I'd have the dealer sort it out at 6 hours old.

Is the air screw on the carb wound in too far,wants to be about 1/1.5 turns out?.If not take it back,assuming the supplier is local enough 

1 minute ago, huski said:

Is the air screw on the carb wound in too far,wants to be about 1/1.5 turns out?.If not take it back,assuming the supplier is local enough 

Can't take her back. The dealer the other end of Aus. The carby's a Dell'Orto PHBL26s Standard setting for this one's 3-1/2 turns out.

If it's a carburettor model I'd be looking to see if the choke was sticking on....

Dell Orto carbs have a fuel adjustment screw, not air adjustment, screwing it in clockwise will weaken the fuel to air mix, the opposite to an air adjustment screw fitted to Kehein carbs. If it's a Gas Gas Pro I'm surprised it has a Dell Orto, Kehein have been fitted to UK models for a few years

I just checked in case I was thinking of another bike I had. It's not the GG Pro though, it's the GG 250 contact if that makes a difference. Sorry, should have said that earlier.

And a pic of the new plug after 15 minutes at medium throttle with new fuel at 100:1

I'll run another hour or so tomorrow and check again then.

 

Call Paul Arnott at the Hell Team - he'll sort you out.

Yes, I spoke to Paul earlier, a very helpful guy. Am doing as he suggested and will check the plug a bit later after dumping fuel and running 91 instead of 98 octane. 

Edited December 12, 20178 yr by studio208
typo

If you look at the outer metal portion of the plug, then that is likely to be the same build up of carbon on the cylinder head and piston...  Almost time for a de-coke.. !

If you changed to a hotter plug (higher number.) that would cure the central insulator carbon, but not the metal portion or head and piston.

Maybe the dealer has set the mixture very rich for running in, and might lean it up a bit on its first service.

.

ooops  Didn't see the second page, and new plug.

Edited December 12, 20178 yr by scifi

5 hours ago, sirdabalot said:

Dell Orto carbs have a fuel adjustment screw, not air adjustment, screwing it in clockwise will weaken the fuel to air mix, the opposite to an air adjustment screw fitted to Kehein carbs. If it's a Gas Gas Pro I'm surprised it has a Dell Orto, Kehein have been fitted to UK models for a few years

Dangerous do not follow!

Dell'Orto's can have either fuel or air screws,
- if it is a fuel screw it is mounted between the slide and the cylinder intake, (you screw in for leaner mixture and out for richer mixture)
- if the screw is mounted between the slide and the airbox then it is a an air screw, (you screw  out for leaner mixture and in for richer mixture)

But these are normally not effecting the plug so much.

Do a 15min. ride with the Task toi the engine to do something, very good is riding up hill or riding faster (over 50km/h), so the engine get really hot and especially the exhaust, do it for 15 minutes, then look at the plug again

4 hours ago, studio208 said:

running 91 instead of 98 octane. 

This IMO would be a backward step

The choke level on would be a nice explanation!

In that picture the lever is off - up would be on.

On 12/12/2017 at 11:31 AM, scifi said:

 

 

On 12/12/2017 at 11:31 AM, scifi said:

 

If you changed to a hotter plug (higher number.) that would cure the central insulator carbon, but not the metal portion or head and piston.

 

If its still an NGK, plugs that run hotter have a Lower number.

Edited December 14, 20178 yr by b40rt

Plug chop needs to be done. Engine hot not warm, ride along a flattish track or on the road at brisk acceleration 4th gear for at least 2/300 yards further if possible, the idea is to put the engine under a constant load making it do work. Pull the clutch in and at some time kill engine and keeping clutch in coast to a halt. Remove plug and check colour, rich tea biscuit colour is good, black is too rich fuel. Too much oil makes fuelling bad and reduces fuels ability to burn effectively. Has this bike been properly set-up by dealer or just unpacked and sold? Carb float level may need to checked. With a duff back and broken wrist I’d not ride until all is back to normal. Just running a two stroke and blipping the throttle is not good for bedding in rings and bearings. Some gentle road work will work wonders for bedding the rings and creating a better seal between cylinder and piston rings. Good way to burn off some of the crap that’s now lurking about in the exhaust. Hope you sort it ?