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Having a bit of a hard time getting the carb set up correctly on my 2009 CRF250R.
Plug looks lean to me? http://s39.photobucket.com/albums/e180/ ... 2012%2013/
50-60 degrees F, 30-50 % humidity at sea level.
Pilot circuit is rich - fuel screw all the way in and not changing idle?
I know "on the stand" is not a proper way to diagnose but it spits fire at WOT.
While riding it feels pretty good, not much noticeable popping but I don't bounce off the rev limiter much.
Bog is still there once in a while. Bike has around 15hrs, valves are spot on and everything is stock
other than Loud Mouth and Dyno Jet Stage 1 kit which is 185 main, 48 pilot, clip 4th from the top.
Also did O-ring mod and put in a 55 leak. Burning Sunoco Standard Purple(110 leaded).

When jetting was stock 185 main, 42 pilot, 70 leak. Plug still looked lean and had some decel pop and standard off idle bog.

Also maybe considering going to a 37mm carb.

B64 wrote: Burning Sunoco Standard (110 leaded).

What bike is it that you are running leaded fuel?

2009 CRF250R

by the looks of you pics looks like you might running more on the rich side then lean since you plug looks kinda wet and dark/black in color. i run vp 110 in my 05 crf450r with a jd jet kit 185 main 45 slow and needle clip position 5. my plugs are alway a light brown/ tan color which from what i have read should be the ideal plug color.

Leaded fuel is no good for iridium spark plugs.
If you have used it for a while it will eventuallly short the plug out.

The photos seem to show a grey centre electrode that would suggest lean. It could be how this fuel burns as well. The outer shell looks black and normal.

Should I run a different plug? I think I will at least replace it.
Maybe raise the needle one position?

Always only make one change at a time.
I would move the needle clip up on first and see how that goes.

You should run the plug for your year and model.

What was the reasoning for running the 110 octane fuel?
Do you have ahigh compression piston fitted?

I was under the understanding that it would be cleaner burning and more consistent and maybe the lead would add some extra lubrication.
After looking into it some more it looks like I am somewhat misinformed. I think I will try 50/50 or just strait 91 pump.

it should run an iridium plug stock i know my 450 uses an irridium plug

also i have been running race gas vp110 in my bike with an irridium plug and have had no issues with the plug

der_berger,
Lead contamination is what harms platinum and iridium plugs.
Is VP110 a leaded fuel?
How high is your compression?
How do your plugs look?

yes vp110 is a leaded non oxygenated fuel.
i usually run strait race gas most if the time because lately the pump gas around where i live in san diego sucks.
my bike bike is an 05 crf450r the motor is basically all stock except i have the TRX valves installed
compression is i believe 12:1
i havent check my plug in a little while but the last time i checked it was a light brown color

Higher octane makes less power, unless you are detonating so badly without it that your bike isn't running well.

It is really tough to make any conclusions from plug reading with modern fuels. it is possible with race gas, but not on the stand.

So what is a good fuel or combo of fuels to run that will offer better consistency and cleaner burning than strait pump? I am in CA and only have up to 91 at the pump.

These bikes are designed by some pretty smart engineers to run on premium pump gas at sea level.

If you are absolutely committed to monkeying with success, mix in 25% race gas. It will make your exhaust smell better.