VIFFR Posted April 1, 2020 Share Posted April 1, 2020 Hey guys, Im having an issue with my 99 vfr's clutch. When it's fully depressed i can feel it slightly pulling on the rear wheel like it's trying to drive me forward. It's easy to hold it in place, so it's not grabbing too hard. If i give the throttle a blip i can feel it release the tension on the drive train and it's fine for a while till i stop again What have i done to try to remedy this problem? *Fresh fluid and bleed *Rebuilt slave cylinder *Rebuilt master cylinder *Pulled clutch friction plates out and measured. All at 2.9mm (min thickness is 2.6mm) *Measured clutch spring static length and all came up fine. I haven't checked the steel plates for warping yet. I'll get a piece of aluminium from work tomorrow to act as a flat surface for the feeler gauges. I don't know if it's normal or not, but it took a bit of effort to separate the friction plates from the steel plates. Most of them were stuck together. They look a little burnt, but are very smooth. Ive tried up upload pic but it keeps falling... Details on the bike and clutch: 105,000kms Barnett heavy duty clutch friction plate Barnett heavy duty springs Have done about 40,000kms About 50 passes at the drags (11.4x best time) Has also done a lot of highway committing. Writing all this out, i realized ive changed the brake and clutch levers to some cheap adjustable ones and haven't put the stock ones back on yet. O_o Anyway, thanks for reading. Hopefully i can get some answers. Hopefully it's the clutch lever! Link to comment Share on other sites More sharing options...
VIFFR Posted April 1, 2020 Author Share Posted April 1, 2020 Oh hey the pic appeared! Link to comment Share on other sites More sharing options...
Member Contributer ducnut Posted April 1, 2020 Member Contributer Share Posted April 1, 2020 Some thoughts: You may visually compare the aftermarket levers to your OEM levers, just to make sure they’re identical in the important areas (pivot point > inward). Bleed the clutch system one more time. Did you pull out the clutch pushrod and give it a good cleaning? Are you positive your master cylinder seals are correctly installed and there’s no leakage past the piston? I’m wondering if the clutch plates are glazed enough to be sticking together or there’s warpage in them? Drag racing is so hard on clutch plates. Sounds like you’re on the right track with your own thoughts, though. Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted April 1, 2020 Member Contributer Share Posted April 1, 2020 First inspect the friction plates for glazing... make sure you have plenty of material to work with... your shop manual states clutch thickness in thousands of an inch or mm... Next removed the contaminants with Acetone... pick a hard surface to lay over a 600 grit black dry emery paper... rotate the clutch plate in a circle... you're just busting the glaze... don't get carried away remove too much material... You should end up with a friction plate looks dull like a new one as opposed to a shinny glazed one... recheck thickness... Finally check the pressure plates for bluing caused by localized heat... make sure they are not warped... consult the manual for a thickness range... now removed the contaminants with Acetone and wire wheeled them to erased the blue and also to generally scuff up the surface... you should end up with a dull surface free of Blue marks... Steps to check your clutch for drag... your gears can't shift smoothly if your clutch is part way engaged... 1 Place your bike on the center stand... 2 Start engine and establish a warm steady idle... 3 Squeeze in the clutch lever and shift into first gear... 4 Hold in the clutch lever and note if the rear wheel coast to stop... if it continues spinning trouble shoot the lever for travel and master cylinder for condition... open the oil filler and look at the clutch pack to note just how far the plates spread apart when you squeeze the lever... Ultimately you want the rear wheel to coast to a stop when the engine is idling and first gear selected with the clutch lever is squeezed in... Link to comment Share on other sites More sharing options...
VIFFR Posted April 1, 2020 Author Share Posted April 1, 2020 2 hours ago, ducnut said: Some thoughts: You may visually compare the aftermarket levers to your OEM levers, just to make sure they’re identical in the important areas (pivot point > inward). Bleed the clutch system one more time. Did you pull out the clutch pushrod and give it a good cleaning? Are you positive your master cylinder seals are correctly installed and there’s no leakage past the piston? I’m wondering if the clutch plates are glazed enough to be sticking together or there’s warpage in them? Drag racing is so hard on clutch plates. Sounds like you’re on the right track with your own thoughts, though. Hey mate thanks for the reply. The clutch has been bled 3 times now so im not going to do it again i don't think. I double checked everything when it went back together with the manual in front of me. Im pretty confident that i got the seals right. I spent 3 years overhauling underwater breathing bottles so I'm pretty confident doing that sort of thing. I'll have a look at how to deglaze the steel plates today, and I've cut myself a nice square of aluminium to use as a flat surface to check for warpage. Im kicking myself i didn't think of putting the stock clutch lever back on first.... Link to comment Share on other sites More sharing options...
VIFFR Posted April 1, 2020 Author Share Posted April 1, 2020 1 hour ago, BusyLittleShop said: ... open the oil filler and look at the clutch pack to note just how far the plates spread apart when you squeeze the lever... Quick reply coz im at work, thanks for a very detailed reply! I did this and it looked like the clutch plates only spread apart in 1 area. The rest were stuck together. I'll do a better reply at smoko. Thanks Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted April 2, 2020 Member Contributer Share Posted April 2, 2020 You're welcome... sticking together is characteristic of a Barnett clutch... its the reason I don't recommend them... Link to comment Share on other sites More sharing options...
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