2011 ASII 36 Jetting - what were they thinking?

[Neil E.]

The monsoon season is over here. I got out for a first ride with some buddies. The jetting is so rich, it runs like the air filter is totally plugged. They must have intended the jetting to be used at 20*F at sea level.

The stock settings: 6.5 slide, 42pilot, 175main, N1EF, 1T air screw. The bike idles (sort of) and the air screw has little effect. There is no "get up and go". I'm using Ipone Samurai at 50:1 and the riding is mostly singletrack. Elevation 1000 - 1200', temperatures 60-80*F.

The exhaust sound is dull on accel or decel. After about an hour of riding I notice a distinct knock from the engine on decel. Soon I get this knock on every gear change (when I close the throttle to shift). Time to head back to the parking lot. Keeping the throttle steady helps.

Burhan (EC300) tells me that the manual recommends changing the plug after the first hour of operation. I put in a new NGK (the plug in the bike is a Nippon Denso).

Head back out and everything is OK again. The engine runs marginally crisper (still a long way from crisp). After an hour, the knock is back. Soon it's getting dark and time to end the ride.

The next day I pull the NGK (left) to compare it to the Denso (right).

My exhaust tip is messy and the inside is very oily. I'm not worried about spooge, the angled outlet does a great job of keeping the rest of the bike clean.

Having a stock needle that is crazy rich with the clip already in the top groove is nuts. Not even one groove of adjustment is possible. Have any of you 2011 owners found a needle that runs well with the clip in the center groove?

I'd like to know what the cause of the "knock" is. It's just like a single "pre-ignition" detonation. I can only guess that fuel mixture builds up in the pipe and ignites.

 

[Bailey28]

The knock, or "kack" as I call it is the exhaust loading up with unburnt fuel. It will happen if you don't "clean it out" after warming the bike up after you first start it too. (Get the bike on the pipe for a few gears)

I had to go a little leaner on my jetting on my 300 to get that to stop. I also noticed that if I am in the woods all day, I could use leaner overall jetting vs. riding a motocross track as I also do on my 300.

Unfortunately I cannot suggest jetting changes for your 250 specifically, but I can say that you may want to go leaner.

 

[mrkartoom]

I agree I'd go down pilot size a step at a time to see if that improves it. 42 seems kinda fat to me, but can't say for sure. GMP has a lot of experience with 250's I think, he may know what that needle and slide will run with in that carb. He may chime in. I've got a good setting for a 250, but different carb and slide so it's no good to you.

What is that snorkel?

 

[Neil E.]

That is a piece of 316 stainless steel dairy tubing, specifically a 1" x 45* long tangent elbow for TIG welding. I machined up an adapter to fit the muffler end cap and silver soldered the tube in. The adapter has a tapered bore and is a snug fit into the muffler. A bead of medium temperature silicone holds it firmly in place.

On my first parking lot ride, my jacket stunk of 2T oil. The Krizman "bullet" is very near the rear of the muffler and makes the exhaust swirl enough to deposit oil mist on the fender. Some oil mist also gets drawn into the still air pocket behind the rider. An angled tip was an easy way to stop this. A side benefit is the exhaust is directed away from a following rider when on the trail.

I like that the angled outlet creates a "drip point" for spooge; that way it can't run back down the muffler.

 

[mrkartoom]

Good job. Has that factory look.

 

[Jakobi]

The sound.. Would describe it as a "GUNG!!" only ever one. As mentioned its the exhaust loading up with unfburnt. Usually a sign of a rich pilot and happens on decel.

Same settings my 2010 300 came with on a 300 with 38 mm pwk asII.. My plug was the same.. Still chasing the answer somewhat..

 

[biggstr6]

my 2011 EC300 sixdays has the 36mm ASII 6.5 slide and was crazy rich as well.

I got the YZ needle N3eJ , went to a 40 pilot & 180 Main and it made a world of difference . Sea level - 2000 ft ,80 degree temps.

Havent had a chance to check the top end WOT yet ,but 1 & 2 and right off idle are much better.

I copied the settings from Reverup.

 

[Bikerdad450F]

2009 EC300, also chasing jetting

Brand new bike, came with N1EF needle also clip in top grrove, not happy about that, yes it seemed to run best that way but not good enough, I've spent lots of time richening and leaning both pilot and main jet, to no avail, and I have a JD kit on order, I see the jetting database is fairly stagnant for newer models, but there are tonnes of helpful posts here to watch and learn from. I'll post back here If the JD kit helps, I will likely not stop there though, I will order in some of the various Keihin needles and experiment.
My bike has mediocre power down low (good enough but not crisp) a very crisp mid range, snappy even. but if I turn the throttle past 3/4 it falls flat, to recover you must roll back to 3/4 and upshift (if you still want to go faster).
this is more than enough power for trail riding because I'm never revving it in the bush/ trees, but when you get out in the open for a minute it sucks.

 

[Bikerdad450F]

Brand new bike, came with N1EF needle also clip in top grrove, not happy about that, yes it seemed to run best that way but not good enough, I've spent lots of time richening and leaning both pilot and main jet, to no avail, and I have a JD kit on order, I see the jetting database is fairly stagnant for newer models, but there are tonnes of helpful posts here to watch and learn from. I'll post back here If the JD kit helps, I will likely not stop there though, I will order in some of the various Keihin needles and experiment.
My bike has mediocre power down low (good enough but not crisp) a very crisp mid range, snappy even. but if I turn the throttle past 3/4 it falls flat, to recover you must roll back to 3/4 and upshift (if you still want to go faster).
this is more than enough power for trail riding because I'm never revving it in the bush/ trees, but when you get out in the open for a minute it sucks.

I should add: # 7 slide, 38 mm carb, 40 to 42 pilot, 178 to 180 MJ, (still) top clip groove N1EF needle, clean air filter.
I'm also looking to get a #8 slide to try. (leaner)

 

[Tlineman]

Not sure on the 36mm, maybe leaner settings yet than the 38mm. I run a CCK needle with a 38PJ and a 175 main, A/S 1 1/2 turns out in a 38mm carb. I ride typically from 2500 to 4500 feet and lately around 60 - 80 deg. My bike runs crisp. Slight gurgle at WOT in rain mode, crisp in sunshine. Absolutely no spooge whatsoever.

My buddies identical bike, same year, carb, cc runs like crap with my jetting. We're jet to divulge into why this is, but my suspicion is it has to do with the PV settings or adjustment.

I'd keep the CCK needle a try, they're cheap, order from Sudco. You may not like it though as it turns the bike into a fire breathing tire shredder

 

[Tlineman]

should probably mention that I lowered the float slightly as it was dribbling gas, even on the kickstand. This may have helped the jetting.

 

[Sixdays]

I just bought a new 2011 300 SD.

Mine has the old style 38. The only jetting mod mine needed was to drop the stock main down from a 175 to a 165. Needle stock and pilot stock (didnt even look at what they were)

The bike runs perfect at at 4500 ft up to 7000 ft. It will idle all day long and never loads up or spooge on the muffler.

I did do a compression test today and it was 170 dead cold and dry. I will do a squish test in the morning and report back.

I rode the GG back to back with a 09 ktm 250 with a new 300 sx kit 2 weeks ago. The GG had more low end than the ktm and slightly less top. From what I have read it should be the other way. This GG really impressed all of the guys we rode with.

 

[Jakobi]

I personally think most of these issues will end up being related to the squish band. Some come closer to where they should be and as such run as expected. Others well out that make jetting changes inconsistant.

The other factor is how many of these bikes are actually jetted correctly as in you can move your clip position without the idle circuit being affected. I have a suspicion that alot of the bikes have been jetted to work but aren't really jetted as well as they could be.

I'm yet to find a needle diameter that will idle on its own with a 38 pilot and the slide just lifted. I have tried everything from F G H J. I know of one other running a 38mm carb with a 35 pilot AS 3 turns out with a G diameter needle.

Some will say that a leaner slide is required. I personally feel the squish band is probably closer to 3mm than 1.25mm. I'll check when its time for a top end (soon). And may replace with an S3 head for some added compression and bling.

 

[Neil E.]

I'm just a casual trail rider, so power is not important to me. Clean running at low speeds is critical. My bike has to be tilited a long way over before it loses fuel out the overflow, so I believe the float height is adequate. There is no rattle from the power valve, so it is probably preloaded OK. I'll bet the squish is poor based on how much variation there is between bikes.

It looks like the first test should be the N3EJ needle and a leaner slide. Does anyone have information on the slide cutout dimensions?

 

[thumperrider1]

I run a JD jet kit from a Yamaha YZ250 using the recommended settings. Works great. I have the 38mm carb, but I'm sure it will work well on the 36 with a little tweak of the clip position and AS setting.

 

[Neil E.]

I wouldn't run out and buy a JD kit for a "problem" engine. Poor squish would require more tweaking than what a standard kit could accomplish.

Aside from correcting the squish, the best solution is likely a leaner slide. The cost of a slide is so high that I'd mess with needles first. A triple taper needle with a large diameter and shallow first taper would lean things out.

Some folks get bent out of shape over pilot sizes, but very large (or small) pilot jets are just matching up for the needle shank diameter.

I'm having trouble finding a decent needle chart. There are ones available for the three digit code option needles like CCK. What chart do you guys use for needles like N3EJ?

 

[tanderson91]

well i have a 2011 3oo. i run nozh needle in third setting 38 pilot 168 main air screw out 1.5- 2, bike is very crisp that needle is a ktm series needle sea level 1000 feet

 

[Neil E.]

I emailed back and forth with James Dean. He is in the process of making a kit for the newer GasGas bikes. It will have number JDG002. He says there will be no need for anything other than his needle kit. His slide price is good, so it will be cost effective to make additional changes. I think more than just the kit will be required when it comes to a problem bike like mine.

I will check my compression pressure, squish clearance and power valve play. There may be some clues to be had there.

 

[cdn280]

Neil, I run a #7 slide in mine if you want the dimensions. I also use a LTR needle which transformed the engine. Its a very shallow taper compared to the stock N1 needles so if the KTM N3 is like that try one. Don't know if LTR still has them, and don't think I had it in when you rode it. It gave it a steady idle speed (not drop to putt putt blubber like stock) and is willing to idle all day without loading up, more responsive to AS adjustment, and smoother roll on power.
I also found that with the stock float height it would pee gas out as a minimal lean angle. Reducing it by .5-1mm fixed that.

 

[Neil E.]

Mike,
The problem right now is that suppliers in Canada stock bugger all, so it's hard to get any carb parts. I'll check the mechanicals soon. The bike is basically unrideable with the stock jetting.
Neil