XJ650 to 750 done now the fun begins...

So now that the motor swap has been done, i need ideas on tuning the carbs and such, also...what does YICS do again? I used the stock 650 carbs and intake with the 750 motor, along with a mongrel 4:1 pipe wich will be ebayed shortly. I have the bike running well off idle, but at idle it spits and farts and generally feels lean. So what jets are the 750 carbs using? Also what does the YICs affect at idle? Just a bit stoked about the whole deal, cruzerjd

 

The YICS is supposed to blend and equal pressures coming from the carbs. You cant synch the carbs great without blocking the ports off first with a YICS tool.

120 and 40 are stock for the 750 IIRC. I think the 650 is 110 for the main (?). I am sure I wil be corrected if I am wrong, these people are smurt!

 

Cool, took the bike out today for a quick spin. All i can say is Holy Midrange! Where my 650 motor was struggling at the bottom end and was peaky in the midrange and top end, this motor pulls strong from 30- who knows what in 5th. No more downshifts to accelerate, just grab some throttle and go. I put the stock 650 exhaust back on and tuned the carbs as well as i can without the YICS tool. Bike idles great, runs well and is a pleasure to ride. Will be cleaning the YICS passage at work tomorrow and picking up the extra stator rotor. Always remember to tighten down al yur fasteners. I had a slight oil leak at the alternator cover and between the head and cylinder where the P.O. didn't tighten down the bolts well enough. Now i need to get a left side cover as mine flew off down the road and was pancaked this afternoon....off to eBay! cruzerjd

 

Right on Cruzer! Glad to hear you are making great progress. If your cover went flying, I'd be going over the whole bike with a torque wrench to make sure the other bits and pieces of your bike stay put!

 

The cover that went flying was the silver side cover over the electronics. Rode to work yesterday, bike ran flawless, but at one hill, it kind of bogged then packfired a bit and ran stronger than ever, must have had a bit of crap in one of the carbs. Looking to get a 750 cdi box, as the 750 motor responds to the better power curve of that one. cruzerjd

 

How did you go with the gearing is there a difference between the 750 and the 650 final drive?.What sort of revs are you running at 60mph cruise?
650~750~900!How about some pics?