Needle recommendation?

[IcutMetl]

I was doing some tuning on my carb today, and made some pretty good progress. I currently have a bored 38a/s on a 67.5mm midrange ported 195+psi top end, open airbox, FMF pipe, airscrew 1.5 turns out, RAD valve, etc. You can def. tell that the meat of the power is in the midrange; it doesn't pull like a tractor off the bottom, and it's not ALL top end either. Seems to start fine, and will idle pretty damn smooth too. Never had a problem fouling plugs.

Started out with 175 main, 48 pilot, DDJ needle on middle clip. Ran good but there was something missing. Had a slight stumble off the bottom, and seemed to stall early. Choke would cause high idle instead of stall. Put a 50 pilot, then a 52- didn't see a HUGE difference either way. I don't have any leaner than a 48. Choke would kill engine, but it took a few seconds. Messed with airscrew- 1.5 to 1.75 turns seems to be the smoothest but hard to tell.

Played with my main a bit; tried putting in a 178- ran good with no sputter or bog, but felt flat on top- better with a 175; may try a 172 just to see what the plug looks like.

Played with my needle; started in middle, then tried 1 clip down (4th). Definite change; not better- had a sputter. Went to 2nd clip- much more responsive; better off idle response. Then tried 1st clip- best yet- I would like more off bottom response, but it's not a bottom end motor either. Throttle response is cleaner all the way thru and it likes to wheelie shifting thru the 1st few gears.

Being I'm at the top clip on my needle kinda makes me think I need something a bit leaner to play with? I have a CEG and a CGJ to play with; should I be looking for anything specific?

What do you recommend for my pilot? Hard to tell if richer did anything for me; didn't seem to affect it too much. Should I try a 45, or keep going richer.

I started out on a used plug, which was a milk-chocolate brown after a full-throttle shutdown. I typically gap around .018", and it definitely seemed to run cleaner on a fresh plug, but didn't have enough time to really burn it in.

I know I'm close...messing with the needle really helped it a ton. Just a little fine tuning and it should be breathing fire again. This massaged airstriker sure seems to suck the fuel down faster than my 38PJ did though!!

So what do ya think?? I appreciate the help!!

[250rPRIDE]

if your not all top end, like your port pipe ect.. a 172 or 170 main wouldnt hurt, pilots arnt all that picky they are hard to get perfect from my experiance, but i would go a little leaner, but it sounds like your close. i would change the needle if i was you

[IcutMetl]

That's what I think I'll try- go to a 172 and see if I pick up a little extra zing and see how the plug looks...if it burns too light I'll go back to the 175. Seems to always look chocolate brown when I take it out.

I wish I had a 45 pilot to play with; I'll have to get one. It didn't seem to change much at all going from the 48 to the 50 then the 52.

Any recommendations on a different needle based on what I've been experiencing?

Thanks for your help!

[IcutMetl]

Just ordered a 42 & 45 pilot, plus a DGH and CEJ needles. We'll see how those work when they come in.

[250rPRIDE]

go with the dgh. start on the middle clip

[hondamancbr03]

Not sure if this is apples to apples but i'm running a 350PV motor with the 38A/S and 210psi.....I too had the rich stumble off idle with the DDJ needle in the middle and a 175 main, but the middle and top was great. I called Arlen with LED since it's his build and he said to try the DDK which will only lean out the idle to 1/4 and leave the mid and top they way it currenlty is........I'm going this weekend to try it out so hopefully this will be the jetting i've been looking for.

[IcutMetl]

Let me know how it works out for you. Yours seems to have the same characteristics as mine. What sucks for me is that I've never ridden another 'R other than mine, so I have nothing to compare it to- running better or worse.

[hondamancbr03]

I did forget to mention that on my last riding trip I was frustrated with the bottom end stumble so I went to local dealership and tried to find the DDK needle and found that they are special order, they had a CEK which is leaner throughout the entire needle to 3/4 throttle....It made a big difference, the bottom stumble was gone and I just kept an eye on my water temp. So as long as your port timing isn't set to high you can jet out that stumble. Do you have a DEK needle? I'm going to try that one as well.....It looks good on the chart for my engine.

[IcutMetl]

Naa, I don't. First I'll try the DGH, then the CEG/CEJ...feels like it's close, but my plug still looks a little bit dark and the butt dyno tells me there's still a little bit left to be had.