What a Drag!

[bryan]

The restored LC is nearly ready to go to its owner, however Im having a problem with the clutch dragging and I cant get the bike out of first gear while the engine is running. While riding it changes up and down the gears with no trouble.
I have just fitted a new basket, as it was groved, but its still dragging. Have also fitted new fiber plates and a replacement used set of metal plates from Norbo.

I believe that the whole basket and primary drive spins between the 2 thrust washers and the centre spacer that go onto the Imput shaft, so has no effect on the operation of the clutch stack between the inner basket and the cover, so any ware on those parts will not cause this problem.
This only leave the metal plates or the springs as the cause, all other clutch parts are new, so Ive either got warped plates or incorrect springs getting coil bound and not allowing the clutch to fully disengage.

Has anyone had the same thing and what was replaced to resolve it, as another member is having the same problem on a YPVS engine.

[arrow]

Never had a problem with slipping, dragging or finding neutral at anytime. Try a bit of "hard use" to smooth the new plates out a bit.

[bryan]

It shouldent need that rearly, it should work correctly even if its new plates. I also remember that the inner basket had some groving on the spline that the metal plates slot into, and this could do the same thing as the outer basket and not allow the plates to total release.
All in I think the new metal plates, centre spacer and thrust washers and new springs are about £120 and the inner basket was about £30 as I had to replace mine a few months ago, so might just have to replace it all.

[arrow]

I had to have a new outer basket on mine, fell off the bench and broke a tang off. £270 from Yamaha!

[bryan]

£135 to rebuild it with the bits above, they ar £302 as of last week for Yam one.

[Norbo]

get a file on the groovs on the basket to smooth them out mate

[bryan]

That's been done in its past already and there are still groves in it, some times you just got to fit a new part.

[muttsnuts]

check your clutch spring lengths and also the clutch spring bolts, I have the exact same issue and thus far the only things left to change/check are the clutch springs (heavy duty ones) and the bolts.

I suspect its a combination of my springs and bolts are the fault, if the bolts are too short they clamp the springs up too much (coil bound), the bolts are a critical length and when they "bottom out" that's them seated, hence why the torque settings are so low for them as the bolts bottom out.

If you can wait a day or two I will be doing mine and have a few things to try, but my money is on the springs being sligthly too long so are getting coil bound and the bolts sligthly too short, which won't help at all.

A quick and easy check is to adjust your clutch cable so that the clutch is fully disengaged all of the time, start the bike bike and see if you can go through the gearbox and select neutral etc, when I say adjust I mean adjust it so that you don't need to pull the clutch lever in, so basically you don't have any drive when the clutch is out. If you can get all of the gears and neutral then its for sure the clutch and not the selector drum or selector forks, which can also be a problem, if you still can't get neutral then it could be the springs and bolts (mine is like this) or an issue with the gearbox/selector drum/forks etc

HTH

[bryan]

I am thinking it could be the springs getting coil bound, however these are either YPVS springs or the HD springs I had in my LC with no problem, I just not sure which but they are the lenth of YPVS ones. Have stripped it all out again tonight and checked the inner basket.
I may well just replace the centre spacer and 2 thrust washers while it appart, and get 6 new LC springs and try that.

[muttsnuts]

Hi Bryan, well I've stripped mine out and taken a good number of measurements etc, basically I reckon it could be a coil bound issue, I think the springs I have fitted are getting coil bound.

Basically the numbers stack up as follows;

Standard Springs Dimensions (NEW)

Length = 34.90mm
Coil Gap = 3.50mm
Coil Diameter = 2.30mm
Number of coils = 6
Recess depth in clutch outer plate = 23.25mm
Clutch Rod Travel (max) = 2.50mm

Therefore

Total Coil Gap = 6 x 3.5mm = 21.00mm
Clutch clearance = 23.25mm - 21.00mm = 2.25mm

So using the figures above I got some feeler gauges and measured the gap between the clutch outer plate and the top clutch plate, I could only get 1.2mm in on max clutch position, therefore I am short by 1.05mm clearance, so I needed to find out where the space had gone

So far, I've found that the uprated clutch plates I got off Norbo are 3.1mm thick, as opposed to 3.00mm, so I've lost 0.7mm clearance (due to 7 plates), and I think the rest has been lost because the coil diameter on my springs is 0.05mm thicker and 7 coils instead of 6 coils, so that's 7 x 0.05mm, which equals 0.35mm, so 0.7mm plus 0.35mm = 1.05mm, which is exactly what I've lost in clearance, so I am just sorting out some 1mm washers to put under the clutch bolts (but fit inside the springs) so that the springs are being compressed 1mm less, thereby giving me the desired 2.25mm clearance

Once I've sorted that today I'll give it a go and let you know if that has fixed it nor not

HTH

[marsbar350]

bloody hell dave
gunna have to buy a micrometer
thorough work aswell.good stuff

[muttsnuts]

you ain't seen the calculations I am doing at the moment for the stack height, which is where I think I need to make sure things are all ok, as that is the critical thing in the clutch, if that is wrong then no matter what you do with the springs etc it will be wrong, so I am just sorting out what mine is versus what an original Mr Yamaha is, which will also tell me a few things !

BTW - I've still got your shocker hewre, I sent you a picture etc, you still want it ?

[marsbar350]

yes mate
will have to post it as im not up your way soon
PM you later

[muttsnuts]

ok, done some more checks etc, and found a few other things out.

I've stripped 3 clutches now to see what if any differences are and well, its interesting, one clutch has a set of springs with 8 coils, one with 6 coils and one with a mix of 8 and 6 coils !

Also, looking at the baskets, I have 3 different ones with different part numbers, they all look and pretty much measure up all the same, none of which are marked up 4L0 ironically, so all I can draw from this is that over the years allsorts of things must have been swapped/changed/altered etc, all 3 clutches have come out of LC's, so I am a little lost as to the correct combination now as both the parts list and workshop manual don't go into enough detail to advise.

Ideally I need some one who has brand new clutch components for a 350LC to list out what the various measurements/configuration is.

In the meantime I've gone to a stack height of 28mm as that is what it should be according to the measurements I have etc, and I am also going for a 2.25mm to 2.5mm clutch clearance and then trying it from there, will try and get it done today, but its beer o clock soon, so it might be later tomorrow before I report back

In the meantime, if anybody has some or all of the various clutch components new from Mr Yamaha and don't mind posting up the various dimensions and also any part numbers printed on the parts themselves (not the ones on the bags) then that would be most helpful !

[pepsisteve]

1st thing i would do is get the steels out and check them on a piece of glass or the like, if you can get neutral with the engine off then it is clutch drag problem not selectors or drum

[Denzil]

I have the similar problem with my N2 Ypvs in that I can't get neutral when engine running. It will change up and down no problem but won't go in to neutral from 1st. When I pull the clutch in its like the clutch won't pull in any further plenty of play on the cable but doesn't make any difference. New clutch from Norbo no grooves on basket but after reading Muttsnuts fascinating account of spring lengths I think I may have a problem with mine. 3 springs are long and 3 are short. As you have replaced with new Bryan would a new set of HD springs sort it. ?

[Deleted]

Me and kev sorted my clutch today. I changed the clutch plates with heavy duty plates plus three yzr500 clutch springs from norbo and ever since there has been slight clutch drag and at standstill couldn't get it out of first gear never mind into neutral. So stripped her down and found that two of the steels were slightly warped, Looked through kevs bits and found two straight steels and also removed and binned the rubber damping rings, put it all back together,adjusted clutch started it up and even without the gearbox oil getting warm it went nicely into first, let the clutch out to move forward, stoped and hey presto it went straight into neutral. Let the engine warm up properly and there is no problem getting neutral now

[bryan]

Ive had the thick metal plates issue with a engine rebuild b4, just went to new Gen Yam parts and was ok.
Ive possibly caused this problem as I had the springs and to save the cost of new ones I told him he could have these, wish I had just ordered new springs as they are only about £3 each now. The metal plates though are £12 each so thats why I got a used set from Norbs.
As far as I know, all baskets and centre boss, centrs spaceR, thrust washers and clutch plates are the same across LC/YPVS/Banshee and are all interchangable, so not an issue. LC has different clutch cover with no adjuster and its own seperate mushroom pushing cluth to disengage, but basicly the same.
I had 3x TZ700 clutch springs in my LC and it was stiffer but had no issues with drag, also had 6x HD springs and no issue with drag either, so Im back to thinking metal plates now after thinking its the springs coil bounding. Even if the HD springs were the YPVS ones, and the HD ones are in my LC, I think it should still not cause the dragging as all the baskets and centre bosses are the same.
Im thinking do the springs and if it still dose it replace the plates with new so I know which one was the cause if it cures it.

[bryan]

Just re read and I think you are wrong on the bolts Mutts, they tighten on to the top of the 6 posts on the inner hub so bolt lenth not the issue.

[muttsnuts]

Hi Bryan, yes, they bottom onto the top of the posts, not the bottom of them, so unless they are too long they will not cause an issue, so yes, you are correct - working on too many different bikes at the moment I think.

Anyway, I've got mine back together and after putting some 1.2mm washers under the bolts (so as not to compress the springs too much) I now had a 2mm clearance and can select neutral with the engine running, I've not had chance to run it down the road yet to see if it slips at all, but it shouldn't as all I've done is releaved the compression a tad on the srpings, they now have clearance to compress and the clutch lever is a lot easier to operate.

Agree about the steel plates, well worth checking them for being warped, or damaged or worn, think they sre between 1.13mm and 1.15mm thick looking at my notes, I just went through all of my plates and found 6 of the identical thickness and tried to get as close as possible to a stack height of 28mm, I managed to get to 28.35mm (but given the heavy duty plates are 0.1mm thicker), then I've managed to get it pretty close, so I just adjusted the thickness of the washer required to give me the 2mm clearance I was looking for.

I think it might work with less clearance, but not much, given there are 13 plates in total, having it much less brings into the question how thick the oil is, how much drag it causes etc, etc

HTH