Anyone experience this and can advise...

[mhsilverw]

Went for a ride-out on the 350 today, and managed to get some numb toes and blue fingers....was quite chilly but very enjoyable on my 'local' TT!

Did have an odd moment (or two) that has me puzzelled as to root cause.

When accelerating in one of the higher gears, when the tach indicated around 5500-6000rpm the engine note changed (and I wondered if the clutch slipped a little?).

I throttled back and then it went through that part of the (indicated) rev band without a repeat....so did another 20miles or so.

Then on a downhill stretch of an A road, again with the rev counter showing around 6000rpm (on the veglia) it did it again..engine note changed before settling down again. Once revved past this the tacho crept up beyond 6K heading to 7K...and the speedo followed suit a bit eventually indicating around the 80mph mark (so most likely around 70 or so if these instruments lie somewhat!) with me sitting more-or less upright.

So it did this twice in about 50 miles and both times when accelerating...

At other times gears seemed to engage normally and ok and clutch showed nothing untoward at junctions, roundabouts and traffic lights so stopping and pulling away and changes during the ride.

Is this an indicator of something looming - I know my 'digits were a bit cold' (- and after riding yrs ago on RD400's tend to keep two fingers on the clutch lever in case it needed whipping in) but dont think I pulled the lever in by accident even with my muffly winter gloves on.

I did check the lever free play when I got home and adjusted the position of the levers a bit better to suit my posture, and looked at the clutch lever which seemed to move freely where the cable connects to it at the engine end. Can't recall seeing any oil coiming out of the clutch cover, but didnt take that off - too many chores following my ride-out.

Guess next spell in the garage will be to have a look - but wondered if this 'behaviour' engine-wise rang a bell with anyone...and if so possible root cause, solutions.....

Regards

Mark

[unreal]

Hi Mark, I recently had a similar behaviour on my Sport. Clutch felt fine in use but felt like it was slipping at what is probably max torque. I found two friction plate were worn and the rest were what I would call grubby! I replaced all plates and all is good now. So it may be worth popping the clutch out and have a look as it's a simple job and a clutch sets not that expensive if they need replacing.

Good luck

Simon

[MarkB]

Hi Mark

I had a similar issue with my Sport - very slight slipping under heavy load in the higher gears. It turned out that the clutch had got some oil in it; not enough to leak but just enough to make the plates slippery. A good clean of the plates sorted it out quickly.

Cheers, Mark.

[mhsilverw]

Seems like some investigation of the clutch plates seems a start.

In terms of cleaning plates if needed what works - petrol and a wire brush

Hopefully it's not a seal on the way out (there are 3 arent there lurking?) and I assume/guess for those one needs special tool(s) .

Is there a tool loan scheme?
or does anyone 'make' these at all ?

.....someone skilled with metal and handy with their hands or spares lying about?

A fruitless search on fleabay didnt locate any just now.

Regards

Mark

[unreal]

Brake cleaner works pretty well. I have also heard some boil them up with detergent but I wonder of a risk of delaminating.

Simon

[mhsilverw]

Seems one thing is 'clear', I can/have described and encountered 'clutch slippage'.....

thx for that, so now I know what I can clean the bits with, if needed......

Has anyone got the 'specs' or length of clutch springs (what they should be - and how to test) and are there 'spring cups' that can distort/lengthen (what should these measure?).....

Looks like my looming spell in the garage could be:

1. check freeplay (cable - both ends) - simples....
2. check clutch housing for oil - hopefully simple...
3. check springs - getting scary, if I can find a screwdriver to butcher; and the sizes how to measure - at rest
4. check spring-cups - just measure these
5. check/clean plates - and try and put back in right order/the right way round!
6. Help!!!!!!

I seem to recall a recent piece in the ATG about stripping and rebuilding the fuel tank on a Dart. How about a numpties guide to a clutch overhaul

Like Clint Eastwood says: a 'man' has to know his limits.....

and then at step '6' I guess if still stumped or no improvement seek help from the 'cavalry' , or folk who have the right tools and knowledge....NLM I guess!! [.....for seals, thrust bearings, pushrods etc, any clutch drum in-out or side-to-side play..or more involved stripping and replacement and anything else lurking]

[unreal]

I use one of these:

http://www.ebay.co.uk/itm/BSA-TRIUMPH-T ... 687wt_1398

I modified it by opening the centre a tad and shortening the blades to stop it bending (also it makes the blade thicker and fits better) and it now works a treat.

From what you described it doesn't sound too bad, hopefully a good clean and maybe new plates should have you back on the road ATG!

Good luck

Simon

PS If the bikes left on the side stand all the it's more likely that there may be a touch of oil trying to seep? Just a thought...

[trinder]

Mark,

Dont be frightened by dismantling and reassembling the clutch it really is the easiest thing to do. The whole job should only take you about 10 mins. I can let you have the spring length from the manual when I have looked it up. You can also buy a tool that fits the slotted clutch retaining fasteners from Jampot Spares as they are the same size as on a Matchless clutch for about five quid. when re assembling, setting up the clutch is easy.

Neil

[72degrees]

My clutch has the 'WeeVee' hex head spring nuts which makes life even easier. The only other thing required if also doing the oil seals or adjusting the shimming is a clutch centre holding tool. It can be acheived by cunning and slightly brutal use of a large pair of slip joint pliers but I use an old steel plate bolted to a length of steel flat stock. It lives in the special tools drawer along with the home made alternator rotor holder and the custom modified valve spring compressor - a genuine rotor puller is in there though!

[EVguru]

In terms of cleaning plates if needed what works - petrol and a wire brush

Petrol is a poor choice as a cleaning solvent.

It was a dodgy enough practice years ago, but modern fuel contains quite a high proportion of aromatic components like Zylene, Toluene, Benzine, Methanol or Ethanol etc.

Most of these are toxic, if not actually mutagenic or carcinogenic. If it weren't 'grandfathered' in, there's no way untrained people would be allowed to handle this stuff. You can get quite bad chemical burns from petrol and people have actually died if enough of their skin is affected.

Besides all that it will leave a residue behind.

There is this stuff called 'Brake and Clutch Cleaner' you know.


With the clutch cover off you'll soon see if you've got much oil about.

Start by just taking the plates out, for which the only special too needed is the slotted screwdriver. I prefer to use a 'bit' that can be used with a ratchet handle. A dose of penetrating fluid some time before starting is a good idea and perhaps even some heat from a hot air gun. The spring screws can sieze onto the studs and there's a danger of stripping the thread that holds the stud into the clutch drum. If this happens, the stud usually ends up spinning in the drum and you will have to hold the screw with grips whilst you drill out the stud.

Take off the pressure plate, springs and cups. The ends of the cups may show bright areas indicating they've stretched and have made contact with the clutch drum which will have similar marks that you can see once the plates are removed. You can fix the cups by squeezing them lengthways in a vice, but make sure you have them installed in the pressure plate as you might not get them through afterwards (they will tend to bulge a bit on the end as you re-compress them).

Getting the plates out can be tricky, particularly if they're stuck together. Possibly the easiest way is to lay the bike over and let them fall out onto a pile of rags. I have an old small screwdriver gound into a long thin blade with a little lip on the end to 'hook' the plates out. Before you bother with much cleaning, measure the friction plates. If they're near their wear limit it's best to replace them and I'd replace the lot, rather than just the friction plates. They're not that expensive and you now have some steel plates to make a clutch holding tool out of. Whether the steel plates are used or new I like to deburr them by rubbing them on 600 grit wet and dry on a surface plate (any smooth hard flat surface will do). If the friction plates are oily and are going to be re-used I'll start with washing up liquid and a good stiff nylon brush before leaving them to dry and then removing any remaining contamination with brake and clutch cleaner.

There are a number of places you can get oil leaks from. First of all there is the clutch pushrod, the nut that holds the clutch drum on has a replaceable seal in the end. Sometimes the 'mushroom' lifter shaft is worn or scored and should be replaced along with the seal. With the plates out you can knock back the locking tab and unscrew the nut. If you have an air or electric impact driver you can remove the nut without a holding tool and you can also get the nut off by putting the bike in top gear and getting a helper to apply the rear brake. Behind the drum is the thrust washer, Bronze on early bikes and nylon on later/upgraded machines. You can now see the seal in the clutch basket which runs on a sleeve on the gearbox input shaft. The sleeve should be sealed to the shaft and the manual says Blue Hylomar (the ONLY place you should use Hylomar in the engine). I use a very small bead of silicon instead. If you can see oil coming from behind the clutch basket, then them the main seal may be at fault. It could also be that the oil level is too high and/or the bike has been left on its side stand a lot. Although the seal is old and tired on my 77 Sport, the only time I get any leaks is at the track day when the engine is very hot and I'm using the side stand because the centre stand is wired up. Getting the clutch basket off can be tricky. Often the easy way is to remove the side cover and drive the locating dowels through into the primary gear. The dowels can be driven back the other way when re-assembling.

[mhsilverw]

EVGuru - fantastic notes....ever thought of re-writing the manual - very informative and useful. As well as other posts/comments and encouragement(s).

I have taken the outer cover off and a trace of oil at the bottom of the cover - but not the 'Amoco-Cadiz' . Clearences at handlebar and lever end (5mm & 15mm) respectively.

Once I have a tool to undo the clutch springs I will try to get at plates and springs. I note the use penetrating flud [hopefully these will be 'ok' and not seized] and the use of brake/clutch cleaner (not BP's finest) and cleaning approach....

Hopefully I can get as far as taking plates out (measuring) and cleaning these as well as checking springs/spring cups. I gather the bike had stood a while so hoping its just dusty or glazed through lack of use (prior to its arriving end of last year) and any lay up it had again; hopefully the trace of oil is workable: as I say it wasn't 'dry-as-a-bone'.

Thx again for the advise.

Thats another thing about the wee-vee. Not only are the bikes great...so is the MRC and the helpfullness of fellow owners/enthusiasts/sufferers (delete as applicable!).

Mark

[EVguru]

Clearences at handlebar and lever end (5mm & 15mm) respectively.

Set the gearbox lever as far out as it will go with just a little clearance to the outer case.

You have to keep an eye on it as it moves further out as the clutch wears, but the clutch usually woprks better that way.

[mhsilverw]

...a continued saga of investigating my slipping clutch (at max torque)...to initially try some cleaning. Have I been floored at the first hurdle...seems so at the moment.

How tight are the clutch spring nuts

....I wonder if I will have to admit defeat as it seems the clutch will not come to pieces easily.

I squirted some more penetrating fluid on the screws (thats some last fri night, Sat and Sunday and again tonight) and armed with a loaned Stanley ScrewDriver (a great big long screw driver so assume lots of leverage at the working end) with the end doctored to suit (thanks Mark) the screws (none of them) budged a bit.

Is there a technique I am missing or is it time for the cavalry?

M

[mad muller]

sounds very frustrating, they should undo with a decent slotted screwdriver, unless totaly seized on due to rust etc, or possible loctite has been applied to threads you could try some local heat and try turning them inwards and then try backing threm off, go easy on the heat as not to damage clutch parts if they are as tight as you say theres a danger they could snap off the drum ,penetrating oil and patients is the order of the day stick with it. muller.

[72degrees]

A miniature blow torch can be useful or even better a small gas powered hot air gun (attachment for a Powercraft gas soldering iron) to direct heat to the correct place. Plusgas is the one true penetrating fluid, though I've had good results with "Shock & Unlock" (particularly for freeing needle roller bearing cages from suspension linkages). Heat , squirt, heat, squirt, apply screwdriver. Repeat. Beware naked flames with oil sprays!