Stupid question #1

No eBay APP ID and/or Cert ID defined in Kunena configurationHey guys, I am new to having an older bike and have a quick question regarding replacing my exhaust and rejetting. My po hacked the exhaust to shreds and now it's running straight pipes. I'm running extremely rich enough so that I can't hardly warm up the bike without it bogging down after I close the choke and take off. It will run like crap for a couple minutes and even stall. I talked to a mechanic and he says the straight pipes may be the issue. I have a new exhaust picked out but I'm not going to have the cash to rejetting for a little while. Will I be ok switching to 4 to 1 and not rejetting for a couple months? Or is it going to cause issues? Here is the exhaust I'm probably going to pick up

Got a book??

No I dont. I'm looking into getting one

Do your pocket a favor and get a kawasaki service manual for the year of your ride everyone here will tell you the same. :side: Keep a cool tool

If the bike is running straight pipes right now, then that ZR750 system probably isn't going to hurt anything.

What motorcycle is it & is the stock airbox installed? There may be a pdf available.

Still has stock airbox (thank goodness) and it's a 77 kz650. I know Gringo has put this style exhaust on one of his so that's where I got the idea. I have a local machine shop that can fabricate a bracket no problem

If it gets worse when you close the choke, then it's likely too lean. Needing to run either a lot of choke, or long warm up times before being able to take the choke off means the low end is lean. You don't say what part of the throttle it runs like crap, but thinking it's lean somewhere.

DGA is probably correct. The "choke" on a KZ is actually an enrichener for the uptake of more fuel. The straight pipes are probably causing a lean condition. Not sure about the 77, but most KZs were jetted lean from the factory to meet EPA regs --- straight pipes would exacerbate the lean-ness. Also, if the carburetors haven't been cleaned, the pilot circuits cold be clogged, often times indicated by having to use the choke. no pilot circuit, no idle, bikes dies when choke is turned off.

Ok I just got some info from the po. He completely forgot to tell me that it has been stroked and bored and also has hot cams. This may be part of my issue. Good news is that it has adjustable jets as well. so I can take it to a shop and they can just synch the carbs and tune it for me. I guess the bike has been sitting for about 4 months so it might just be a minor issue. Either way I got that exhaust ordered and that will go on BEFORE I have the shop tune the carbs. I didnt realize how much work this bike had put into it

Stroked, adjustable jets, pics? :huh:
Steve

Yeah its had a quite a bit of work done. I dont have any pictures of the work being done unfortunately, but you can tell its been done this thing screams too. I walked all over a cbr on my way home with it. Wont be doing that too often though. Not a fan of stupid fast speeds.

I think you were sold a bill of goods. Yeah, the jets are adjustable by changing them and the pipes are costing you some ponies. As for the stroked part :whistle: Got a manual? Pics of the plugs?
Steve