Possible.clutch slip?

[James417]

Clutch is acting wierd on my 99 gen 1. Ok so before i ramble I have had the bike for about 8 months now. It's got 15k miles and counting. Popped the clutch cover and checked the clutch and everything is in seemingly ok condition. Plenty of material on friction disks and plates and springs look good. Clutch does do the famous busa rattle with clutch lever let out while idling and feel like "knock" through bike when revved. Doesnt do it with clutch lever pressed. Shop said most older gen 1s do this said its because of something called a torque plate?
Anyways whats happening is on hotter days when engine is running hot in lots of slow stop go traffic, im noticing clutch gets weird. Starts to engage farther and farther out until like 8th of inch pull on the lever. Then seems to "clack" into gear harder from neutral when hot like this. Also noticing when I am trying to accelerate hard it feels like a sudden loss of power for a bit up to near 6 to 7k (I think max torque power band) than comes on pulling like freight train higher rpms. Some times it pulls really hard all the way through the power band like usual. It wasnt doing this while back near when I first got it and clutch noise is now bit more pronounced. Could this be clutch and that clutch rattle be sign of clutch going bad? Its all stock no pc or ecu flash slip on shorty pipes with tiny baffles so not really a performance exhaust. Lol Brand new rear tire 2ct so unlikely its spinning on hot day. Any ideas?

 

[WuzzaCBXRider]

Clutch is acting wierd on my 99 gen 1. Ok so before i ramble I have had the bike for about 8 months now. It's got 15k miles and counting. Popped the clutch cover and checked the clutch and everything is in seemingly ok condition. Plenty of material on friction disks and plates and springs look good. Clutch does do the famous busa rattle with clutch lever let out while idling and feel like "knock" through bike when revved. Doesnt do it with clutch lever pressed. Shop said most older gen 1s do this said its because of something called a torque plate?
Anyways whats happening is on hotter days when engine is running hot in lots of slow stop go traffic, im noticing clutch gets weird. Starts to engage farther and farther out until like 8th of inch pull on the lever. Then seems to "clack" into gear harder from neutral when hot like this. Also noticing when I am trying to accelerate hard it feels like a sudden loss of power for a bit up to near 6 to 7k (I think max torque power band) than comes on pulling like freight train higher rpms. Some times it pulls really hard all the way through the power band like usual. It wasnt doing this while back near when I first got it and clutch noise is now bit more pronounced. Could this be clutch and that clutch rattle be sign of clutch going bad? Its all stock no pc or ecu flash slip on shorty pipes with tiny baffles so not really a performance exhaust. Lol Brand new rear tire 2ct so unlikely its spinning on hot day. Any ideas?

The springs “look good”? Springs look the way they look whether they’re good or not. The knock may be a loose bolt inside.

 

[Bumblebee]

How's the oil looking? These things are sensitive to the type of oil used as well.

I've seen gunk build up under the front sprocket cover which made the push rod for the clutch a bit sticky...

 

[James417]

The springs looked good as in not loose when checking the torque on bolts when putting it back together. So yeah you are correct there could still be an issue with a loose bolt/spring. And oil condition is pretty good. Just changed about 2 months ago and topped off looking good I use mobil 4t racing oil about 300 miles sense last change. Maybe it's slipping badly when hot due to the oil type im using? Is there a better oil than the mobil 4t?

 

[Bumblebee]

The springs looked good as in not loose when checking the torque on bolts when putting it back together. So yeah you are correct there could still be an issue with a loose bolt/spring. And oil condition is pretty good. Just changed about 2 months ago and topped off looking good I use mobil 4t racing oil about 300 miles sense last change. Maybe it's slipping badly when hot due to the oil type im using? Is there a better oil than the mobil 4t?

I've never heard of any issues with Mobil oil..

I and a few others use Amsol-seems to work good.

 

[Dopey]

The springs looked good as in not loose when checking the torque on bolts when putting it back together. So yeah you are correct there could still be an issue with a loose bolt/spring. And oil condition is pretty good. Just changed about 2 months ago and topped off looking good I use mobil 4t racing oil about 300 miles sense last change. Maybe it's slipping badly when hot due to the oil type im using? Is there a better oil than the mobil 4t?

I run nothing but the 4t in my second gen and never had any issues . Actually after the first time I put it in the bike I decided I wouldn't use anything else.

 

[Dustin02]

Same here. Mobil 4T...

 

[James417]

I run nothing but the 4t in my second gen and never had any issues . Actually after the first time I put it in the bike I decided I wouldn't use anything else.

Yeah I love the mobil 4t i ran it in a 90s gsxr and it did amazing with it. Starting to think I'm having issues with clutch or maybe engine is truly hesitating for some reason... Oh well still really need some sort of fuel management or tune. Btw guy tonight on a 07 08ish r6 with extended swingarm trying to say he had pistons rods and tune making 200 wheel hp lmao. That was a trip. Dude goes that busa weighs about 1000 pounds lmao!!! I was like I know they are known as heavy bikes but no about 550lbs. He was like whatttt?! Cool guy but that was

 

[rubbersidedown]

Yeah I love the mobil 4t i ran it in a 90s gsxr and it did amazing with it. Starting to think I'm having issues with clutch or maybe engine is truly hesitating for some reason... Oh well still really need some sort of fuel management or tune. Btw guy tonight on a 07 08ish r6 with extended swingarm trying to say he had pistons rods and tune making 200 wheel hp lmao. That was a trip. Dude goes that busa weighs about 1000 pounds lmao!!! I was like I know they are known as heavy bikes but no about 550lbs. He was like whatttt?! Cool guy but that was

He's a cool guy ? OK...cool guy has half of 200 HP.
Rubb.

 

[rubbersidedown]

@James417 man you gotta talk slower bro,1 thing at a time. Yer all over the place. We don't lose when it comes to the diagnosis of problems.Might take time,but I don't recall us losing.
Give us better exact details one at a time,leave out the guesses.
You think you have a clutch issue,OK. Lets start there.Is it slipping?
Rubb.

 

[James417]

Yeah your right I went way off topic there sometimes I get way too ahead of myself lol. It feels like a clutch slip when it happens but not as harsh as my katana I had that was slipping felt like pulling in on clutch lever. More like loss of acceleration engine still revving like clutch slightly slipping possibly. But the old test put it in higher gear load engine and try to accelerate and no clutch slip.

 

[Kiwi Rider]

One thing no one has mentioned is the hydraulics actuation of the clutch....

The first thing to check is the clutch hydraulics.
First off, bleed the clutch and give it a dose of fresh fluid. Be sure there is no air remaining in the system.
Then test ride it, now is it still having the same issue? Or is it behaving normally?
If it’s normal, overhaul the clutch master cylinder with a piston and seal kit and slave cyl kit also.
If it still had the same issue after the initial test ride, look further into the clutch itself, check spring length, friction plate thickness, stack height, notches on the basket?
It sounds like it’s an actuation issue from the hydraulics, more likely.

 

[James417]

One thing no one has mentioned is the hydraulics actuation of the clutch....

The first thing to check is the clutch hydraulics.
First off, bleed the clutch and give it a dose of fresh fluid. Be sure there is no air remaining in the system.
Then test ride it, now is it still having the same issue? Or is it behaving normally?
If it’s normal, overhaul the clutch master cylinder with a piston and seal kit and slave cyl kit also.
If it still had the same issue after the initial test ride, look further into the clutch itself, check spring length, friction plate thickness, stack height, notches on the basket?
It sounds like it’s an actuation issue from the hydraulics, more likely.

Ok so update: Been a while had to get fork seals and brakes done but, thank you very much for the suggestion to bleed and change clutch fluid. Got some fresh dot 4 in it and clutch feels amazing now! Big difference now starts engaging about the half way point and grabs with a nice friction zone as well as shifts much smoother. Got alot more riding in with it and even though still have some power loss in high rpms inevitably with my open "exhaust" and no tune lol The clutch feels better then ever now. Feels like torque come on harder in lower rpms now although probably placebo lol

 

[Kiwi Rider]

Ok so update: Been a while had to get fork seals and brakes done but, thank you very much for the suggestion to bleed and change clutch fluid. Got some fresh dot 4 in it and clutch feels amazing now! Big difference now starts engaging about the half way point and grabs with a nice friction zone as well as shifts much smoother. Got alot more riding in with it and even though still have some power loss in high rpms inevitably with my open "exhaust" and no tune lol The clutch feels better then ever now. Feels like torque come on harder in lower rpms now although probably placebo lol

So glad to be able to give suggestions and guidance . . . sounds like you have had a great time, happy to help!

 

[Mythos]

Starts to engage farther and farther out until like 8th of inch pull on the lever. Then seems to "clack" into gear harder from neutral when hot like this. Also noticing when I am trying to accelerate hard it feels like a sudden loss of power for a bit up to near 6 to 7k (I think max torque power band) than comes on pulling like freight train higher rpms.

Sounds like the clutch fluid was expanding from heat and increasing pressure to the lever and also the clutch slave. You would have less free play in the lever and the clutch would not grip as tightly. Water accumulates in the fluid over time. Water lowers the boiling point of brake fluid but that would cause air in the lines which would give you less pressure. It sounds like you had more pressure. I doubt a clutch hydraulic system gets as hot as a brake hydraulic system so maybe the fluid was just expanding from heat rather than going to a full boil.