Pilot jet question

Alrighty then..The bike is running good except right when I take off.. A slight stumble.. I posted earlier that my bike was popping out of #1.. I am now convinced that that is a valve shim.. I'm running 117 mains, 17.5 pilots and am on the 4th clip on the jet needle.. Yesterday I put the stock 15 pilots back in and the bike had a huge stumble off the line.. Now I have the 17.5's in and it is better but still a slight stumble.. Should I go up to 20's? According to these rules.. THESE RULES I should go up 2 sizes on the pilots.. I had 97.5 stock mains.. I've gone up 8 mains.. The bike screams, just the slight stumble off of the line.. What do you guy's think? Here is a pick of the bike.. Not in the best shape as it sat out 2 Winters and stored for 8 years. I've tried to get some of the rust off and clean it up a bit.. Still work in progress..

Well, since nobody answered my post I'll answer it myself.. I put the 20 pilots in and that made all the difference.. No popping out of #1 carb, no flat spot.. All is good thanks for the replies guy's..

Hey Vach,
I'm having a similar problem with my 1300. In addition to a stumble off of idle. I'm experiencing a surging while riding with the throttle just barely open. On a 1300 that's most of the time. I've clean every thing so I guess I'll go for some bigger pilot jets as soon as I can find a magnifying glass with which to read the jets I have.

Glad you found your solution.

KZCSI

The pilots on Bill's bike are likely BS30/96 style where the ones on the Vach's bike are likely VM22/210 style. They are very similar but don't swap. The BS30/96 pilots are just ever so slightly larger and are used on almost all vintage Mikuni constant velocity style carbs. The VM22/210 pilots are slightly smaller and are used on the VM24 and VM29 Mikuni carbs. If you try and remove either, the secret is to use the CORRECT flat blade screwdriver. Have your new pilots on hand and fit your screwdriver blade into one of the slots. It should fit snug... problem is, it is a small, shallow slot and strips pretty easily; especially on the BS series carbs for some reason. I took one of the jets to a Sears and bought the correct sized slotted screwdriver... it is about 8" long and fairly small/light. The next trick is that you usually will have to grind down the edges just a tad so it will fit in the pilot well. If you are not comfortable about removing stripped pilot jets, first heat the well (remove all rubber stuff first) with a propane torch... just a minute or two and squirt some PB Blaster down the well. The heat will cause it to flow on the thread. Then take a set of vise grips and lock the handle of the small screwdriver. You use the vise grips for leverage. Press down HARD on the screwdriver when you get it lined up in the slot and turn the vise grips with your other hand gently... you will feel the little pilot jet break loose with a snick. At that point, do the others the same way as this pilot jet will come right out now. If you do strip one, you can generally use and EZ Out to extract it. A left hand drill bit will also work. The square type extractors generally can't fit down far enough in the well. Just be sure to use the correct sized drill bit prior to using the EZ Out as the brass is soft and you will end up having to try and drill the jet out and retap the hole which can also be done if you are careful. The BS30/96 is 5mm with .8 pitch if that needs to be done as it sometimes is. Can't recall the VM22/210 but believe it may be 4mm with .7 pitch.