I'm trying to rejet my carbs. I have a couple questions.

[niggalai]

i just recently purchased a set of velocity stacks for my mac 4-1 and aftermarket muffler to breathe through. the last time she was running it was difficult to get going any faster than about 65mph. my mac had the original muffler and pod filters then. at that point i had gone from size 80 to 100 on my main jets, and lifted the needle a notch. its also worth mentioning that i live at 8000'. i was thinking of upping it to 120 and going a couple sizes up on my pilots. do you guys think that this will get my bike to perform better? what tips/tricks can you tell me about tuning carbs? i know i have to sync them and havent gotten a chance to do it right yet, just by eyeballing haha. im also ready for plug chops and whatever else.

[hampshirehog]

What bike are you on about?

[niggalai]

1977 gs550

[hampshirehog]

120s are way to big. I would have thought at your altitude you're fairly close - time for plug chops.

Have you done the valves, igntion etc first though?

[niggalai]

havent touched valves yet, im planning a full rebuild over the winter. i'm also installing an electronic ignition system.