great starts 1st or 2nd kick idles fine! I will pull my plug and post some pics hard to tell if yours is running rich or lean maybe you should run your bike for a couple days and then check it!

Thanks, Good idea, a longer running time might give me a better picture. Looking forward to your pics as a comparison too

Heres some pics of my plug sorry didn't take more but my phone wasn't zooming in for shit and I was ready to run it over with the pig!




Hope this helps wish the pics were a little better not sure if I need to change anthing as my bike runs great doesnt use any oil! fires up first or second kick and has tons of power you can feel her pull like a tractor, even in the summer I don't even choke it, I only choke it on the cooler days! plug is NGK-BKR7E11

I think Aurora did an informative write up on how to read your plug correctly on this forum some time ago I will have too look for it! You have a beautiful bike by the way love the black rims I was going to go gold on mine, wanted that retro 1987 Honda cr500 look but those black rims do look sharp!

Trailslapper wrote:

Mad Frosty wrote:I would try the 70s pilot jet if i was you .

Hmmm,
I had read somewhere that if the pilot screw did nothing when you turned it meant that it was letting in too much fuel and therefore the pilot circuit was too rich not lean?? That made me think that maybe I should lean the pilot and richen up the mid (needle) and/or the main jet.  
But again, I may be way off

That is correct , if you screw the fuell screw all the way in and it does not affect the iddle the pilot jet is too big , so it seems that you need to add more fuel in the middle range , ( nedle jet and jet needle teritory ) , perhaps lifting the needle one notch ?

Also you might need to run the bike for a bit longer than 15 minutes to get a proper plug reading .

If it starts easy,has a heap of power and no flat spots why bother to play with it,just leave it alone and enjoy the ride,you will drive yourself insane chasing the perfect carby setup.My bike has exactly same carby set up as yours,i ride at sea level manily, more than enough power to kill myself, i would not even dream of touching the jet settings, just start it and ride it.

Your absolutely right Beaver! even if my plug looks a little on the rich side im not going to touch anything it doesn't even pop when you let off the throttle! My plug has a nice uniform coffee color (dark roast )all the way down the electrode! So off I go for a nice Sunday ride!