Driveline / Transmission play

[Audiomaker]

Hi All,

I've just recently purchased a 2002 turbo Hayabusa.

One thing that has really bothered me about it is how jerky it is in around town riding.

This bike is high mileage so I'm expecting more than average maintenance. It has 40k on it.

Anyway, I know there are likely plenty of worn things in this driveline. I've already had the cush drive replaced with a better (but still used set) when changing the rear tire. It's good.

I had the bike up on stands today and had the bike in first gear and started rolling the rear wheel back and forth to confirm what I already suspected.... the front sprocket is rotating quite a bit before meeting the resistance of the engine.

So I haven't gotten too far into this (Like I havent tried it in all the gears yet), but I'm quite sure this is the source of the "clunk" I get between acceleration and deceleration.

Now I know a bit of this is normal... all bikes do it, but I think this one is excessive and needs something. It is at a point where it affects my confidence in turns because any throttle motion at all opposite the current position produces a solid jerk at the rear wheel. There is no gentle roll off... or roll back on.

What would that something likely be?

What other tests can I do to provide the board with the information needed to diagnose this problem.

I have a pretty good shop and am 4 hours from the nearest mechanic that I'd trust.

Thoughts?

Thanks
Sean

 

[red1100cc]

with the HP the busa puts out and the torque of the engine even at low revs, and you with a turbo, it is going to be a little "jerky" putting around town.
i recently went up 3 teeth in the rear sprocket and have noticed i have to really pay attention, in order to be smooth in my shifts.

 

[Audiomaker]

with the HP the busa puts out and the torque of the engine even at low revs, and you with a turbo, it is going to be a little "jerky" putting around town.
i recently went up 3 teeth in the rear sprocket and have noticed i have to really pay attention, in order to be smooth in my shifts.

I can appreciate that, but I think this is beyond normal play.

Not knowing these bikes, I'm wondering what wears out that could induce extra play into the front sprocket rotation. My sprockets are new by the way.

Sean

 

[red1100cc]

hum, i donno then.
post up a video and give us a look.

 

[aussiebusaboy]

Thought i might resurect this thread as i have had this issue for a few months now.
I love how the standard response if to check the cush in the rear wheel.

The problem here is one that has the chain moving about an extra half inch on the front sprockets play even when the rear wheel is removed.
So to shoot down all the common responses, its not to do with anything on the bike except the play between the clutch and drive train up to the front sprocket.

i am toying with a total replacment slipper clutch to try and fix the issue but i certainly seems like the front sprocket has more play and i dont know how the BTL plays into this.
Since this happened on my Busa ( after 20k miles) i have noticed the engagment clunk is louder, the slop between on and off in tight 1st and 2nd gear corners is dreadfull and the clutch actually shudders if i let it out gradually on idle in 1st gear.

Before 20k miles the play on the chain was minimal, the bike rode well, after 20k miles something changed, the clunk was louder, the play is greater and the bikes ride is certainly worse for it.

so 20 years riding exp, 20,000 previous miles to campare against the bikes current stance and i can tell you its something that needs fixing for sure.
My bike is stock, no major mods, no tinkering, no adjusting of cables, always serviced by same guy and nothing out of the ordinary to tell me why this would have happened but it has and its ****e.

i am seriously hoping someone with enough nouse can work thier way past the rear wheel cush suggestion and offer any fix for this issue.
And before you ask, i am not posting a video to show how much more slack is playing on the front sprocket, you will have to take my word for it.
I would love some info on how this back torque limiter might affect my clutch play and possibly cause this issue.

 

[Billyroe]

I am currently dealing with the exact issue you described and what i've found from research is that the Brocks clutch mod deletes the slipper clutch function and the play that is associated with it? someone correct me if im wrong im about to order the clutch mod in hope that it does something!

 

[The Gribbler]

I have this same problem.. I checked the cush drive and it was fine. My chain deflection is within spec. I replaced the back torque limiter/ clutch cam doo dad with the Brock's clutch mod. That seemed to have helped a little bit but did not address the majority of the issue. Entering turns in second gear is difficult because when I get back on to the throttle there is a jolt forward like there is slop in the drivetrain. I'm I called a shop that works specifically on Busa transmissions and the guy said "second gear is junk" on them. He didnt say why or how, and for all I know he was just trying to talk me in to giving him work. Who knows. What I do know is that there is a slight clickety clack coming from my intake duct around 2-2.5k rpm. I am thinking this is my cam chain not being taught. That got me to thinking that if my cam chain has slack in it, decelerating in gear then applying throttle ( no matter how gently) may produce a similar effect as transmission slack. HEAR ME OUT! This is purely based on this theory: I would be willing to bet that on DECEL, the cam timing Advances. On ACCEL, cam timing retards because of the slack in the camshaft chain. The dead spot between the two would allow the motor to lose power then jolt as it regains power. I feel like this will cause an effect that would feel like transmission/ drivetrain slack.


Who knows.....

 

[DesertSlasher]

I have this same problem.. I checked the cush drive and it was fine. My chain deflection is within spec. I replaced the back torque limiter/ clutch cam doo dad with the Brock's clutch mod. That seemed to have helped a little bit but did not address the majority of the issue. Entering turns in second gear is difficult because when I get back on to the throttle there is a jolt forward like there is slop in the drivetrain. I'm I called a shop that works specifically on Busa transmissions and the guy said "second gear is junk" on them. He didnt say why or how, and for all I know he was just trying to talk me in to giving him work. Who knows. What I do know is that there is a slight clickety clack coming from my intake duct around 2-2.5k rpm. I am thinking this is my cam chain not being taught. That got me to thinking that if my cam chain has slack in it, decelerating in gear then applying throttle ( no matter how gently) may produce a similar effect as transmission slack. HEAR ME OUT! This is purely based on this theory: I would be willing to bet that on DECEL, the cam timing Advances. On ACCEL, cam timing retards because of the slack in the camshaft chain. The dead spot between the two would allow the motor to lose power then jolt as it regains power. I feel like this will cause an effect that would feel like transmission/ drivetrain slack.


Who knows.....

That’s what I was thinking, I’m trying to research why there’s so much play in the front sprocket, everything else is good but even when the chain is off you can grab that thing in it has a lot of play. I did the clutch mod but that’s not for this kind of play, the clutch motors just so it doesn’t rattle around on the right hand side of the bike but the sprocket still has the play. I’m with you on the timing chain thing, although I never hear any noise from the intake that would make me suspect it’s loose at all. Maybe it’s just worn out