Needle suggestion for '01 300

[TheLetterJ]

I have a 2001 EC300 with 38mm AS1 currently jetted 42p, 172m, needle (unmarked) on 2nd clip, a.s. 2 3/4 turns out, #7 slide. Riding mostly between 2500'-5000' temp 70*-80*F humidity typically around 50%. 40:1 premix.

It runs pretty good and does not load up excessively or spooge out the silencer... until this past Saturday. I was riding a "trail" that had me in first gear the entire time with very low throttle openings under pretty heavy loads (except when I had to whack the throttle open and drop the clutch to get up rock faces/ dry waterfalls) and I noticed that after a while in these conditions I could smell the exhaust much more than usual and I eventually had some spooge at the end of the silencer. Idle-1/4 throttle is my primary focus, but if I can get a bit more "snap" everywhere else that would be a bonus.

I have spent the last 2 days reading everything that I can on the matter and it is still as clear as mud to me. I like what I have been reading about the NEDJ, but after reading several hundred posts on the matter I have seen many people mention that the NEDJ is too lean of a needle for the AS1. What needle would work in my AS1 to clean up the bottom end and possibly get a little more response across the board?

 

[webmaster]

The unmarked needle is probably from an LTR jetting kit - which is no longer marketed. But worked well in my old '01 - actually my bike was used to create it... The numbers were machined off so that it wouldn't be copied immediately...

What you describe to me sounds perfectly normal - a 2 stroke will "load up" if lugged around too much. The next time you are in this situation - pull in the clutch every once in a while and blip the throttle 2-3 times to "clear it out".

If you step up and have Ron @ RB-Designs mod your carb. It will run a bit cleaner and have finer adjustability on the air screw. If you want to stick with what you have - and focus on low end chug - you might want to try 6 or 6.5 slide.

For cleaner running - It will also help to have your head squish done by Ron - if it hasn't been done already, I would budget for this first. biggest bang for the buck. $75.00. He will dial the compression in for the range of elevations you ride.

If you do have your carb done by Ron - and it has alot of time on it - ask Ron if he can replace the nozzle jet in the carb for you. He used to do offer this - but I don't see it on his website... On the bikes with Boyeson Rad Valves this was more of an issue (? maybe?) - one theory is the setup transferred greater vibration to the carb and wore the nozzle into an oval over time - making for very difficult jetting.

jeff

 

[TheLetterJ]

I am 99% certain that the needle is not from LTR just based on the fact that when I bought the bike a little over 2 years ago it looked like it had just come out of the crate... nubs on original tires and all. It had less than 10hrs total on it then and the previous owner told me that all he did was add the skidplate/ radiator braces, and fastway pegs.

I've put roughly 100hrs on it since and my above jetting was as close as I could get with my otherwise stock engine and what I assume to be the OEM needle. I still think the needle is just a tad too rich at the idle-1/4 throttle range.

The head mod is on the list but it will have to wait until after October as we have a few major rides planned and I can't afford the downtime (minimal as it may be)

This is some of the typical terrain I ride my Gasser in, you can see how immediate bottom end response would be very useful!



There is no slop in the powervalve either and I plan to lower the cylinder before sending the head off, I'm just looking for a less invasive way to clean up the bottom end for now and a leaner needle seams like it would be the ticket.

 

[webmaster]

Nice Pic.

Do you have a G2 throttle? I ran a honda tlr200 trials throttle on my '01 for a while - made it alot easier for me to control in the tight stuff. Kinda of a long throttle pull though. The G2 cam with the greatest ramp is a good compromise - the 400 cam. More control at bottom then ramps to give close to normal throttle pull.

Is your idle screw all the way in to being near coil bound? Does it not idle well? Does your air screw have little effect (seems insensitive to changes)? If yes to all of the above, that that would indicate stock jetting - which in that year would mean a very "non-optimal" n1ef needle.

It still sounds like it was jetted w/ LTR kit. - I just talked to Les @ LTR on the phone - he is my best friend from childhood. He told me he would recommend 42-45 pilot and 172-175 main in later years. his needle in #2 position. Which is right where you are at.

jeff

 

[webmaster]

Just checked around and Roscoe was running an oem yamaha needle on his newer gasgas with good success.

36mm Air striker 2 carb Slide #6.5 with notch.
Yamaha YZ 250 2 stroke factory carb needle N3EJ clip in center position #3
Pilot jet #40
Main #180
1 turn out on air screw

If it were me and I still had my '01 in your situation - I would start with this. I think the 6.5 slide would be optimal - but 7 would be okay to start.

Jakobi is the jetting expert in these parts and he might chime in with his thoughts when he wakes up (australian...)

jeff

 

[jhendr3702]

i would agree with Jeff... when i picked up my 01 is was like yours.. nubbs still on the tires and almost 8 years old..
it had a n1ee 35 pilot and i dont remember on the main.. i talked to les also he told me that was oe jetted for that year..

is the needle in yours brass colored or silverish ? i ordered one of his jet kits and am pretty sure the needle was brass... the n1ee was silver

funny thing is mine ran ok for almost a year with that setup.. we are about the same altitude.. we had a pretty big temp/humidity change one year and it would barely run..

my 01 did not really like the nedX needles... iirc, a cek was what ran best in it... but i am learning there are no 2 exactly the same bikes...

 

[TheLetterJ]

Nice Pic.

Is your idle screw all the way in to being near coil bound? Does it not idle well? Does your air screw have little effect (seems insensitive to changes)? If yes to all of the above, that that would indicate stock jetting - which in that year would mean a very "non-optimal" n1ef needle.

It still sounds like it was jetted w/ LTR kit. - I just talked to Les @ LTR on the phone - he is my best friend from childhood. He told me he would recommend 42-45 pilot and 172-175 main in later years. his needle in #2 position. Which is right where you are at.

jeff

My idle screw is nearly buried and the air screw does have little effect. I swapped in the 42/172 and put the needle in the second clip position myself after much experimentation, it was previously 48/175 3rd clip. It would idle until the tank ran dry with the original jetting, but would burble like crazy at almost every throttle opening. Like jhendr3702 pointed out, my needle is silver in color as opposed to brass, so I fully believe it to be original to my bike.

 

[jhendr3702]

that is crazy... Jeff knows way more about those bikes than i ever will ... for sure.. if i had to choose my advise or his... i would take his...

i have one of those yz needles and the cek i think still in the carb that came off my 01... if you want it, pm me your addy and i will send them to you..

 

[webmaster]

My idle screw is nearly buried and the air screw does have little effect. I swapped in the 42/172 and put the needle in the second clip position myself after much experimentation, it was previously 48/175 3rd clip. It would idle until the tank ran dry with the original jetting, but would burble like crazy at almost every throttle opening. Like jhendr3702 pointed out, my needle is silver in color as opposed to brass, so I fully believe it to be original to my bike.

Yep - that sounds like stock '01 jetting - which is *crap*...

My guess is that you will be one very happy man after you get done fiddling with it.

jeff

 

[Jakobi]

G diameter seems to be the win on the older 300's. I haven't had any experience jetting an AS1 kitted bike personally so all here say. Not sure what kind of variances in crank case volume, port timing, etc are at play with the 01's either. Seems to be some good advice above though.

 

[webmaster]

i would agree with Jeff... when i picked up my 01 is was like yours.. nubbs still on the tires and almost 8 years old..
it had a n1ee 35 pilot and i dont remember on the main.. i talked to les also he told me that was oe jetted for that year..

is the needle in yours brass colored or silverish ? i ordered one of his jet kits and am pretty sure the needle was brass... the n1ee was silver

funny thing is mine ran ok for almost a year with that setup.. we are about the same altitude.. we had a pretty big temp/humidity change one year and it would barely run..

I know why it ran like crap with your environmental change. With the bad oem needle - you get pushed into going way lean on the pilot (35 in your case) and turning the idle way up. Now your pilot circuit is not really providing the majority of the fuel (and air) at idle/low speeds - the majority of the fuel is delivered by the nozzle/needle at idle/low rpm instead of the pilot circuit in the carb. So now your fuel (and air) at idle and off idle is "more controlled" by the Idle Screw instead of the air screw... (the reason why I asked if the air screw had little effect above...)

In this mode of operation - your are on the "tip of a needle" in terms of your fuel/air mixture - an environmental change might cause your mixture to go off - and in this situation the air screw can't be used to dial it in for that particular day - so no way out from there...

One thing that is key - whenever you are switching from the oem jetting to something closer to correct - always re-set the idle screw to a more reasonable position... it shouldn't be cranked in to the point of the spring being coil bound. You need to get the slide and needle back down so that the slow and mid circuits in the carb are properly separated - then and only then can the pilot and airscrew be effectively dialed to get you in the sweet spot. Note that this usually means using a richer pilot than what was used with the oem jetting - if I see a 35 pilot, I think something is "off".

jeff

 

[Jakobi]

+1 for webmasters explaination!

Another thing to consider with this is the actual length of the straight section (before the needle starts to taper). The N1Ex OEM needles have a really short section compared to say N3XX or NExx. This also reduced the window in which you can adjust the idle speed before it ends up on the taper and causes the issues explained above. The N1Ex OEM needles also have a super rich first taper which adds to the issue.

 

[jhendr3702]

I know why it ran like crap with your environmental change. With the bad oem needle - you get pushed into going way lean on the pilot (35 in your case) and turning the idle way up. Now your pilot circuit is not really providing the majority of the fuel (and air) at idle/low speeds - the majority of the fuel is delivered by the nozzle/needle at idle/low rpm instead of the pilot circuit in the carb. So now your fuel (and air) at idle and off idle is "more controlled" by the Idle Screw instead of the air screw... (the reason why I asked if the air screw had little effect above...)

In this mode of operation - your are on the "tip of a needle" in terms of your fuel/air mixture - an environmental change might cause your mixture to go off - and in this situation the air screw can't be used to dial it in for that particular day - so no way out from there...

One thing that is key - whenever you are switching from the oem jetting to something closer to correct - always re-set the idle screw to a more reasonable position... it shouldn't be cranked in to the point of the spring being coil bound. You need to get the slide and needle back down so that the slow and mid circuits in the carb are properly separated - then and only then can the pilot and airscrew be effectively dialed to get you in the sweet spot. Note that this usually means using a richer pilot than what was used with the oem jetting - if I see a 35 pilot, I think something is "off".

jeff

that makes perfect sense Jeff.... I had never seen a 35 pilot before that bike..

 

[TheLetterJ]

A big thanks to jhendr3702!

i have one of those yz needles and the cek i think still in the carb that came off my 01... if you want it, pm me your addy and i will send them to you..

I received the needles you sent yesterday, that was very generous of you, thanks again!

I put the CEK in on the second clip and set the air screw at 1 1/2 turns as a baseline then took it for a rip down the road to warm things up. It actually pops the front end up without having to "yank" it up, so definitely a step in the right direction. I pulled back into the garage to start tinkering with the air screw and idle screw and I noticed exhaust exiting near the front of the engine... uh oh. Upon further inspection I found that I had a new dent along with 2 cracks in the pipe about 6" from the exhaust flange. I'm not sure exactly when that happened, but it was extremely rocky on my last ride so I'm sure it's from last weekend.

I'm sure that a cracked/ leaking pipe would not do me any favors getting the jetting dialed in so I pulled the pipe off and brazed up the cracks... hopefully that will hold well enough. I figured that the annealed sil-floss joint stands a better chance of survival than a welded joint on the pipe since it's likely to get smashed again! I took a peak in the cylinder and was surprised to see that everything was in excellent shape, with just a miniscule trace of blow by above the bottom ring. I'll likely rering it when I pull the topend down to set my port height/timing and have the head cut this fall.

I still need to tweak the pipe a little before buttoning it back up but I have high hopes that the needle change will give my bike that little "pep in its step" that I was looking for.

 

[jhendr3702]

that is great... glad to help..

i have learned so much on this forum.. i think someone on here gave them to me..

 

[jefgil123]

Do the R B Designs squish band, get it down to .045-.050 " from the piston crown.
It will lift the front with ease.

The CEK, or CCK is great on the 2001.

For your terrain, take the shim(s) out from behind the power valve clutch spring. Then absolutely no hit, but still all the power.

A 36mm Carb is a possibility...

 

[TheLetterJ]

Yep, that's happening right now. The engine is apart (still trying to source a "C" piston) and I will send the head off to Mr. Black as soon as I get the jug bolted back down. I didn't mention it here, but I did replace the pipe last year after failing my attempt to repair it.

I have a 36mm PWK on my KX125 (needs top and bottom end rebuild... still weighing my options there) that I could borrow if I feel the need, but I'll get it dialed with the 38mm first and then (maybe) see if improvements can be had by going to the smaller carb. The divider plate mod on the 38 has me curious though.

I've never played with different slides/ cutaways/ notches since I have yet to wrap my head around what difference they make. If someone is bored and cares to explain it to me, I'm all ears.

I was pretty happy with CEK 2nd clip, 172 main and back and forth between 38 and 40 pilot. I was a little hesitant to run the 38 pilot as that just "seemed" like it would be lean to me, but the air screw actually did something with the 38 installed, it was pretty much wound all the way out with the 40 unless it was balls cold outside.