Taffy & LarryCO Jetting

56 replies to this topic
  • tctrailrider

Posted June 18, 2003 - 01:34 PM


Taffy disabled the ACV all through his jetting tests. I have not. I have done the BK mod and have changed the squirt duration while testing and find that very, very short works the best. My guess is 1/4 second.

  • Taffy

Posted June 18, 2003 - 11:06 PM



you may have noticed a difference in the exhaust note when changing needle straights, you will certainly have noticed a difference in choke duration. the 'M' and 'N' will sound like there's a rag over the tail compared to the 'P'.

your PA is at #75 but to compensate you have gone 1.5-2 turns on your PS but i'm sure you realised this.

i think something still isn't right for your needle to be that low but from here the changes are so suttle and only you can make the call as to what feels better and what doesn't.

well done!


  • Eagle426

Posted June 19, 2003 - 04:01 AM


STUPID QUESTION #639527- Where do you suggest getting new jets? Do you go through your dealer or is there some place better?

  • tctrailrider

Posted June 19, 2003 - 05:45 AM


Some dealers are pretty good with jets most are terrible. I have ordered a fiew times from Sudco.com. Service has been good. Haven't needed part numbers and allways got what was ordered.

  • Eagle426

Posted June 19, 2003 - 06:30 AM


It was recommended to me to try the EKN and EKP needles. However, when I called sudco, they do not carry any EK* needles at all, I guess that I will try my dealers!

  • Pooley

Posted June 19, 2003 - 09:59 AM


By the way, needle OBEKN #5JG-14916-EN-00 is listed as an EVN needle on the parts fische at the dealer. Just use the above #, I did and got the right one.

This setup is awesome! I haven't tested it in the woods yet but its been great terrorizing my neighborhood with snap wheelies :). (The little kids really dig me, not the parents though...go figure :D.)

  • LarryCO

Posted June 19, 2003 - 12:40 PM


They might not carry the "EK..." needles, but they do carry "EJ..." needles...which are the same thing except for being 1/2 clip position richer. Thus, you can go with these and compensate by using a very thin washer to "raise" the needle up slightly.


  • tctrailrider

Posted June 19, 2003 - 02:40 PM


Per your tip to try EKN and EKP needles. The E is the taper angle. The N and P are the straight diameters. Letter o is not used. As the letter gets higher in the alphabet it gets leaner. The --N is one step richer on straight that the --P, ( O is not used). Middle letter is clip position, each letter up is 1/2 clip leaner. EKN is one clip richer than EMN, so EKN2 = EMN3.

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  • Eagle426

Posted June 19, 2003 - 03:28 PM


Thanks to all for dealing with my idiotic questions! A group of us are heading for Hatfield-McCoy (WV) next friday, so I am somewhat pinched for time to get the parts, install them, and tune it!

  • James_Dean

Posted June 20, 2003 - 02:28 PM


Taffy and tctrailrider,
Interesting discussions and results. It's good to see the jetting changes were successful and nice job checking everything.

Sudco has brass needles that are 1 clip leaner than EKM, EKN, and EKP. These are EMM, EMN, and EMP.
EMM#4=EKM#3, EMM#3=EKM#2...
EMN#4=EKN#3, EMN#3=EKN#2...
EMP#4=EKP#3, EMP#3=EKP#2...

Only Yamaha or Honda have the OBEK- and OBEL- (plated)needles
Sudco has OCEM- (brass) needles


  • tctrailrider

Posted June 23, 2003 - 07:02 AM


Got in a short ride this weekend, jetting in my signature. It runs great, starts great. No popping, missing or bangs. Tried EMP4, a little missing around 1/4. Cleaned the carb, checked float level, all good. The only way I will be able to get the needle higher is to go leaner on the straight. May at some point try E-Q. My theory is with the Powernow I have to jet leaner on the needle. Anyway, this setup is wonderful, thanks for the help.

  • larsonsenza

Posted June 23, 2003 - 11:05 AM


If I use my ELN needle and go with TcTrailriders settings 158mj, 160maj, 38pj, 60pas, and fs 1.5, were should I put my needle clip?

  • Taffy

Posted June 23, 2003 - 12:49 PM


how about smack in the middle!

try that :)


  • Guest_Guest_*

Posted June 23, 2003 - 01:54 PM


If I use my ELN needle and go with TcTrailriders settings 158mj, 160maj, 38pj, 60pas, and fs 1.5, were should I put my needle clip?

Start at 3 :)

  • tctrailrider

Posted June 25, 2003 - 03:43 PM


Per your question about ELN and clip position, I think clip 4 would be great. I have a vortip baffle so my needle is leaner. Clip 4 should be on the money. Since my last post I have raised my EMP to 3 1/2 and 160 MJ, changes are now hard to detect, but this is so far the best. LarryCO and some others are running uncorked with your jetting with EKN4. ELN is 1/2 clip leaner so clip 3 should be a bit lean.
Good luck. Denny

  • TeamScream

Posted June 25, 2003 - 05:16 PM


You Rock! :)

  • tctrailrider

Posted June 29, 2003 - 01:52 PM


Another week and some more jetting tests. Went to the woods today with the jetting in my signature. I don't think it will get better than this. Everything from bottom to top is wonderful. Starts good hot or cold, no surging, pops or bangs. Throttle response is seamless and off bottom it is instant. The process was a pain but the result is worth it. Those who run a Vortip at around sea level may want to give this a try. Good Luck, Denny


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