Open pipes and shimming carb
I cut up an old banged up set of original pipes a few months ago so I could put some 20" slip on pipes on the end. They sound fine and the bike ran fine during the time.
Last weekend I was given a pair of slash cut open pipes, again long pipes at around 20". I put them on, they took me by surprise. Loud and with a nice deep tone. I figured the longer and more bell shaped the pipes, the deeper the tone. Obviously at high rpm they sound a little more ****ty as I appreciate it's a small twin cylinder.
I ran them for a few days, but I don't think the old 450 twin is so happy with them. I have a feeling she is now running too lean, and checking the plugs yesterday they are pretty white.
If I was to keep these long slash cut open pipes, can I just shim the needles with washers to help richen up the mix? Do I need to also replace the jets too? Was hoping I could get away with just shimming the needle as they are easier to get at from the top.
Can anyone advise what size washers I need so they will fit over the needle and are the correct thickness?
1986 Rebel 450, a little bit bobbed here and there!