'12 back in action

[GMP]

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.

 

[Jakobi]

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!

 

[GMP]

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.

 

[mcnut]

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!

 

[MJC]

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 ?

 

[mcnut]

...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.

 

[GMP]

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.

 

[MJC]

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

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.

 

[socalgasgas]

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

 

[GMP]

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.

 

[Jakobi]

That would make sense to me. Explains why my ASII with non notced #7 needs to run so lean. Also noticed in the yamaha manuals that usa/canada always gets richer stock settings than the rest of the world.

 

[GMP]

I'm going to try and look at these carbs tomorrow. My NECF just came so Im curious how that will feel in position #4.

Another variable is possibly my cylinder. Its cast by S3, marked on the base. Smooth port finishes. I do not remember my other GGs being like this, but perhaps all the newer bikes are.

 

[Vindicator]

I'm going to try and look at these carbs tomorrow. My NECF just came so Im curious how that will feel in position #4.

Another variable is possibly my cylinder. Its cast by S3, marked on the base. Smooth port finishes. I do not remember my other GGs being like this, but perhaps all the newer bikes are.

I remember reading in a UK brochure that the '12s had an "improved Gilardoni cylinder" but how can one tell ?

 

[Cruiser]

Hey Glenn,, I may have an extra #7 slide from a air striker carb.. I'll check to see what it is in case you want to play around with some extra parts.. in fact I have a almost complete AS carb..

 

[Diggs345]

I remember reading in a UK brochure that the '12s had an "improved Gilardoni cylinder" but how can one tell ?

Send an email to gas gas uk , they are probably sick of me by now

 

[GMP]

Tried the NECF in #4. A little more torque, still nice and smooth. Looked at both carbs, the same as far as I can tell by what I could measure. Now, for the hell of it I put the #7 slide WITHOUT the notch in the '12 ASI carb, with the JD Blue in #3, basically the same jetting that I run in the '07 and have run in the '03. Guess what? The bike found its balls off the bottom! Runs just like the '07 now. That notch has a definite effect on the mixture off idle, more so than just the idle like many have said. This proves it in this carb anyway. The idle had to be readjusted as well as the airscrew but the bike pulls hard through the lower mid now like it never did.

So, in effect it was running like it had a leaner slide. You need fuel for torque, and all these real clean settings were not making it. Now it wheelies off the throttle like never before and the map switch works. The map change had no effect before because in the RPM range of the timing advance change, it was too lean to make more power anyway.

Now, why the hell does the factory just do s^&t like this? Someone is making some bad decisions. At least test, change, and document.

 

[Jakobi]

You don't think whatever carbs are available, an N1EF#2 with 40 and 175 is acceptable Glenn?

So what range you do feel the notch is affecting?? 0-1/4?? Sounds like the clip position only had a mild influence so I'm guessing below 1/4. In saying that the notch makes the slide feel one leaner, do you think you could achieve the same results running something like a N3EE, NOZE, or NEDE?

 

[GMP]

I guess my standards are higher.

It basically affects what the slide affects, up to about 1/4. There is no doubt in my mind that changing to the non-notched #7 added fuel and a significant torque increase in this off idle to 1/4 area. Before this, I always felt that I was fighting something trying to get that meaty low/mid pull out of the bike, something was not right. It was harder to wheelie over logs, now its just a half hearted twist and she's up. JD Blue is the richest dia I have tried. When I ordered the NED/NEC series the F dia was the richest listed on the Suzuki parts list.

I'm thinking of trying a #6.5 notched slide. The notch does give the bike a cleaner idle and better airscrew response, and may balance out close to the #7 based on todays results. Then I'll try and work up some settings with the NED/NEC series. With the right slide it should be easier to work up some good settings. I like the smooth power for some situations, but the JD Blue is great for most and the map switch tames it down a bit if needed. Really its about getting a power delivery I'm familiar with before racing for points next month.