Jetting By Sound

[JP4]

I've seen posts where guys pass jetting judgment based on the sound from a a vid. I'm happy with my set-up, but curious about the the sound I make?

http://www.youtube.com/watch?v=ohFK2...ature=youtu.be

Currently ~800' ASL, <15C temp.

The specs:

2010 300 w/ AS1:

40 PJ
1.5 AS
JD Blue - 3rd clip
178 Main
#7 slide, with cut out (stock)

I race/ride tight woods single-track, and like a set-up that pulls strong through the bottom and runs smooth and stout through mid-song. Screaming up top is not really useful to me.

I've been through a bunch of needles and set-ups, and this is the best yet.

Have a look and send your critiques.

Thanks,

Jason

[Jakobi]

Nice vid Jason.

I'm not so keen on jetting by sound/video as I am by feel, as the mic on different cameras can give some very different results. From yours though I see no sign of hanging idle, no dinging or banging on decel, a slight burble at light throttle that clears up instantly under load. It doesn't sound rich thats for sure.

Hows the fuel economy? The AS1 appears to respond really well to the richer needle diameters.

[GMP]

JP4,

The JD Blue in the AS1 is awesome. Your in there! I'm a little richer on the main and pilot but I'm on a 250. Getting rid of the Stealth and going to a straight silencer really helped as well, more than I thought it would.

[n_green]

Originally Posted by GMP

JP4,

The JD Blue in the AS1 is awesome. Your in there! I'm a little richer on the main and pilot but I'm on a 250. Getting rid of the Stealth and going to a straight silencer really helped as well, more than I thought it would.

In what way does changing the stealth for a straight silencer help? More/better torque/top end?

[GMP]

I think it improved the low to mid. I changed it for other reasons but the bump in torque is an added bonus. I used a Cannon Racecraft silencer. The core dia is slightly bigger than an FMF or Messico, perhaps thats what helps. On my '07 the Stealth felt the same as my Messico silencer.

[JP4]

Originally Posted by Jakobi

... Hows the fuel economy? The AS1 appears to respond really well to the richer needle diameters.

I get 80 to 90KM out of a tank, so I'd say that's thirsty to average.

I have to agree with GMP that the JD Blue rocks in the AS1. I've tried a bunch and found the NE.. and N3.. needles too lean off the bottom. The JD blue seems to pull much better in the first quarter throttle area.

In the hot weather (+25C) I ran the clip in the 2nd position, and started with the 42 PJ. However, as the throttle response got better with the A/S at 3 out, I downsized to the 40 PJ. I should try the 42 now that I'm riding in temps <10C.

Tried the JD Red in the hot and cold temps, but I much prefer how the bike runs with the Blue needle.

As an aside ... I've spent some time on a friend's '12 Berg TE300, and I'm surprised at how different the bikes run. His bike is nicely jetted, but the engine seems to spool up much quicker than the Gasser. And not always in a good way. It's fun to ride, but can be uncontrollable at times in the tight stuff as one little jar to the front end can lead to a big whiskey throttle. I'm thinking the GG has a heavier flywheel or ignition or both. I'm not saying the Berg is bad, just seems to deliver power in a very different manner.

I think I hijacked my own thread ... oops.

[Jakobi]

How would you describe the reds characteristics compared to the blue?

I actually tried a NAFW#2 (Kawi needle) in the Gasser today. Very rich first taper. Too rich. Stuttering and breaking up everywhere with a hard hit as it cleared onto the next taper.

I'm still loving the AS2 with the N3CJ needle. I find it somewhat hard to evaluate the difference between not producing max torque and simply being in the wrong gear. As someone who like instant throttle response and a crisp snap bark that rips through the rev range I'm happy to sacrifice a little torque to gain a more free revving engine. When I go for torque I find it feels wet and doughy, the spooge follows, the smoke billows, and the bike wants to flame out whenever the throttle isn't open.

[GMP]

Then your not on the mark. The JD Blue in all my bikes did/does none of that, except some spooge from a spark arrestor but thats fine. It just pulls hard off the bottom, moderate mid hit, and revs out nicely. Wheelies at will off the throttle, no clutch. In ALL cases, playing with the leaner needles, I got real crisp snappy throttle response unless there was a load on the bike, then it felt flat. I suspect that with a 300 though, you can get away with more of this than with a 250, but in general I don't like the bike running borderline lean anywhere just to achieve a certain power characteristic.

[Jakobi]

You basically described what I get running what I am now Glenn. Just good strong power everywhere. I can pull the front end up in 6th gear no clutch (when on song). It will lug down to zero a gear high and keep pulling, if it does start to bog right down a touch of clutch brings it right back to where it needs to be.

If I go too lean I can definitely feel the power fade off and notice that it takes more clutch work to get the same results. It just amazes me how much difference there is between the AS1 and AS2, particularly at smaller throttle openings.

[GMP]

Thats why we have to be clear when giving advice to people who are new here. The ASII obviously has a larger signature, perhaps this also makes changes like needle dia, position, pilot, etc. have more relative effect than the ASI (makes it more "touchy" to jet). It makes sense if you think about it.

Anyway Jake, hopefully this spring this will all go the way of air cooling and twin shocks.