more carb issues

[1980gs1100l]

i pulled my carbs apart this weekend the reason for was my bike bein hard to start when its cooler and if you held the throttle steady at 2-3k it would pop thru the exhaust i pulled the carbs cleaned them as throughly as possible without seperating them found the po had apparently tried to jet the carbs for the kerker exhaust went from a 107.5-125 but he accidently put 3 125 and a 112.5 any way i installed 125 all the way on mains left the stock pilots 45 and installed back on the bike. my idle sounded good hold at 2-3k now pops back thru exhaust and carbs and if you go from a warm idle to full throttle in neutral it bogs down before it picks its head up judging by this am i lean rich or what what direction do i need to go thanks

[Don-lo]

You probably need to richen the midrange, which is accomplished by raising the needles. The needles are in the slides that come out of the top of the motor. If they are aftermarket (dynojet), there will be notches on the top, and moving the clip raises or lowers the needle. With stock needles, you need to shim up the needle with one or 2 precision washers (radio shack). Try 2 washers the first time, it may be all you need. If you start fouling plugs, go back to 1 washer. 125 mains should be close.

[twinapache]

How do the plugs look? Any black/grey smoke? If you're getting some popping/sneezing back thru the carbs, that is an indication that cylinder is lean

[Steve]

With stock needles, you need to shim up the needle with one or 2 precision washers (radio shack). Try 2 washers the first time, it may be all you need. If you start fouling plugs, go back to 1 washer.

Methinks you have the washers on the wrong side of the clip.

In stock configuration, there is a thin metal washer under the clip and a thick nylon spacer above it. Below that thin metal washer is a spring that is pushing the whole assembly UP. If you add washers under the clip, all you will do is increase preload on the spring, the needle will not change position. To "shim the needle", you need to find a stack of washers that total the same thickness as the thick nylon spacer, then REMOVE some of them to allow the needle to be raised a bit higher. With the washers mentioned, four of them usually do the job. Start by removing two, then fine-tuning from there. Fewer washers richen the mixture by allowing the needle to rise higher.

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[Don-lo]

Steve, methinks you are right.

I was locked in on VMs, lol