Got my SR4 on track for the first time today. Had the head redone by Carpenter, replaced crank bearings, etc.
More power was evident (unknown hours on engine when I got it) but after about 15 mins of running hard, I started getting some clutch slip.
Was able to verify once off-track doing a full throttle accel in 2nd gear from around 4k RPM.
Changing a Hayabusa clutch looks easy based on my on-line research, but is this a job that can be done with the engine still in the car? I put the car in the garage and forgot to take a look before quitting for the day.
I assume Suzuki OEM clutch pack is fine, right?
Thanks,
John
Engine has to come out, there is a chassis bar that will prevent the cover from coming off.
oem clutch kit
heavy duty springs
Ugh. Thanks GraemeD. Guess I won't be getting it done in time for track day on Wednesday.
I'll take pics along the way in case they're useful for others in the future.
Any reason not to install this, too?
https://store.schnitzracing.com/carpenter-clutch-modification-lock-ring-suzuki-hayabusa-99-07/
The at-idle occasional clunking really annoys me.
If you are very careful you could hold the engine on a crane and just turn it to remove the cover. Would mean you could just remove a few items like the chain etc.
OEM clutch pack is the way forward, Gen 1 or 2 will fit your engine.
The H/D springs fitted to the Gen 1 engine as standard are EBC H/D and will go weak over time. I am surprised the builder didn't replace/upgrade. Personally I would recommend upgrading to Gen 2 clutch pillars and bolts (part numbers 21481-24F32 & 21482-24F30) then use the Gen 2 HD clutch springs that Radical and RLM stock, worth trying somewhere like spring mountain to see if they have them in the USA. Retail is something like £15 gpb for a set but shipping would be more!
thanks Dan. I have the right side of the car up on stands now, in order to drain the oil from the clutch pack housing. I am planning to loosen the housing then see how much wiggle room I need, then will attach a hoist as you suggest.
hindsight is 20/20 of course, but if I were the chassis designer I would have structured those frame pieces a bit differently. Annoying that bikes can change their clutch in 15 mins and we can’t.
Yeah, annoying and not a problem in the SR3!
I would imagine that you would only need to replace the springs, as long as you didnt drive with clutch slip for a long time, but once you are in there worth doing the plates.
If you have had bad clutch slip for some time make sure you check for any debris that could be in the oil system and cause other problems.
Well, I’m happy to report that it’s possible to wiggle the clutch housing out between the engine and frame, at least in my SR4.
And there is still a bunch of oil that comes out when the car is tilted to the left, as my garage floor can attest.
Waiting for the clutch kit and stiffer springs to arrive.
Great job John!
Wow, I would have never guessed that cover would come off the way it did.
There isn't much clearance (maybe 1/8"?) and you have to maneuver the cover around a good bit. I'll try to get a video tonight in case it helps others.
Ok, here's a quick video on removing the clutch cover.
I found that the steel (driven) plates were in the wrong order. The thick plates need to be in the middle. They were at both ends of the stack.
Also, I found that the outside fiber (drive) plate was put into the same slots as the rest of the plates instead of in the "special" slot that is reserved for the outside plate.
All measurements are within spec and everything looks basically new, no glazing at all.
I'm hoping the heavier springs will help.
@johnsopa that's great news! Maybe it is the PR6 that you cannot get the cover off with the engine in, I am sure there is one model that you cannot!
The thick steel clutch plates not being in the correct place and the last plate not being offset shouldn't cause your problems, although it is good practice.
Hopefully the springs will sort it, which ones have you gone for?
Great video John!
