1. anyone with a ported head running the same size jets on both sides?
2. anyone running different needle position from one side to another?
3. Airbox stumble? With the lid off only? I drilled (2)2 1/2 holes on the bottom of the box, (3) 2 1/2 holes on the back, (3) 2 1/2 on the left and (1) 2 1/2 on the right (exhaust pipe side) Air should enter from all directions now
4. Do they make jets bigger than 200? I am knocking on the door now with a 195 and feel i need to go bigger. Trying to get the dyno back to my house by friday. Trinity pipe runs the collectors all the way back to the pipe. Can i take the pipe off and sniff each side? Will it tell any thing? I had a plug check last week with 2 distinct sides.
5. Have i run out of carb with the stockers
6. How do you determine the correct octane needed?
7. I really would like to hear thoughts wether you have tried them or not. Sooner or later i hope to sort this out.
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3. I don't have a stumble without an air box. I don't know if that helped but there you go.
4. I wouldn't think that either side would be differnt. If it was how could you know what to change or what would you change to correct for this? Isn't there are swirl inside the combustion chamber? I would think that it would make things very difficult trying to sniff both sides. Check with Harley places if you are having trouble finding jets.

 

with 180/185 mains why not 22.5/25 pilots???

 

Blueleader-I am ordering 25 and 27.5 pilots to have on hand. We have gotten most of the head pipe glow out by adjusting the fuel air screws. It is lean on the very bottom end.

 

I am glad that i must be the only one with this problem.

 

14mins, sounds like you need some alone time at your drag strip with a box full of jets!

what exactly is your problem? lean on the bottom? put in 25 pilots.

 

14mins, Bring a box full of jets with you when you come to Atoka's test & tune next month & we'll try to get it straight.

 

Use your exhaust gas analysier as the best guide on what's lean where.

Upping the diameter - size of the needle jet (the tube in the carb body) increases total fuel flow. Mikuni make a truck load of needles, maybe it's a case of finding one with more flow in the region you are needing ? Get the code off the stockers and get the needle profile and diameters from Sudco and go from there.

What about using the DJ needles, these flow more fuel total than the stockers. Have you compared the two needle profiles, DJ vs Stock ?

Do these carbs have accelerator pumps ?? can't say i've looked at mine, can these be adjusted for more squirt earlier, often a low end stumble is due to a monetary lean mix when the carbs are wicked WFO, more accelerator pump volume often helps here. I know that the CV things are supposed to prevent this but ???

Thirdly are the carbs now been regulated by the needle jet into the float bowl, this shows up as a lean off with sustained high RPM regardless of main jet size.

Plugs can have a "clean side" and a colour side on the electrode and porcelian especially in 4 strokes if you are trying to read plugs by colouration.

Probably asked more questions than provided answers..........

Kiwi

 

Kiwi_Craig - the stock needles don't have any identifying letters or numbers stamped in them.


14mins - if you have a stumble from part throttle to wide open, I would try raising the needles to the top and try stepping back down quite a few on the mains. JMO
Raising the needles should get rid of a part throttle stumble.
I have taken the airbox completely off and watched the carbs work as the bike is idleing. Very interesting, the slides are constantly jumping up and down with the stroke of the engine (vacuum). At idle, they just barley move up and down. At quarter throttle, the slide are open quarter throttle, but there is a strobe like effect going on. You can see the slides are moving up and down so fast, kinda looks like they are in a strobe light. And at full throttle , the same thing, what I'm getting at is even if you put the biggest main jet in it, you might still have the stumble bog untill the needle is metering the correct fuel to air ratio. Try a set of the k&n needles or dyno jet needles if the stockers dont get it. Good luck.
turbo bobby

 

Played at the strip tonight. I have a crap load of jets coming tommorow from sudco. It runs fine full throttle from bottom to top. But when just crusing around it wants to stutter occasanally. I am guessing that it is in the 3500 to 4000 rpm range.

Sudco said that 192.5 and 197.5 jets were discontinued, anyone willing to part with some??????????

It is probably not a big deal, i just want it perfect. She is a runner. I have a 14thooth front and 40 rear and can launch her in 2nd. tonight i was still on the tank in 3rd to keep the nose down. She was hooking good!!!! I hate to have to back out of the throtle in 2nd when the nose comes up. Around here if you let off , you have LOST that race!!!! Tommorow i am going to install a 195 and a 200 with 25 pilots. I would like to get my hands on a 197.5. With the port and polish i figured that they were trying to get the head to flow even on both sides????