I need jetting help....

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Went for a quick squirt today on a local testing area. Only a small 35 k loop in an area with more rocks then dirt. Pretty technical area pure 2nd gear maybe 3rd on occasion territory.

First up temp was 20 deg C with humidity at 66%. Riding approx 200m asl.

Started the bike and she was lean, no real surprise having previously set it up at 44 deg C with 20% humidity lol.

Had to go up a pilot size straight away and even then with a 42 pilot the air screw was at 1 turn out. I went up to a 180 main as well to be safe, probably didn't need it, as I said this area isn't a WOT area at all.

The torque off the bottom wasn't affected as much as I thought, a bit more clutch required but it would still pull down quite well in 2nd and even 3rd. I love the mid and top end in this thing now, so fun :D

Only thing I'm unhappy with was the economy, 5.2L fuel used for 35k's. With that economy I'd be lucky to make it 65k's on a tank! :mad: There were a few lay downs and I dumped a fuel bowl when changing the jets but that wouldn't have used that much fuel.

Dunno, I'll try it again on another normal loop over 60 or 80k's if I make it and see if it was just the technical area making it thirsty.

This is still a massive thorn in my side, why the hell is this bike so thirsty. :mad:
 
That sucks hairys. Seems the extra fuel is the price of the extra torque. :eek:

I'd probably go back to the float height now and see if you can drop the fuel level another mm or two without running dry on WOT runs. Ando reported decent increases in economoy doing that. Mind you his 300 was running something like 38 N3CH#2 175. I find the economy is in the needle position, but it does exchange torque for response. A half a clip pos change is the difference between my bike having to turn to reserve at 85kms after putting an extra litre in, or being able to drain an extra litre from the tank to donate after not using any extras at the same place. Same trails. Faster pace the day it ran out too though. Still a big difference.
 
Ill have another look at my float, though it was set at 8.5mm, could adjust it a bit more I guess, it was set at over 10mm when I bought it!

Never starved of fuel, though it had a 180 main with stock N1EG needle in the 36mm carb haha.

Think ill try the N3EW needle but will use the correct sized pilot for it this time. Re reading my notes I didn't mind that needle at all, and based on yesterday's run I think the H needle is borderline in that the bike probably wanted a richer diameter needle with leaner pilot or alternately leaner diameter with richer pilot. I didn't like the G needle so will give the W a go.
 
I was also getting ok economy using the JD red needle, just didn't like the loss of torque off the bottom, it doesn't seem like these N3 needles are as prone to sacrificing torque despite the lean starting diameter.
 
If you haven't already, you could try going leaner on the needle pos again and see how it feels through the lower to midrange, IE N3EH#2. My 300 liked N3EW#2 in the winter and N3CJ#2 in the summer months. Mains would vary between 172 and 178. As a 250 my bikes prefered richer needle positions, but still feels as clean and crisp as the 300 was.
 
Just got back after 3.5 weeks away for work. Plan on riding this Thursday though I'm only armed with the N3CH so ill run it in clip 2 to see what diff it makes.
I ordered NEDH, NECH, N3CW, N3EW, N3EH from those sites you directed me to so the fun will begin when they arrive.
 
Jakobi said:
Deadly! Hold onto that bike with the N3CH#2. She'll hit like a freight train!
Click to expand...

Yep, it hit hard, real hard. Quick squirt today with it in clip #2, wow. My arms and hands were cramped after 1 x 1.5k lap of a little training circuit we have, lots of rocks and a little rocky hill climb at the end. Usually it's ok but I was struggling to hang on the whole time. Haha. It was either spinning, wheelying or both. Fun, but not for trail riding.
I felt better though so the in between needle may be the trick. That would be N3EH #2 yes?
 
:D :D :D

Spot on. In order from rich to lean in half clip adjustments.

N3CH#3
N3EH#2
N3CH#2

You should see a decent improvement in fuel economy moving to that too. At least closer to 10km/L anyway.
 
Fuel economy was better in clip #2, 2.9L used for 23k's. So 12.6 L per 100k's or 70k's to a tank. Still not brilliant.
 
Went out for an 80k loop on Sunday - 1100m asl, 15-18deg C, 65 - 75% humidity.

I swapped out the N3CH as it was too rich in clip 3 and to savage in clip 2. I've been thinking for a while now this oval bored card seems to like a leaner diameter then the non-modded 36mm did so I threw in a JD Red (only W diameter needle I had) in clip 3 and kept the same jetting - 178 main, 42 pilot AS - 1TO.

I ran this jetting for 30k's until we had a break then I had to change it, it was very rich through the mid and top end and was taking forever to get on the pipe. Jake you've spoiled me by introducing me to the N3XX needles, the JD needle is well boring in its power delivery.
After 30k's I was down to about 5L in the fuel tank so had used 4.5ish litres, not good. Added 1.5L from the backpack which took me back to 6L and dropped the needle to clip #2, also dropped the main to a 175.

Much betterer with this jetting, was clean and torquey off the bottom had a nice meaty hit through the mid (still boring compared to the N3XX needles though haha) and revved out nicely into the top end.

After 20k's or so it was lunch and during that time I swapped the pilot up to a 45 AS-1.5TO. The 42 had been fine and didn't feel lean at all but I noticed that the bike seemed to be running on after working hard. It did exactly the same thing with the 45 pilot in, turns out the bike just idles better with the leaner needle diameter in it and the slide, having been set up to idle on the G and H dia needles was too high resulting in a fast idle with a W dia needle in it. I figured that out at the end of the ride though so didn't fix it during.

Finished the ride bang on 80k's, and hadn't hit reserve yet but I would have been bloody close so I managed to do 50k's on about 4.5 - 5L which is acceptable economy.

Here's a vid from when I was running 45p, JD Red #2, 175m:

http://youtu.be/sdWwxiZheNU
 
Jakobi said:
:D :D :D

Spot on. In order from rich to lean in half clip adjustments.

N3CH#3
N3EH#2
N3CH#2

You should see a decent improvement in fuel economy moving to that too. At least closer to 10km/L anyway.
Click to expand...

Quick Question
Rode my bike on Saturday.
At end or ride there was black junk/spooge coming out of back of muffler....
Any input....

Here is what I have
2012 300
Riding Elevation was around 2500 ft
Outside Temp = 45 degrees
Main Jet = 178
N3CH needle at 3 clips town from the top.
Fuel Mixture. Motul 800 at 50:1
 
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Just a bit of spooge. Its good to know you have oil coming through the engine. That big ol FMF Q silencer is meant to be really good at trapping it and allowing it to dribble out. If thats all that the issue was, and the bike was running good just get a bit of rag and give its bum a wipe. Motul 800 also has a high flash point which means also contributes to a bit more unburnt oil in the exhaust. Good lubrication
 
Bike did run great!!! So I will leave alone.
But curious....Once snow melts from single track trails in the Cascades here there will be times we are over 4000ft.....
Do you think these settings will be ok?
 
You might find it feels a bit richer, but I doubt that will cause any issues. What sized pilot are you running with the N3CH? Usually for a 300 I find that a 42 pilot and J diameter needle is just a bit cleaner off idle.
 
I will have to check the pilot size. For some stupid reason I did not write out down.
When you say "J". I am guessing you are referring to N3CJ
THANKS
 
Jakobi said:
You might find it feels a bit richer, but I doubt that will cause any issues. What sized pilot are you running with the N3CH? Usually for a 300 I find that a 42 pilot and J diameter needle is just a bit cleaner off idle.
Click to expand...

While total clean up of bike had the carb off.
The pilot = 40
The bike seems to be running a bit rich. The spark plug was rather black as well.
I am thinking I will raise 1 clip (from #3 from top) on my N3CH Needle to clip #2 (from the top) in return hoping to lean it up a bit.

You had mentioned a #42 pilot......wondering if it is worth changing to the #40...?
And the N3CJ Needle you mentioned....What will that do for me?

Thanks for you help and input!!
 
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Definitely, try changing the needle clip position and evaluate the changes. It may be just what you're looking for. If it ends up feeling better off the bottom but too lean in the mid range, then you're probably better off moving to a leaner diameter needle which will clean up the bottom and keep the rest the same. If you go to a leaner needle diameter you'll need to increase the pilot to keep the same idle and off idle mixture.

The main thing is to just adjust one thing at a time and see if its better or worse.
 
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