TRX250R.ORG

Workshop => Carburetor, Intake, and Exhaust => Topic started by: dirtyd on May 25, 2015, 07:57:53 PM

Title: needle help
Post by: dirtyd on May 25, 2015, 07:57:53 PM

Just need the pros to help confirm what needle I should try next. Right know I have a DGH needle and have to run it in the richest clip pos. #5. The quad was lean at about 1/2 throttle when in the 3 and 4 pos. when under load. Once it got past this hesitation it ripped. Went to the #5 pos it it ran good through out the rpm range. I read the Keihin jetting guide section on here from rsss396 (great info by the way, thanks) and it looks like I should change needles to be in the 3rd or 4th pos. So after studying the chart should I try a DCH to get back to the middle positions for the clip? Or do you recomend another needle?

Title: needle help
Post by: dirtyd on May 26, 2015, 09:12:12 PM

76 views and no replys

Title: needle help
Post by: supernutt on May 26, 2015, 09:53:08 PM

I like my CEL needle.  At least for summer riding.  I change them out for the frozen months but I don't remember the letters on that needle.  But according to the jetting chart, that would be the logical choice for your next needle to try.  I am no expert but have tried many different needles.

Title: needle help
Post by: Usmoneylover on May 26, 2015, 09:58:27 PM

An "E" length needle should get you back to the middle position.

Title: needle help
Post by: dirtyd on May 26, 2015, 10:12:49 PM

was thinking about the DEG and also the DDJ. Not sure on the C** needles since those are a leaner taper which controls the 1/2 - 3/4 throttle and thats were my lean condition was.

Title: needle help
Post by: havinnoj on May 27, 2015, 11:16:07 AM

For reference, post #12 on this sticky should help:
http://trx250r.org/threads/2770-Keihin-Jetting-Information-amp-Guide-TRX250R (http://trx250r.org/threads/2770-Keihin-Jetting-Information-amp-Guide-TRX250R)

Title: needle help
Post by: dirtyd on May 27, 2015, 06:57:19 PM

Yes already read that. But it would seem very odd to me to go to an E** needle as i havent ever heard or read anyone using them. The DGH i have maybe fine when warmer weather as it was mid to upper 50s.

Sent from my ZTE V768 using Tapatalk 2

Title: needle help
Post by: Usmoneylover on May 27, 2015, 07:28:52 PM

I am using a DEL needle on the middle clip right now....Was in the 4th clip when the weather was around 60

Title: needle help
Post by: Usmoneylover on May 27, 2015, 07:30:29 PM

I just read your post it's not an E** needle, it's a *E* needle.  You would need a DEH...you might try a DEJ also.  I'm not an expert tuner but I felt that my engine was too zingy with a C taper.

Title: needle help
Post by: dirtyd on May 27, 2015, 10:02:41 PM

No I was talking about the E** (richer taper). I know what your saying but Keihin does not have a DEH according to their list of needles. Thats why I was thinking the DEG, same taper but shorter length but its a a tad richer 1/8-1/4 throttle. I  was origanally thinking the DCH but wondering if it would be the opposite problem I have right now and would be running that on the top pos. because it might be to rich of a needle. Thats was the whole point of this thread becase I don't have enough experience with meesing with different needles to know how much change there is in them. Alll in all who knows but the DGH might be right when its above 70deg and just not when its 55deg. The next chance I get to ride it should be at least above 70.

Title: needle help
Post by: Usmoneylover on May 27, 2015, 10:17:40 PM

What pilot and main are you running?

Title: needle help
Post by: dirtyd on May 28, 2015, 06:27:27 AM

180 main and 50 pilot

Title: needle help
Post by: rk88r on May 28, 2015, 06:50:59 AM

I'm not a pro,but I think you are on track. The "l1" changes the length one groove per letter. The dch should be equivalent to move up three grooves. I'd try a dej first though it seems to work well for me in several R's.

Title: needle help
Post by: Usmoneylover on May 28, 2015, 08:44:27 AM

Quote from: rk88r;54759

I'm not a pro,but I think you are on track. The "l1" changes the length one groove per letter. The dch should be equivalent to move up three grooves. I'd try a dej first though it seems to work well for me in several R's.

Wouldn't that put a DCH 2 clips richer than the 5th clip of a DGH

Title: needle help
Post by: Tbone07 on May 28, 2015, 11:34:41 AM

Try out the DEG. That's what is in mine and it runs clean

Title: needle help
Post by: Jerry Hall on May 29, 2015, 02:02:10 AM

Here is a quick reference chart I made years ago.  If you are at the richest clip position and want to make it richer, the chart will allow you to look for an equivalent needle that will allow you to change the clip and make it richer.  The following chart was from an excell spreadsheet but it lost its formatting when imported to the forum.



[TABLE=width: 677]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD=colspan: 6]Keihin Needle Clip Comparison Chart for N427-48 Needles[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD]      [/TD]
[TD=colspan: 6]           For:   PE,   PJ,   PWK,   PWM   Carburetors[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]L1 = distance from top clip position to 2.515 mm diameter.[/TD]
[TD]L1 Designator C = 36.35[/TD]
[TD]L1 Designator D = 36.80[/TD]
[TD]L1 Designator E = 38.15[/TD]
[TD]L1 Designator F = 38.60[/TD]
[TD]L1 Designator G = 39.95[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]Clip Position[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]Top 1st   [/TD]
[TD]36.35[/TD]
[TD]36.80[/TD]
[TD]38.15[/TD]
[TD]38.60[/TD]
[TD]39.95[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]2nd   [/TD]
[TD]35.45[/TD]
[TD]35.90[/TD]
[TD]37.25[/TD]
[TD]37.70[/TD]
[TD]39.05[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]Middle  3rd   [/TD]
[TD]34.55[/TD]
[TD]35.00[/TD]
[TD]36.35[/TD]
[TD]36.80[/TD]
[TD]38.15[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]4th   [/TD]
[TD]33.65[/TD]
[TD]34.10[/TD]
[TD]35.45[/TD]
[TD]35.90[/TD]
[TD]37.25[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD]Bottom  5th   [/TD]
[TD]32.75[/TD]
[TD]33.20[/TD]
[TD]34.55[/TD]
[TD]35.00[/TD]
[TD]36.35[/TD]
[TD] [/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD]Example:[/TD]
[TD=colspan: 5]You have a DGH in the 5th clip position and would like to be able to make[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD=colspan: 5] the DGH richer in the 1/2 to full throttle range.  L1 for the DGH in the 5th clip[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD=colspan: 5]position is 36.35 mm.  A DCH in the 1st clip positon would be equal to a DGH in[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD=colspan: 5]the 5th clip position.  A DEH (if it existed) in the middle position would be[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD=colspan: 3]equivalent to a DGH in the 5th clip position. [/TD]
[TD]

[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[/TABLE]