'12 back in action
 

OK its back in the woods after that unfortunate coolant loss incident and teardown. RB head mod, high flow alloy impeller/polished pump cover, new jetting, seat support, revalved forks.

I took a guess at the jetting:

45 pilot
NEDF #3
180 main
AS 1.25 turns

ASI with #7 notched slide

Pretty good! Bike is super linear, clean but not lean. It does not quite have the low end bark the other bike does, but its enough and super easy to ride. It will still lug down to 0 on a nasty hill climb and pull out clean, if your in more of a hurry a little clutch and revs make it explode. Its like everything is moved up the RPM range, upper mid is very strong and it revs to the moon. I have an NECF coming next week that has been on backorder, I'll compare that in #4 for a half clip richer change. A full clip on the NEDF is too much.

Not sure it contributes but the seat support I designed really opens up the air box by eliminating the battery box, and keeps the space between the edge of the seat and the plastic/subframe open so there is no question of airflow.

I could ride this bike with NO weight on the small 2K-2 flywheel, its that smooth.

Thats a huge main to run with that skinny little needle Glenn but its obvious your conditions call for that kind of juice. Lets hope that its all smiles from here on in!

It is what it is, and its not rich I assure you. It would seize with the jetting you run, I wouldn't even consider trying a W or J dia. based on the F dia which is about perfect. For some reason this carb/motor likes really rich specs, and I would like to find out why myself. I have to pull the carbs off both bikes and compare them in detail. I'm wondering if its something to do with the notched slide in the ASI carb body, as they seemed to show up in the ASIIs, and this bike seems to be a collection of random parts not a specified tested unit. There have also been different nozzle shield configurations over the years(standard, 1mm shorter, notched). This carb could be anything, who knows, and might be a lean runner with a lower signature with its combo of parts. It does respond excellent to air screw changes, and its not wasting fuel thats for sure. What I should do is just try the '07 carb with the JD Blue #3 and see if the bike runs like the '07, that would be a rough yes/no test if its the carb or not.

GasGas carburetors, they're like a box of chocolate, to quote Forrest Gump. You never know what you're gonna get.
AS1, AS2, I don't care. Just send me a new carb!

Your bike/carb is different for sure. Im about 150 miles north of you and there is no way I could run and H series needle in my bike let alone and G or F. That main is huge for an NExx needle. I run an NEDG in my 125, and an F was to Rich in that bike. I wonder what is so different about your 250 than mine and a lot of others ?

I can answer that. The carbs coming out of Spain have no standard. They throw together whatever is laying around, it seems.

MJC, you have the newer ASII carb that is known to run leaner jetting. I have a lot of experience with GG250s running the older carbs so that is my baseline, and this one is quite different from that baseline. I've had issues with this bike and I'm thinking my carb may be one of these as well. I have had the top end, intake, and primary of the motor completely apart, inspected, head modified, and reassembled. No air leaks, reeds good. Switched CDIs so I now have the '07 Kokusan in the '12, known good. My gut feeling tells me that the notched slide was never intended for the older carb, but its what GG had on hand. This might explain the low end jetting differences but not the appetite for the big main with the narrow needle. The notch is supposed to make the pilot ckt more sensitive, by increasing the velocity of air over the pilot hole, and not affect the other ckts. The newer carbs are shorter, so who can say with certainty that this dimmension is the same between carbs? It does jet like it has a leaner slide. Slide swap between bikes is easy, getting the carb out of the '07 concrete airboot without lifting the subframe maybe not so. I'm really glad I did not sell my old bike at this point.

Do you think the carbs are coming from Japan that way, maybe blowing out inventory,or problems getting inventory built up from last years disaster. Either way I can't believe GasGas thinks this exceptable. I've never heard of this happening on any of the major brands.

If it did come from Japan that way the little guys would get them not the big guys

I doubt that Keihin has any excess inventory to blow out, and very unlike the Japaneese to release a questionable product. The older carb hasn't been on a production GG in a few years, a KTM since '03, and Japaneese bikes before that. More likely it was sourced from somewhere else to meet production, just like the ignition. Spares, another company's overstock, worse, who knows? The big buyers of these carbs can specify changes as well. KTM one year had the nozzle shields cut down 1mm to lean the off idle area similar to a slide change. Not saying this is the case but if one were to source a number of spares like this, it would change everything. I guess I'll have figure it out myself, measue everything except the nozzle. I'm almost certain though that the notched slide did not exist before the PWK ASII. Ron at RBD might know I'm sure he has seen hundreds of these.