4-1 jetting...

Hey guys, im buying a kerker 4 into 1 for my 81' KZ1000LTD. was wondering how it might run with stock 122.5 main jets and the stock airbox as well.

Thanks guys,
KT

A 4 to 1 will lean out your mix. Does it have the baffle? Id be safe to say 2 main jet sizes, but ride the bike, see where it gets lean and work from there. you may play with clip positions to start and thats free to tinker with before buying jets.

it has a baffle and everything. Muffler is clamped on tight. It came with my dad's 81' KZ1000. the guy didnt like it cus he had to pull his center stand. My bike is running lean already i think. Never even the slightest stench of unburnt fuel and i adjust the pilot circuits to run a wee bit lean. with the stock exhaust, my bike was such a beast last year. I could drop down a gear and pass anything:D

in my opinion!! which everyone has one.. you'll be very pleased with the stock airbox ,same jetting..
my belief your air/fuel ratio will be staying the same even when adding a 4/1 pipe.. your just letting the exhaust breathe a little better.. if my memory seves me right.. the stock air boxes have velocity stacks built in side...
i just put a v/h 4into one on my 76ltd with stock air box and i'll assume stock jetting.. as i've not had the carburetors off to verify.. but there has been no bluing of the head pipes as you normally see on most pipes!! stock air box isn't very sexy or racey looking... but actually functios flawlessly... keep us updated how it runs..

I just put a vance and hines 4 into 1 megaphone on my 81 csr1000, my bike has the cv34 mikuni vacuum carbs. I thought my bike was running a little lean as well,(with the stock exhaust) I went one up on the pilot to 40 and started off two up on the main to 130. Well it was too rich, I went down to 127.5 on the mains and guess what, still too rich. with the 130's once I got into the throttle about 4500 rpm's or somewhere between 1/2 to 3/4 throttle she started breaking up. I put the 127.5's on and same thing just not as severe. I could actually bring the rpm's up through the breaking up. Do you think I could have fouled out new plugs with putting about 25 miles on the bike with the way too rich 130's? should I get new plugs then see what happens with the 127.5's? I have not touched the fuel/air screw. I figured I could get it close with jetting and then fine tune with the fuel/air screw. I don't know what the fuel air screws are set at. I think the guy who I bought the bike from richended out the fuel air screws when he put pods on it. (i know I have no cracks, or other issues with it being air tight) My next step was going to be bringing all the fuel air screws in and backing them off to 1 and 1/4 turns to the stock setting and seeing what happens. Then if still to rich adjusting them in untill hopefully she's running right. If I bring them close to all the way in then I might be going bakc to the stock jet setting. SOOOO, do you think I can get the bike from being rich enough to break up and make it through the rev range to running correctly with only a fuel/air screw adjustment? I understand that the fuel air screw will change how it runs throghout the throttle position, but I didn't think it would be that much of difference. I'm looking forward to the input. summers are short here and any downtime is wayyyy too long.