I bought a 1993 fj1200 abs from a man in Texas with 23k miles on it. It already has a suppertrapp 4-1 exhaust and when he sold it to me he gave me 2-1 foam pod filters. I need to know what size jets I should run and how much I need to shim up the needle jet for these mods. I'm a novice when it comes to carbs.
Use the search function
Don't you hate it when asshats at most sites respond with that?! (Also, to be honest, the search function here does leave a bit to be desired...)
Seriously now - welcome to the site!
I went through the files section - and I don't think we have a single comprehensive/concise post for this - lots of good info, but it is still a bit of a hunt.
Here's a hodge podge of info for you - only thing I really didn't get a good post for was shimming the needle. I'm sure Robert or Randy from RPM (banner up above) can help you out - they know these engines well. Also, where are you? Elevation will make a difference in the recommendations too. And make sure you confirm there is NOT a jet kit in your carbs before you follow this jetting advice. Different jet kits have different style needles that will make a BIG impact on the main jet size! This assumes the stock needles!
Jetting info that seemed closest to your setup:
http://www.fjowners.com/index.php?topic=1974.msg19698#msg19698 (http://www.fjowners.com/index.php?topic=1974.msg19698#msg19698)
New setup
Supertrap full stainless 4-1 pipe
UniPod filters
Main jets 117.5
Pilots 42.5
Needle 5Fz272 (stock)
Air 155 (stock)
Needle clip pos. 3 (middle)
Air screw 2.5 turns out.
Float height 21mm (lowered 1mm)
Blip test was hanging slightly, so I turned air screw out to 2.5 turns.(started at 2) Comes right back to idle. Re-Synced carbs.
After 1st test run :
Ran great. Low end and middle throttle response muchly improved. Driveabilty(is that a word?) is excellent. No hesitation from low rpm right through to redline. Pulled hard and steady. Maybe a little flat at top? (bigger mains? 120) is ok for now. Will ride a bit and tweak from here if need be. Check plugs after a ride or two. I think it is real close right now. Will have to check mileage.
Initial setting for idle mixture screws:
http://www.fjowners.com/index.php?topic=18722.msg189454#msg189454 (http://www.fjowners.com/index.php?topic=18722.msg189454#msg189454)
Fingernail setting for idle mixture
Adjusting the idle mixture:
http://www.fjowners.com/index.php?topic=19852.msg203332#msg203332 (http://www.fjowners.com/index.php?topic=19852.msg203332#msg203332)
Blip test
I live in south Arkansas so my sea level is 312ft. The whole bike is stock except a Corbin seat and the supertrap exhaust. The guy before really didn't take good care of the bike and I get pops and bangs on deceleration from it not being tuned after install. From what I have been looking at I might try a main jet 117.5 a pilot of 40 and shiming the stock needle .05mm.
^^^ That sounds perfect....