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Dragging Clutch Rev3


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I seem to be having a similar problem as the guys with the Techno in an earlier thread - the clutch on my Y2K Rev3 250 sticks when cold so bad that even in 2nd gear, clutch in on tarmac it locks up when being pushed to free them off. Eventually it releases enough for the back wheel to turn and then I need to find neutral before kicking it over to start.

I have trouble (in fact nearly impossible) to find neutral when it's running so for every section I have to kill the engine if I need to rest unless I have a friend to hold the clutch in!

I've also noticed that in higher gears (4th upwards) it tends to slip although there is no problem in lower gears and in sections themselves, only on long climbs back to the van.

Is it worth taking the clutch plates out and reassembling them in a different order as some have done before or has it gone too far for that and only a replacement set will do?

Cheers

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I was advised of this issue before I purchased my 2003 Rev-3 and sure enough, they stick like glue when cold. I immediately assumed warped drive plates, as they will certainly cause this symptom, but I was told this is not unusual at all and due in part to the material of the fiber plates. Some guys run ATF in the tranny to help it, but I was advised to take the plates out and scuff up the drive plates real good with some wet/dry. Don't be shy about scuffing them up, as this allow more oil to stay within the plates preventing them from sticking. I was also advised to clean the friction plates too, which I assume to mean roughing them up a bit as well to remove any glaze. This was described to sound like routine maintenance. All of this effort would be assuming the plates are within spec and not warped.

Not to dismiss the results that can come from new plates, but I'd measure them before I threw news ones in. I'm new to trials so if this sounds off base from other's experience ignore me. :D

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Thanks bud - got nothing to lose apart for a few quid for the wet and dry paper and maybe a gasket if the original is knackered.

I use ATF as that was recommended on here and it's only done about 5 hours since it was changed.

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my clutch is ok, but it sometimes is reluctant to work when cold but after warmed up its fine. my problem is

similar to yours such as i find it very difficult to find neutral sometimes when the engine is running or not.

any suggestions as to what could cause this?

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my clutch is ok, but it sometimes is reluctant to work when cold but after warmed up its fine. my problem is

similar to yours such as i find it very difficult to find neutral sometimes when the engine is running or not.

any suggestions as to what could cause this?

Sticking plates is a common cause of this, which can be caused by warped drive plates or a severely notched basket. Either one of those scenarios mess with disengagement and keep the plates from separating and spinning freely. Also oil glazing on the friction plates gets sticky and causes the plates to bind together. Lay the bike on its side, pull the cover and remove the plates to check them out. Inspect the surface of the fiber plates and if you have a good flat surface (thick piece of glass or mirror works well) you can check the drive plates for warping. Also look for notching on the outer basket tangs. If notched they can be filed down to get smoother action and a bit more life, but they will notch quicker so you'll eventually need a new outer basket.

You could also have shifter dog or gear teeth issues, which are obviously harder to get at and inspect. Easy to pull the clutch cover and have a look. Good luck.

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Did the deed today - bike on its' side, clutch cover off (gasket was fine so re-used), clutch apart.

Metal drive plates were fine as was the basket. Fibre plates all had bits of friction material in between where they're supposed to be so scraped that off with a scalpel and used wet and dry to rub down the edges.

Put it all back together and hey presto - I can move the bike around in gear with the clutch in before starting it.

Got it running and another revelation - no clutch slip in 3rd and 4th gears uphill.

Still having trouble getting neutral with the bike running though.......and I now have a ticking/rattle when pulling the clutch in with the engine running which disappears when the clutch is out - any ideas?

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Did the deed today - bike on its' side, clutch cover off (gasket was fine so re-used), clutch apart.

Metal drive plates were fine as was the basket. Fibre plates all had bits of friction material in between where they're supposed to be so scraped that off with a scalpel and used wet and dry to rub down the edges.

Put it all back together and hey presto - I can move the bike around in gear with the clutch in before starting it.

Got it running and another revelation - no clutch slip in 3rd and 4th gears uphill.

Still having trouble getting neutral with the bike running though.......and I now have a ticking/rattle when pulling the clutch in with the engine running which disappears when the clutch is out - any ideas?

Not sure about the shifting, which could be something within the transmission unrelated to the clutch. The rattling is the clutch plates, which you have now allowed to free up and separate when the clutch is disengaged. Some bikes are louder than others with this and I'm not totally sure why, but it could be related to tolerances. I use to love listening to the dry-clutch on my Ducati-powered Cagiva. That was a serious rattle, but totally normal.
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I think you'll find one of the reasons the gear shift is difficult to operate is to stop the gearbox changing gear unintentionally from being knocked by a hazard be it tree rock etc.This is intended by design.Particularly dont want to accidentally'find' neutral just before some riding manouvers., ...The clutch mod sounds good.I should try it.Mine is nonexistant when cold. All the best Chris

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That makes sense Chris. Thing is, I watch with envy as riders on other bikes slip into neutral and give their clutch hand a rest whilst waiting at the sections - if I need a break I have to stall the bike and then restart it when I'm ready for the off.

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That makes sense Chris. Thing is, I watch with envy as riders on other bikes slip into neutral and give their clutch hand a rest whilst waiting at the sections - if I need a break I have to stall the bike and then restart it when I'm ready for the off.

I find with my REV3 that 1st to neutral is impossible but 2nd to nuetral is easy. I don't want to over simplify the solution but don't try to go from 1 to zero go 1 to 2 and tap back down - it works for my bike.

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Take a jeweler's file or an ignition file and remove the adhesive between the fiber pads on the fiber plates.

Then look at the tabs on the fiber plates that ride in the grooves in the clutch basket. These are usually unfinished and are the cause of most of the Beta clutch problems. Essentially these are bearing surfaces and when the clutch must engage or disengage these have to slide in the groove of the clutch basket. This is what the plates look like from the factory.

http://newenglandtrials.org/clutch001.jpg http://newenglandtrials.org/clutch003.jpg

Needless to say this is less then ideal as a sliding surface. Imagine as the clutch is engaged these surfaces are torqued against the side of the clutch basket grooves and stick. This makes the clutch slip until the lever is released further and the plates let loose with a snap. AKA light switch clutch. Also why the Beta seems to have a heavy clutch. The heavy springs are there to compensate for the inability of the fiber plates to slide by forcing them into position. Now look at it from the disengagement side. The lever is pulled in but the plates are held in place by the torque forcing the rough surfaces on the tabs into the basket grooves not allowing the plates to slide apart to release the clutch. This is the famous Beta dragging clutch.

Take a fine file and smooth the sides of the fiber plate tabs trying to keep them even with each other so they all contact the bearing surfaces of the clutch basket. This removes the rough edges. Finish with a polishing stone. It's OK if it rounds them somewhat. I've done this on several bikes and the result is a Beta clutch that is smooth and consistant. One of these days I have to write up a good description of the procedure but for now this will have to do. On my bike with the fiber plates cleaned up and two springs removed I have no slip and a light clutch pull that is on par with any bike I've ever ridden. It's a time consuming fix to do but it's free and it works like a charm.

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Take a jeweler's file or an ignition file and remove the adhesive between the fiber pads on the fiber plates.

Then look at the tabs on the fiber plates that ride in the grooves in the clutch basket. These are usually unfinished and are the cause of most of the Beta clutch problems. Essentially these are bearing surfaces and when the clutch must engage or disengage these have to slide in the groove of the clutch basket. This is what the plates look like from the factory.

http://newenglandtrials.org/clutch001.jpg http://newenglandtrials.org/clutch003.jpg

Needless to say this is less then ideal as a sliding surface. Imagine as the clutch is engaged these surfaces are torqued against the side of the clutch basket grooves and stick. This makes the clutch slip until the lever is released further and the plates let loose with a snap. AKA light switch clutch. Also why the Beta seems to have a heavy clutch. The heavy springs are there to compensate for the inability of the fiber plates to slide by forcing them into position. Now look at it from the disengagement side. The lever is pulled in but the plates are held in place by the torque forcing the rough surfaces on the tabs into the basket grooves not allowing the plates to slide apart to release the clutch. This is the famous Beta dragging clutch.

Take a fine file and smooth the sides of the fiber plate tabs trying to keep them even with each other so they all contact the bearing surfaces of the clutch basket. This removes the rough edges. Finish with a polishing stone. It's OK if it rounds them somewhat. I've done this on several bikes and the result is a Beta clutch that is smooth and consistant. One of these days I have to write up a good description of the procedure but for now this will have to do. On my bike with the fiber plates cleaned up and two springs removed I have no slip and a light clutch pull that is on par with any bike I've ever ridden. It's a time consuming fix to do but it's free and it works like a charm.

+1 Yes this is good info. I've filed down the grooves in the baskets to fix dragging and sticking many times, but never the edges on the plates. I've actually never seen plates this crudely finished before needing to have it done. I still have mine apart right now and it looks like the basket has done a good job polishing for me, but the non-load sides are as ugly as the ones in your pics. This must be stock plates in mine. You know if the aftermarket ones like Surflex are better finished? Edited by mrkartoom
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