Taffy & LarryCO Jetting


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.


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!


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


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.

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!

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.)


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.



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.

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!

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



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.


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?

how about smack in the middle!

try that :)


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 :)


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


You Rock! :)

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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