What is the standard (emissions) jetting as new ?

[stay_upright]

In the UK (not sure about the U.S.) the GG's arrive with and emissions jetting which is quite lean.

However I believe these bikes run cleanly off the bottom.

I believe the slide is a no 9 but what needle, needle position, main, pilot and airscrew position are used. This is for a 05 300 EC

I think in my jetting fellting I have ended up with something close to this jetting at low throttle openings however the bike is now running too hot and boils too easily although throttle response is very nice from low down. - see my other post i want to check the impeller as well.

My next question is why is this jetting changed immediately for something that is far richer? To keep the engine cool or more torque? But I suspect these have to be at the expense of a lot more 4 stroking at low throttle openings?

[Eric K]

I had a stock Euro '06 EC300 imported to the US on special order. It came with a lean Euro set up and a performance set up.

The Euro emissions jetting on my '06 EC300 was crazy lean #9 slide and a CHN needle. This was designed to work with the black catalyst pipe (BE250326001H) and the restrictors. The catalyst pipe chokes it up and runs hot.

For performance...

Get a non-catalyst pipe (GasGas silver BE250326001 or equivalent)
Remove the airbox and powervalve restrictors (if installed).
Try a #7 slide, CCK needle and 40 or 42 pilot.

[stay_upright]

My bike had the 'performance jetting' which had more than enough power however ran rough at low RPM's this is due to 4 stroking and would require a steady speed of 30mph or more on tarmac before it would run clean.

I really dislike 4 stroking and would prefer to buy a 250 four stroke than have a 2 stroke that 4 strokes most of the time when i am using it (most of my speed trail riding racing is probably less than 30mph).

So I leaned off the bottom end but had to run a 9 slide 35 pilot (I think) and this weekend had to drop the standard needle to it's lowest point in order to combat the 4 stroking. Previously it ran fine with the needle in it's middle clip - needle I think is the performance on but something like N1EF (or N***) anyway it's nearly 2 years since I checked it I think. Main is pretty big 178 or 180 I think - I don't want to touch that if I can help it as I'm a lot more worried about WOT being too lean than the bottom end.

I'm worried this jetting is too lean to be healthy for the motor and as a minimum will change the needle back to middle clip and go smaller on the pliot so from 1/4 throttle up is is not lean.

Bike is non-catalyst GG OE pipe basically had the standard performance set-up before I got it.

Only 1 other thing my compression has always been low at 150 but I changed the rings and it remained the same so I think it would be more base gaskets but since it ran so nice last year I haven't done anything about it....

[Eric K]

The N1xx series triple taper needles do not work very well at sustained low throttle openings. Single taper needles work much better. Start with the simple changes - try a #7 slide, CCK needle and 40 or 42 pilot. This works quite well for low speed operation.

Report back on how that works.

[cdn280]

My euro spec 2006 300 came with both pipes, a GG (nickel plated? one) on the bike with a 180 main installed. I'm currently using the 178 that came with it and the LTR needle. Its never 4 stroked and has only done the loaded up coughing the first time you go thru 1st and 2nd gears from cold. In fact, I've ridden in single track all day breaking trail at barely above idle and it never does the typical 2T cleanout coughing. A bit smokey after all the idling, but thats it.
The other jetting that came with it was a #6 slide, a 115 ! main, and a CHM (could be CHN) needle.

[ferguscawley]

Guys

Where are you buyng your needles from ?. I see suggestions to try this needle, try that needle etc. Where are these needles available ?.

Did a quick seasrch on line but found nothing obvious. (Saying that, I couldn't find beer in a brewery)

Thanks

fergus

[stay_upright]

CDN what's your pilot temps and elevation then?

Interesting you said it has never 4 strokes, most 2 strokes do this so in a way it's unusual that yours doesn't. If it's not 4 stroking I wonder why it's smokey after idling. I think the smoke comes from the 4 stroking leaving a lot of unburnt oil in the cylinder/pipe... Still I wish I had your bike, or mine as it was running last year...

Eric sorry to keep picking your brains but how does the CCK differ from the N1EF. Interestingly I was looking at the Kehlin website and they were showing (I think) the needle diameter has the largest effect on jetting around where I'm trying to get it right and that the pilot jet is only affecting idle and just off idle where's I thought the pilot jet was around 1/4 throttle. I believe it's around 1/4 throttle I need to concentrate on though I may mark the throttle and check exactly where I want to target.

I will definitely try to get hold of a CCK and try that set-up I have the 7 slide from the previous set-up. Is the CCK a standard Kehlin needle or some-one else's OEM needle? It would be nice to be able to easily find info in the diameters/tapers etc and be able to move up or down a needle size in necessary.

Thanks for the replies so far!

[skid jackson]

Some one want to describe what 4 stroking sounds like ona 2t?? I don't know if i would know if my bike was doing it!

I ride mostly tight woods avg speed 16 to 18mph

I was running a 45 pilot, #7 slide, cck needle at middle slot, 178 main. The bike seemed rich off idle. Spooge on pipe and plug always looked wet so I changed the pilot to a 42, air screw 1.5 turns out.

Ran that the last few times out and now it seems a tad lean off idle. was thinking about putting the 45 back in. What can I do to richen up the 42?? someone suggested raising the needle one clip.

If I decide to put the 45 back in, what can I do to lean out the 45??

[stay_upright]

I believe the 4 stroking produces spooge since every misfire you are putting a cylinders worth of oil down the exhaust and it's gotta come out somewhere.

Listen to your bike idle, imagine a smooth humming (constant tone like a sewing machine) the 'roughness', cackle, louder pops are all misfires - this is the bike 4 stroking.

Now ride along a flat road at say 10mph and slowly keep opening the throttle until you notice a change in the engine note probably somewhere around 1/8 to 1/4 throttle - that change is going from 4 stroking to firing every revolution (no misfire).

A wet plug is a good sign of quite a bit of 4 stroking - again the large amount of misfiring means there is a lot of unburnt oil which will stick to the plug and can often foul them (why 2 strokes foul plugs).

It's not always the case though that eliminating this is best for everyone though reading through the forum here most people look for a clean crisp jetting with little/no spooge which tells me people here don't like 4 stroking however I think top riders jet to encourage this for a softer throttle response in tight conditions.

My experience though is that if it is nearly eliminated then the power on my KTM 200 or this GG 300 is down compared to stock jetting but smooth and linear and will never foul plugs and uses significantly less fuel to the point where 3 hour races i do not need to refuel though of course now I have overheating problems but didn't last year with jetting that eliminated this....

[Eric K]

Originally Posted by stay_upright

Eric sorry to keep picking your brains but how does the CCK differ from the N1EF. Interestingly I was looking at the Kehlin website and they were showing (I think) the needle diameter has the largest effect on jetting around where I'm trying to get it right and that the pilot jet is only affecting idle and just off idle where's I thought the pilot jet was around 1/4 throttle. I believe it's around 1/4 throttle I need to concentrate on though I may mark the throttle and check exactly where I want to target.

I will definitely try to get hold of a CCK and try that set-up I have the 7 slide from the previous set-up. Is the CCK a standard Kehlin needle or some-one else's OEM needle? It would be nice to be able to easily find info in the diameters/tapers etc and be able to move up or down a needle size in necessary.

Thanks for the replies so far!

The CCK is a Keihin standard needle with a single taper angle.

The N1EF is a special triple taper needle developed by the mfr. It is primarily designed for racing applications. It is richer in the 1/8 to 1/4 throttle range. As such it does not work real well for sustained low throttle trial riding. In the 1/4 to 3/4 throttle range the taper angle is very similar. In the 3/4+ throttle range the triple taper needles are a bit richer than a comparable straight taper needle. This can be mostly compensated by main jet sizing for trail riding applications.

For standard Kehin needle specs see... http://www.carbparts.com/keihin/need..._34_39_jn.html