1/8 to 1/4 Throttle weirdness

[hawaiidirtrider]

I was trying to describe or place the sound the bike made in the throttle range after a slower luggy trail ride with the same sound that happens during warmup in the same throttle range. Of course the bike is going to run different when cold, not trying to fix that. Just making notes as I go. Sorry if it isn’t concise.

Im just trying to figure it out with you...The reality is we are thousands of miles away from each other and we are just guessing.. trying to guess right but guessing. If we heard and rode the bike ot would be much better but it’s pretty cool that we can talk Dirtbike even if imperfect.

[aj_mariner]

I agree...but it is pretty wild that I could make it do the same thing on the N2ZJ with a hot engine

Bought a #6 slide. Will see how it goes.

It looks like the slide mod that KTM/Husky guys are doing is to fix a rich spot in the same area. Their Mikuni’s use a #4 slide.

Further down the rabbit hole...

[aj_mariner]

Goodies from Jets-R-Us came...

7B807D67-8568-472C-B085-1D737E0ACA57.jpeg (83.25 KiB) Viewed 8201 times

[aj_mariner]

Took her out for a spin with the #6 slide in and had to increase idle mixture screw nearly a 1/4 turn to keep her from dyin. Does everybody’s #7 slide have the notch in it? Picture comparisons online have other #7’s without the notch...hmmm

[firffighter]

So, I hestiate in jumping in, but I've been down this road many times on many bikes. If you want completely perfect linear power delivery with no fuss, RB Designs is the ultimate solution. Do some research and you'll be shocked at the results. Head and carb mod are very reasonable and turn around is usually 2-3 days. Ron's been in the game for decades and you won't find a more precision piece of workmanship when completed.

I can tell you my brother's 250rr is the best jetted 2-stroke I've ever ridden and I've owned and ridden too many bikes to count!

[aj_mariner]

Thanks for the tip. It’s kinda fun trying to get it “how I like it”. It’s just a bit annoying when I can’t ride on the out of norm days to dial in that temp since the kids are on summer break, too young to stay at home by themselves and I have to be Mr. Mom

[aj_mariner]

So, the notch is key. #6 slide straight from Jets-R-Us doesn’t have it, and am betting they will all come without. It threw my idle off so the bike shut off when not on the gas. The notch also helps broaden the idle mixture screw’s range of RPM adjustment. I had to turn in the IMS almost all the way to achieve the same idle as before, and felt like I lost some low end grunt. The non-notched #6, as well as the BR7ES did allow me to get down to a 38pj with AS @1.5 turns out on an 84degF day at 1500’...and not knock. Turning the air screw all the way in killed the engine with both the NECW and NECJ so I knew I wasn’t too lean.
As far as it smoothing out the lean spot, jury is still out. I plan on getting a #4 and/or #5 to test against the #7 so the differences are easier to feel and know it isn’t a placebo effect. Whichever slide works best for me, I plan on notching it just like the OEM slide.

[hawaiidirtrider]

So, the notch is key. #6 slide straight from Jets-R-Us doesn’t have it, and am betting they will all come without. It threw my idle off so the bike shut off when not on the gas. The notch also helps broaden the idle mixture screw’s range of RPM adjustment. I had to turn in the IMS almost all the way to achieve the same idle as before, and felt like I lost some low end grunt. The non-notched #6, as well as the BR7ES did allow me to get down to a 38pj with AS @1.5 turns out on an 84degF day at 1500’...and not knock. Turning the air screw all the way in killed the engine with both the NECW and NECJ so I knew I wasn’t too lean.
As far as it smoothing out the lean spot, jury is still out. I plan on getting a #4 and/or #5 to test against the #7 so the differences are easier to feel and know it isn’t a placebo effect. Whichever slide works best for me, I plan on notching it just like the OEM slide.

Why are you getting a 4 or 5 slide now? to make it more rich???

[HRRacing]

This has always been my go to jetting bible.

[aj_mariner]

Yes, more rich. And yes, that pdf is great...thrown that around several times on here.