katana 750/600 engine swap question

[90katanarider]

I just swapped my blown 90 katana 750 engine for a good 91 katana 600 engine. I am using the old 750 carbs. Anybody ever done this? What size jets did you go with? I need a good starting point before I get a Colortune to get it as right as possible. Thanks

ride it and see what kind of responce you get
then take a plug reading
you may be ok

[90katanarider]

I already ran it up the street twice (first time the bike moved on it's own in 2 years). Runs strong but I have to feather the throttle or it bogs down. It starts real easy with minimum choke....not a suzuki characteristic. Between that and the larger than stock carbs I am thinking it is too rich. Once I put the air box back on with a K&N it will run richer yet. I feel sure I need to rejet it leaner before I do a plug read. I am hoping someone has been down this road before me to cut down on the trial and error game. thanks. wayne

whats the size difference between the 600 and 750 carbs
if they are the same size just change over the slow and main jets

if not start by jumping down two sizes and start from there

[90katanarider]

I'm not savy enough to know the specifics on the size difference (I've had a lot of technical help with this project) but I do know the new 750 intake stacks are of a larger diameter than the ports on the 600 engine. Dropping 2 sizes probably is a good start. Someone else made that same suggestion to me once. Guess I'll try it. Thanks a lot.