2014 Gas Gas 300 - Jetting
- Thread starter n_green
- Start date
Currently 40pilot, NEDJ#2, 168
Main. Air screw is 1.3 turns out.
That's on a 300 which has had the head modified (squish band adjusted to 1.3mm, angle corrected to match piston dome, chamber adjusted to leave comp ratio at approx 13:1.
Riding in Australia, temps between 10-20 deg, 60-75% humidity, 350m altitude.
The 250 wouldn't have as strong a signal so would need richer settings everywhere. I'd try something along the lines of 42 pilot, NECW#3, 175main and see how it goes.
Jake should chime in soon, he is the guru and owns 250's and will be prepping a 2015 250 soon. So stay tuned.
Main. Air screw is 1.3 turns out.
That's on a 300 which has had the head modified (squish band adjusted to 1.3mm, angle corrected to match piston dome, chamber adjusted to leave comp ratio at approx 13:1.
Riding in Australia, temps between 10-20 deg, 60-75% humidity, 350m altitude.
The 250 wouldn't have as strong a signal so would need richer settings everywhere. I'd try something along the lines of 42 pilot, NECW#3, 175main and see how it goes.
Jake should chime in soon, he is the guru and owns 250's and will be prepping a 2015 250 soon. So stay tuned.
Rode yesterday, 20deg C, 55% humidity, 300m asl.
40p, NEDJ#2, AS 1.3, 168m.
Ride consisted of 70kms, 60kms of which was tight techy single, mostly second gear with occasional first gear techy climbs.
The bike is still very rich just off idle. Burbles as usual (though no spooge which is interesting - Castrol TTS @50:1)
There is a massive flat spot in the power before it comes onto the pipe, a lot more noticeable today probably due to the warmer weather.
Clears up and comes onto the pipe quite well though still feels a bit flat. I'm confident it's a rich condition, to clarify I swapped bikes with a mate for a while and asked him for his thoughts. He agrees here is a huge area where the jetting is too rich and it is choking the power of the bike.
Fuel use was 7l for 68k of riding.
I'm waiting on a #8 slide to try, if this doesn't arrive soon I may go for a ride armed with NEDW#2 and NEDK#2 and swap needles leaving jets alone. Should confirm for me at least that it is a rich condition. Who knows the K diameter may fix it haha.
40p, NEDJ#2, AS 1.3, 168m.
Ride consisted of 70kms, 60kms of which was tight techy single, mostly second gear with occasional first gear techy climbs.
The bike is still very rich just off idle. Burbles as usual (though no spooge which is interesting - Castrol TTS @50:1)
There is a massive flat spot in the power before it comes onto the pipe, a lot more noticeable today probably due to the warmer weather.
Clears up and comes onto the pipe quite well though still feels a bit flat. I'm confident it's a rich condition, to clarify I swapped bikes with a mate for a while and asked him for his thoughts. He agrees here is a huge area where the jetting is too rich and it is choking the power of the bike.
Fuel use was 7l for 68k of riding.
I'm waiting on a #8 slide to try, if this doesn't arrive soon I may go for a ride armed with NEDW#2 and NEDK#2 and swap needles leaving jets alone. Should confirm for me at least that it is a rich condition. Who knows the K diameter may fix it haha.
One thing I didn't mention in the previous post is that the ride the other day was a 2 part ride, 70 k's described above to lunch stop and then 60k's on the way home, which due to running out of sunlight consisted of 90% firetrail/faster 3rd/4th gear twin trail with only the occasional bit of single or snotty hill.
Obviously this part of the ride was spent majority of time well and truly on the taper, although on the firetrails we were just cruising at 60-70ks.
Out of curiosity today I measured how much fuel I used on the way home, surprised to find I only used 4.3l which is economy of 7.3l per 100ks.
This is a good sign, if I can just get the bottom end cleaned up I may just get 100+ k's out of a tank.
Obviously this part of the ride was spent majority of time well and truly on the taper, although on the firetrails we were just cruising at 60-70ks.
Out of curiosity today I measured how much fuel I used on the way home, surprised to find I only used 4.3l which is economy of 7.3l per 100ks.
This is a good sign, if I can just get the bottom end cleaned up I may just get 100+ k's out of a tank.
Jakobi
Super Moderator
I'm going to try an NEDJ#2 in my 250 to see what effect it has on my bottom end. I have a light, but noticable burble at part throttle. Quite noticable if someone else rides my bike. Seems these days I've got the throttle open enough that I don't really notice it unless looking for it.
Threw in NECK#3 today, only rode it around the house (I live in suburban sydney so can really only test idle and just off idle) seems to idle well and have good response (on the stand) with the AS at 3/4 out and riding it round the back yard at walking pace in second (with clutch) seems ok. Seems a bit cleaner off the bottom. Just need to get it out on the dirt now to test it out
Obviously I didn't get to test the NECK#3 needle, as on the ride where I was supposed to be testing it 7k's into the ride I went over the bars at 75kph which resulted in a pretty bent bike and badly bruised and battered me :roll eyes:
Bike and body are all better now, and whilst I was injured the #8 slide that I've been waiting for arrived (borrowed from a friend). I need to test it and give it back, so in it went along with a NEDJ#2, 40p and 168m. Started it up and warmed it up, refused to idle, even with the AS at 3.5 turns out. Super rich.
Swapped the 40p for a 38p, and with the AS at roughly 1.75 turns out it has a decent idle and good response to being revved on the stand. Seems to be a very fine line between lean hesitation off idle and dying when coming back down to idle. Rode it round the back yard in first and second at walking pace and it seems ok, maybe rich but I need a decent ride to confirm.
I'm not convinced the leaner slide has done that much to be honest, but a decent dirt test should confirm it.
Bike and body are all better now, and whilst I was injured the #8 slide that I've been waiting for arrived (borrowed from a friend). I need to test it and give it back, so in it went along with a NEDJ#2, 40p and 168m. Started it up and warmed it up, refused to idle, even with the AS at 3.5 turns out. Super rich.
Swapped the 40p for a 38p, and with the AS at roughly 1.75 turns out it has a decent idle and good response to being revved on the stand. Seems to be a very fine line between lean hesitation off idle and dying when coming back down to idle. Rode it round the back yard in first and second at walking pace and it seems ok, maybe rich but I need a decent ride to confirm.
I'm not convinced the leaner slide has done that much to be honest, but a decent dirt test should confirm it.
Two stage trip today - Leg 1 consisted of 42k's, mostly tight techy 2nd gear single with some snotty techy hills thrown in for good measure. The bike went upside down once or twice (re-tweaking my subframe and smashing the brand new overpriced POS gas gas light switch! 
)
Riding there and the bike is filthy rich off the bottom, it was almost the same as riding a cold engine it was that blubbery
Refused to idle at all, then the battery died so no e-start all day :roll eyes:
When it eventually cleared up, and it took a long long time to do so, it was ok, though pretty underpowered up top, bit lean on the main.
Filled up at lunch stop - 5.8l used for 42k's!
At lunch out came the NEDJ and in went the NECK#3. Also upped the main to a 170. Started riding back home, lasted about 5 k's and out came the #8 slide. Still super blubbery off the bottom, even using an NECK needle with a 38p.
Now using 38p, NECK#3 AS 0.75 out, 170m, rode the rest of the way home. Still slightly blubbery off the bottom at very small throttle openings, but starts clearing up very quickly and by the time it's at 1/4 throttle its pretty nice.
The top end is back, nice and strong, pulls hard and will bring the front up in 3rd and 4th rolling on the power.
Still a bit fat off the bottom, the rich to lean hesitation is back, though not as bad as what it was with the J needle. I may drop the needle to clip 2, that should just about sort it.
Fuel use was 3.8l for 34k's. The first 5k's was using the #8 slide, but shouldn't skew results that much.
Still not great, dropping the needle a clip better improve fuel use a hell of a lot.
Was riding at sea level, 28 deg C day, 40% humidity.
)Riding there and the bike is filthy rich off the bottom, it was almost the same as riding a cold engine it was that blubbery
Refused to idle at all, then the battery died so no e-start all day :roll eyes:When it eventually cleared up, and it took a long long time to do so, it was ok, though pretty underpowered up top, bit lean on the main.
Filled up at lunch stop - 5.8l used for 42k's!
At lunch out came the NEDJ and in went the NECK#3. Also upped the main to a 170. Started riding back home, lasted about 5 k's and out came the #8 slide. Still super blubbery off the bottom, even using an NECK needle with a 38p.
Now using 38p, NECK#3 AS 0.75 out, 170m, rode the rest of the way home. Still slightly blubbery off the bottom at very small throttle openings, but starts clearing up very quickly and by the time it's at 1/4 throttle its pretty nice.
The top end is back, nice and strong, pulls hard and will bring the front up in 3rd and 4th rolling on the power.
Still a bit fat off the bottom, the rich to lean hesitation is back, though not as bad as what it was with the J needle. I may drop the needle to clip 2, that should just about sort it.
Fuel use was 3.8l for 34k's. The first 5k's was using the #8 slide, but shouldn't skew results that much.
Still not great, dropping the needle a clip better improve fuel use a hell of a lot.
Was riding at sea level, 28 deg C day, 40% humidity.
Jakobi
Super Moderator
I find even a half clip position change is pretty big, and noticably effects both how the engine runs and how much juice it chews.
I'm interested to see how mine feels as lean as 40 NECW#2 175. I've also noticed sensitivity in the AS, where 2 turns out gives a really nice idle and some slight hesitation whacking the throttle open (but not a lean stall). 1.5 turns is noticably blubbery, and the ideal balance somewhere in between depending on the day.
I'm interested to see how mine feels as lean as 40 NECW#2 175. I've also noticed sensitivity in the AS, where 2 turns out gives a really nice idle and some slight hesitation whacking the throttle open (but not a lean stall). 1.5 turns is noticably blubbery, and the ideal balance somewhere in between depending on the day.
96ks yesterday. <500m asl, approx 25-30deg C, 40-50% humidity.
40p, AS 0.8 turns out, NEDK#2, 170m.
70k's was majority tight mid 2nd/low 3rd gear single with some nice and some not so nice hills thrown in. Nothing to techy but some of the hills were steep, slippery and covered in ruts and roots.
Rolling on the power felt ok. Blubber is still present just off idle through to 1/8 throttle when not under load. It's there when under load but not as perceptible.
Clears out and come onto the pipe better but still some hesitation and the overrev isn't very impressive either.
I think I'm a tad lean on the taper now and also main. When accelerating up a hill pulling the choke on actually makes it rev harder/faster so it needs a bit of extra fuel in there somewhere.
Transition through the rev ranges is smooth and predictable. Small hit of power coming onto the pipe but not too bad.
It lacked power off the bottom all day, I had to abuse the clutch a lot on steep rutted out uphills and the bike was boiling quicker then the KTMs present. Others commented that it sounded like it had no power off the bottom. The small pilot is probably to blame, should have gone to a 42 and wound the as out a bit more.
Dunno where to go from here, up the pilot and main by 1 size and see what happens or step the diameter down to a J, same clip position and up the main at the same time?
Buy a lectron or smart carb and hope the hype is finally true?
40p, AS 0.8 turns out, NEDK#2, 170m.
70k's was majority tight mid 2nd/low 3rd gear single with some nice and some not so nice hills thrown in. Nothing to techy but some of the hills were steep, slippery and covered in ruts and roots.
Rolling on the power felt ok. Blubber is still present just off idle through to 1/8 throttle when not under load. It's there when under load but not as perceptible.
Clears out and come onto the pipe better but still some hesitation and the overrev isn't very impressive either.
I think I'm a tad lean on the taper now and also main. When accelerating up a hill pulling the choke on actually makes it rev harder/faster so it needs a bit of extra fuel in there somewhere.
Transition through the rev ranges is smooth and predictable. Small hit of power coming onto the pipe but not too bad.
It lacked power off the bottom all day, I had to abuse the clutch a lot on steep rutted out uphills and the bike was boiling quicker then the KTMs present. Others commented that it sounded like it had no power off the bottom. The small pilot is probably to blame, should have gone to a 42 and wound the as out a bit more.
Dunno where to go from here, up the pilot and main by 1 size and see what happens or step the diameter down to a J, same clip position and up the main at the same time?
Buy a lectron or smart carb and hope the hype is finally true?
In my humble opinion you are using a very lean needle. His GasGas AS2 uses a 38mm carb, right?
I've fought a lot with the GasGas carburetion, and in my testing I found that a richer needle associated with a smaller pilot jet brings better results. You have to test a NECW needle?
Another detail, a motorcycle 2T always need a small excess to 1/8, if it is too smooth / clean on this track without charge, will inevitably lose torque / heat easily under stress.
You commented that you need to abuse the clutch, this is a classic symptom that your bike this very poor.
I've tested a Lectron 38m and honestly did not realize advantages over well-adjusted Kehin.
I've fought a lot with the GasGas carburetion, and in my testing I found that a richer needle associated with a smaller pilot jet brings better results. You have to test a NECW needle?
Another detail, a motorcycle 2T always need a small excess to 1/8, if it is too smooth / clean on this track without charge, will inevitably lose torque / heat easily under stress.
You commented that you need to abuse the clutch, this is a classic symptom that your bike this very poor.
I've tested a Lectron 38m and honestly did not realize advantages over well-adjusted Kehin.
I agree with you, I don't like the idea of a K diameter being in there, however it has cleaned up the bottom end somewhat, although it has caused a massive loss in power. Overheating and lacking torque its obvious the needle is too lean. Funny though even after abusing the hell out of it up hills and getting it bloody hot it never idled up or run on, and certainly never pinged.
I've tested a 'W' diameter in the past, pre head mod I was having great results with the 'W' diameter.
Plan from here is to up the pilot to a 42 and main to a 172 and leave the needle for now, test it again and see what happens. Good times
gg3
Silver Level Site Supporter
Been following the thread so don't give up yet!
I have got to a main 175,JD Blue #3,40 pilot,AS2.5(had the JD kit from previous bike) .
2014 300 replica,sea level to 500m,20-27 Celsius.
To be honest I didn't think stock jetting was that bad just a little lean.
Didn't run well on the JD Red but the blue fattened it all up. A little rich off the bottom but pulls hard & clean mid to top. I have had only one real test ride that was so wet & slippery it was hard to get a lot of feed back. But a lot of hard revving stuck on hills with bike queues, clutch abuse & covered in thick mud. Never got hot & would chug down low. Feel pretty close to how I want it ,not right or wrong but how I like it. Last gasser had an NEDJ needle, fantastic! Sold it with the bike though.I read you didn't like it in this bike but I think I am going to get another & try. No head mods on mine which would make comparative jetting specs to yours difficult I guess?
I have got to a main 175,JD Blue #3,40 pilot,AS2.5(had the JD kit from previous bike) .
2014 300 replica,sea level to 500m,20-27 Celsius.
To be honest I didn't think stock jetting was that bad just a little lean.
Didn't run well on the JD Red but the blue fattened it all up. A little rich off the bottom but pulls hard & clean mid to top. I have had only one real test ride that was so wet & slippery it was hard to get a lot of feed back. But a lot of hard revving stuck on hills with bike queues, clutch abuse & covered in thick mud. Never got hot & would chug down low. Feel pretty close to how I want it ,not right or wrong but how I like it. Last gasser had an NEDJ needle, fantastic! Sold it with the bike though.I read you didn't like it in this bike but I think I am going to get another & try. No head mods on mine which would make comparative jetting specs to yours difficult I guess?
Rode yesterday - 300m asl, 25-30 deg C, 50% humidity.
...
The ride consisted of two stages, first stage covered 67k's, covered approx 40k's was flowing 2nd/3rd gear single remaining 30k's was transport firetrail.
First stage I used:
40p, AS1.4, NEDJ#2, 172m.
This jetting was pretty good, it had a decent idle and off idle response. Pretty good torque, although I did find it a tad lacking at times on steep snotty hills where slipping the clutch in second didn't cut it and required a down-shift to first. It wasn't lean at all, still had a slight blubber present even under load, but it didn't build up and require cleaning out.
The top end was quite good, it wasn't mind blowing but definitely had a lot more power then when I was using a 168 main, so obviously the hesitation in the transition I was feeling previously was just a slightly lean symptom.
Fuel use was 6.3l for 67k's = 10.6k's per Litre.
Of interest there were two other Gassers along for the ride, a 2010 running 42p, N3CJ#3, 178m - used 5.5l and a 2012 running 42p, NECJ#3, 175m - used 5.8l.
At lunch I swapped jetting to N3CJ#3, 178m (who doesn't carry spare needles and jets in their bumbag haha) retained the 40p with the AS 1.4.
Return leg was 58k's, again 20-25k's of this was transport firetrail, the remaining 35k's was flowing 3rd gear single.
This jetting is SO much better then the NE needle. Immediately I noticed the idle was a bit higher using this needle, wicking the throttle response was just as good if not better. There is so much more torque with this jetting, I was lugging it up hills in second that the NE needle would have required first gear for. Whilst there is a slight blubber under load its not too bad and doesn't load up too much. The top end is so much better using the N3 needle, from low revs in 4th gear it rolls on smooth and predictable before exploding into an awesome top end. There is a bit of a lull before it comes onto the pipe, I have a feeling half a clip leaner would do the trick, will experiment another time.
Fuel use was 4.5l for 58k's = 12.8k's per Litre.
The 2010 used 4.1l and the 2012 had a quick look at his tank and has used between 4 - 4.5l so we used similar fuel for the same k's which is a good sign.
Admittedly both of these results are highly likely to be skewed based on the amount of firetrail covered, I generally try and avoid firetrail at all costs so the next decent ride covering all single trail will reveal this jettings real economy.
Having said that, for now I'm happy with this jetting, pretty clean, great predictable power, potentially good economy, may play with half clip options for giggles but for now this is a winner.
...
The ride consisted of two stages, first stage covered 67k's, covered approx 40k's was flowing 2nd/3rd gear single remaining 30k's was transport firetrail.
First stage I used:
40p, AS1.4, NEDJ#2, 172m.
This jetting was pretty good, it had a decent idle and off idle response. Pretty good torque, although I did find it a tad lacking at times on steep snotty hills where slipping the clutch in second didn't cut it and required a down-shift to first. It wasn't lean at all, still had a slight blubber present even under load, but it didn't build up and require cleaning out.
The top end was quite good, it wasn't mind blowing but definitely had a lot more power then when I was using a 168 main, so obviously the hesitation in the transition I was feeling previously was just a slightly lean symptom.
Fuel use was 6.3l for 67k's = 10.6k's per Litre.
Of interest there were two other Gassers along for the ride, a 2010 running 42p, N3CJ#3, 178m - used 5.5l and a 2012 running 42p, NECJ#3, 175m - used 5.8l.
At lunch I swapped jetting to N3CJ#3, 178m (who doesn't carry spare needles and jets in their bumbag haha) retained the 40p with the AS 1.4.
Return leg was 58k's, again 20-25k's of this was transport firetrail, the remaining 35k's was flowing 3rd gear single.
This jetting is SO much better then the NE needle. Immediately I noticed the idle was a bit higher using this needle, wicking the throttle response was just as good if not better. There is so much more torque with this jetting, I was lugging it up hills in second that the NE needle would have required first gear for. Whilst there is a slight blubber under load its not too bad and doesn't load up too much. The top end is so much better using the N3 needle, from low revs in 4th gear it rolls on smooth and predictable before exploding into an awesome top end. There is a bit of a lull before it comes onto the pipe, I have a feeling half a clip leaner would do the trick, will experiment another time.
Fuel use was 4.5l for 58k's = 12.8k's per Litre.
The 2010 used 4.1l and the 2012 had a quick look at his tank and has used between 4 - 4.5l so we used similar fuel for the same k's which is a good sign.
Admittedly both of these results are highly likely to be skewed based on the amount of firetrail covered, I generally try and avoid firetrail at all costs so the next decent ride covering all single trail will reveal this jettings real economy.
Having said that, for now I'm happy with this jetting, pretty clean, great predictable power, potentially good economy, may play with half clip options for giggles but for now this is a winner.
Last edited:
jpgibson
Bronze Level Site Supporter
Lucky I'm reading this at work!
My 2010 had the head cut and jetting was perfect.After reading all of this, it seems with the newer bikes, it just adds headaches!
My 2013R ( AS1.75-2, 42PJ,N3CJ #3,175) has a bit of burble just off idle and stalls easier than my 2010 but I wonder if that's the way it has to be. I have cut the Q Stealth down, have no spooge and a tan plug.Starts easily and idles.
I dont know if I'd have the patience of you guys to chase the ( somewhat annoying) burble.
Maybe try a 40 PJ? Or just go to clip position#2
My 2010 had the head cut and jetting was perfect.After reading all of this, it seems with the newer bikes, it just adds headaches!
My 2013R ( AS1.75-2, 42PJ,N3CJ #3,175) has a bit of burble just off idle and stalls easier than my 2010 but I wonder if that's the way it has to be. I have cut the Q Stealth down, have no spooge and a tan plug.Starts easily and idles.
I dont know if I'd have the patience of you guys to chase the ( somewhat annoying) burble.
Maybe try a 40 PJ? Or just go to clip position#2
While the burble can be annoying I can put up with it. What I couldn't put up with was only getting 65-75ks from a tank including reserve!
Hence my search for jetting nirvana. Almost there I think.
Btw N3CJ needle in clip #2 is rocketship territory. Very snappy.
Sent from my iPhone using Tapatalk
Hence my search for jetting nirvana. Almost there I think.
Btw N3CJ needle in clip #2 is rocketship territory. Very snappy.
Sent from my iPhone using Tapatalk
Jakobi
Super Moderator
You may find going the half clip leaner on the N3xx will increase the lull as it comes onto the pipe, and make it pull even harder in the transition. Thats what I have found.
I've been running 40 NEDW#2 175 in my 2013 250 with modded head and the bike starts and runs well. Its got some fluff off the bottom as noted, and is very sensitive to AS adjustments. An eighth of a turn can make it go from punchy and responsive to lacking nuts (most noticable in the upper gears). Fuel economy is spot on for me.
I love the N3xx on the old engine, but didn't work so well on the new one.
I've been running 40 NEDW#2 175 in my 2013 250 with modded head and the bike starts and runs well. Its got some fluff off the bottom as noted, and is very sensitive to AS adjustments. An eighth of a turn can make it go from punchy and responsive to lacking nuts (most noticable in the upper gears). Fuel economy is spot on for me.
I love the N3xx on the old engine, but didn't work so well on the new one.
