I have had an issue with a clunk off start for quite awhile now. sounds like someone is tapping swingarm near front sprocket with small hammer when clutch engages in first sometimes in second. this does not always happen. maybe once in 10 times off dead stop. i don't race and am very perticular. i have been working on this for 12 months. unenjoyable riding. i had some advice from a racer who owns his own shop.
first.... the chain should be tight by my standards, on a wheel stand you have to pull hard up a scant 1/2 inch and down a 1/2 inch, check in on the ground, it is the same. no loose chainy ****, like older bikes. no finger up and down an inch.
second, there is a cam with dog ears in the clutchat the drive/counter shaft to prevent smooth and positive clutch release. Suzuki is insane, ask the pros on busas
this cam is between the drive basket and the countershaft, it has three dog earsattached to the shaft. the clutch drive has a collar with notches for the dog ears but the thing is that the collars notches are 10 degrees or so too wide and they are rounded on the bottom so the dog ears that drive the sprocket have to clime the rounded bottom and hit the side of the collar before the sprocket moves. like a bilt in delay on clutch engagement. this makes noise when you let out the clutch just right. add a loose chain and bingo. the clutch mod everyone talks aboutis just welding the the dod ears to the collar, then you need a spacer on the springs/ spring studs to compensate for the the fact the dog eared piece doesn't climb any more and move the springs tighter that little bit.
i still don't know why anyone can't explain this on this forum in simple terms. i have had a year figuring this out. the hayabusa is the only bike with this kind of crap going on in the clutch. some engineer thought they needed a little delay in engaging the clutch. the other deal with this is that for racers, when they drop the clutch, it slips a bit as the dog ears clime to the stop and then set. ( a .01 secind or so) and then the clutch hits hard because the lever has already been released and now the plates slip a bit more because they are being dropped and locked so fast by hard mechanical action of the dog ears hitting the collar ( the clutch cam mechanism). when the dog ears hit ( the cam) it is instant, the clutch has to slip to make up the difference between the motor and the rear wheel.
this is why the busa seems so weird off the line, and why shifting seems so unique when compared to older or other bikes. you never feel like the clutch is really tied to the tranny as you have felt with other bikes. little lag always. when you let the clutch out fast you get a little engagement and then a positive. when you let it out slow you get a liitle hesitaion or a clunk, at times.
i just inspected this assembly, and figured it was causing most of my confusion after having a click clunk noise in my chain on take off.
a brilliant design for the engineers who wanted to intentionally make the clutch slip for a hundreth of a second or so when you dropped the clutch. a nightmare for those who are expecting a clean clutch like they had on any other bike. i am having my cam assy welded by my machine shop for 20 dollars and buying a new gasket for the the cover. then i will put in 2mm thickwashers in the spring studs to compensate for the ammount the dog ears clime on the u shaped corners of the notches when the clutch actually engages. all the racers seem happy paying 200$ for this modification just do the clutch works like any other clutch on a normal motorcycle. as i said i don't race i am just really tired of that screwy clutch.
for any ppl that don't get this can see this site for part fiche for your bike, just be sure to bookmark it..
http://www.ronayers.com/fiche/getyear.cfm?groupid=5200&man=su
or this site for a free service manual in pdf format WELL i can't find the site anymore....
i saved it, if you email me i will send you the complete 70$ service manual for free in pdf only 8 mb.. no problem. is easier to use than my paper one
