Lockup clutch but still slipping, tips & tricks?

[Gixer1460]

You shouldn't need to raise spring load on a road bike, we've used softer springs when racing to induce a degree of slip on launch.

What weight have you got on the arms at present?

What state is the clutch basket and hub in? If they are a bit notchy then that may start the slip.

[bruteforce]

Hi Gixer1460, I have the standard bolt-2washers-nyloc nut on each arm, and run fresh standard spec (coil) clutchsprings. This should be OK. 

 

I DO have a little notching in the basket as it's a 30yr old motor. In the meantime I have gotten 2 spare baskets that I'm dreading to put on because I fear whining noises from non-matching main gears.

[Gixer1460]

3 hours ago, bruteforce said:

Hi Gixer1460, I have the standard bolt-2washers-nyloc nut on each arm, and run fresh standard spec (coil) clutchsprings. This should be OK. 

I DO have a little notching in the basket as it's a 30yr old motor. In the meantime I have gotten 2 spare baskets that I'm dreading to put on because I fear whining noises from non-matching main gears.

Sorry to mislead - I was thinking GSX baskets ie. aluminium - usually chewed to buggery! GSXR steel baskets usually mint. A ridged hub can be filed to smooth if really bad but it will usually return.

[wombat258]

11 hours ago, bruteforce said:

Hi Gixer1460, I have the standard bolt-2washers-nyloc nut on each arm, and run fresh standard spec (coil) clutchsprings. This should be OK. 

 

I DO have a little notching in the basket as it's a 30yr old motor. In the meantime I have gotten 2 spare baskets that I'm dreading to put on because I fear whining noises from non-matching main gears.

The standard coil springs do not give enough preload. You need a set of heavy duty springs (Barnett). That is what I run, with 1.5mm spacers to reduce installed height. Each arm has aluminium cap screw, aluminium nut, and a steel washer. 260 hp with no slip, and can still operate clutch at full rpm. Yes, drag racers use slip to get off the line, but they replace clutches frequently, and have to regularly dump the oil and filter because of the clutch dust.

[NipsuGoesRace]

Hi guys, I also need an advice with this same clutch issue. I have a boosted oil cooled Gsxr 1216 with mtc 2 stage lockup and on last dyno session clutch started to slip first at just under 1.4 bar 9000 rpm and after that I put more weight to the lockup arms. (Change was m6 16mm bolt to m6 30mm and 4 washers to 6 washers). Next dyno run and clutch was slipping again,  another try and warm clutch hold the run 1.45 bar 340whp at 10000 rpm. Now the clutch lever is so  heavy that I can`t press it down above 7000 rpm but difference between slipping line is just margin between these two setups. Is there any benefit put more weight to the lockup arms? Or should I try something else, like put more diaphragm springs to a raise clutch spring load, I have now two barnett heavy duty springs there and the clutch friction plates was relatively new. 

[Arttu]

Sounds like you have at least enough pressure on pack if you can't pull in the clutch at high rpm. So I wouldn't add weights or spring load before checking everything else:

-Is the air gap correct, can the levers press the pack all the time? (Not bottoming out on something)

-Are the steel plates straight and flat? And if they are glazed glass bead blasting can help a lot.

-Clutch hub and basket smooth and straight?

-Operating mechanism not limiting compression?

[Duckndive]

You have something wrong I ran just a nut and bolt on a single stage coil spring lock up draw Thru turbo 240bhp not problem 

[NipsuGoesRace]

Need to check these things. Thanks. If I need a new clutch plates, is there any benefits buy something aftermarket product like a Trac King or is a suzuki oem the safest choice. Both clutches price range is almost same.

[Duckndive]

2 hours ago, NipsuGoesRace said:

Need to check these things. Thanks. If I need a new clutch plates, is there any benefits buy something aftermarket product like a Trac King or is a suzuki oem the safest choice. Both clutches price range is almost same.

OEM every time....

[Gixer1460]

35 minutes ago, Duckndive said:

OEM every time....

x2 - streetbike through funnybike ALL use OEM! Don't know about roundy - roundy .... they never seem to stay vertical long enough to worry about clutch slippage LOL!

[MeanBean49]

On 9/16/2018 at 5:12 PM, Gixer1460 said:

x2 - streetbike through funnybike ALL use OEM! Don't know about roundy - roundy .... they never seem to stay vertical long enough to worry about clutch slippage LOL!

Roundy roundy types only use OEM too lol. More vertical stuff in one track session than a weekend drag racing ;-)

[CockneyRick]

I stay well away from Fully Synth. Semi for me oil boilers & Mineral for the Air cooleds  

[Gpz1100_Convert]

the basket inner hasn't got ridges in it from hard launches has it? Mine was kinda fucked due to this and it caused issues pulling the clutch out and engaging after the last time I ran it up the strip. I tried a needle file to smooth it but in the end bought a new basket.

 

Mark

[no class]

.....have you checked the clearance from the push rod to hydraulic clutch  piston ?  if  the rod  is too long it will bottom out   the piston   , the clutch pack will not fully engage.  as the fibers wear ....it will get worse .

[NipsuGoesRace]

• Now I finally got the clutch out. Fibers aren`t weared at all, they were between 2.52-2.57mm. Steel plates also looked good, straight and flat. Inner and outer baskets seems to be like they should be. Lock up air cap was 1.9mm so there was an error, it should be 2.5-3.1mm, but the extra arm weight may compensate this? My clutch push rod is 104mm long, so it is a little longer than it should be, 89-90 pushrod was 100 mm and 91-92 was 101.5mm. But it seems to be okay with a bandit sprocket cover that I use, it fits nicely to it`s place without bolts. Maybe I`ll chop the rod a few mm, just to be sure. The oil I used was mobil delvac mx 15w40 and there was too much oil (max 1L) in the engine when the clutch was slipping for the first time.  Winter is coming, so now  I have six months time to solve this.

[CockneyRick]

Before you chop your push rod, do as suggested & use a wood dowel with the length possibly needed.

If it don't work, then at least you know before chopping up the rod  

[nitro]

If you have a torquy engine with mild cams it creates power at low rpm when the Lock Up does not turn fast enough to "lock up". If you dont want build a boost compensated Lock Up (witch is easier to build imo), then it´s better to rise the base pressure.