An ongoing problem with carbed R1. Despite changing the gear linkage numerous times because I thought that was the problem the problem persists (cable).

Getting ready for its MOT jacked it up warmed it up then ran through the gears numerous times (very little throw in gear lever but easily enough) worked like a dream no problems, the clutch doesn't slip when I have taken it out and plenty of travel before biting. Come to take it for MOT today and just stuck in gear after 5 yds couldnt shift it from first (but had the same in other gears before), this is a persistant problem each time I think I've solved it but obviously not.

It felt as if the clutch was causing it, as with the pedal fully down it wasn't disengaging fully and yet when on ramps no problem and the engine was just as hot. Using semi-synthetic oil.

If the clutch is at fault wouldn't it slip when driving even when at the top of the rev range it doesn't? And like I have said adjustment seems ok. I don't want to just throw any more money at it without knowing what could be the problem.
Would appreciate any help as I am not getting to the problem and at a loss now.
Cheers
Jim

Get someone to sit in the car with foot fully down on clutch, then push the clutch lever on engine with your hand to see if the clutch pedal is fully pulling the clutch out.

If the clutch was worn it might slip under power, but releasing fully or not is likely a different problem
With it running and the clutch down, is it pulling you along? REALLY not releasing?
Or just enough to cause drag and stop the clean gearchange?

Thanks for replies guys.

Checked with clutch peddle fully down if there was any more movement available at the clutch lever, there was a little so adjusted that right out so once the clutch peddle was fully down no more movement poss at clutch lever. Result the clutch is on right through the peddle travel (there is a lot of travel as changed pivot points to make it more driveable (joke) .

With 2 of us in it the car was trying to pull away with clutch peddle fully down but just stalled and no way could I change gear obviously. So dont understand how with the clutch adjusted as it is how can the biting point change so much?

Clutch drag for sure

If you've changed the pivots to get a better feel (less on off like becs are ) you need to be sure that its definitely fully disengaging though. It's still what it sounds like.

Is there a clutch pedal stop, to stop you over de-clutching previously?

Otherwise Has there been any work on the clutch itself?

Thanks for reply.

No work on clutch, but did change the pivot point to get more feel. It does disengage at the top of its travel and is fully disengaged. What I don't understand is how it goes from that state to not working at all (i.e. clutch not working with same amount of travel in clutch pedal (sorry for previous spelling, doh!).

You've got a couple of mm free play in clutch arm on engine with clutch pedal up?

yes must be about that as after adjusting about 2 or 3 mm clutch wasnt disengaging, but the problem is that changes and with the clutch pedal fully down the clutch doesn't disengage.

Has the engine stood for a while?

Mine was stuck due to standing over 12months, oil goes like a glue between plates and holds them together.
Pretty easy to strip and clean up the plates to be honest.

Think you might want to pull the clutch then , its not a big job.
I wonder if the baskets very worn or even loose on the shaft perhaps.
If you still sure the clutch arm is moving as far as it possibly can

Yes, it doesnt get used hardly at all I havent the confidence in it because of this problem, although I do start it up every so often (bit of a joke really I built it 6 years ago!). I think your suggestion is a good one and will take the clutch apart and clean it, hopefully I will discover the same oil problem that you did. I will let you know what I find and if I do solve the problem finally.
I really appreciate your help.

Thank you
Jim

Not sure if it's important but in the Haynes manual it says to keep the plates and metals in the same order as they come out if you are reusing them.
If you have access to a vernier gauge its prob worth checking the plates are within tolerance whilst they are out.

Description

Description

The other thing is when refitting make sure you tighten down the spring retaining bolts equally,small turns at a time.
The bolts only need to be torqued to 8NM too.

[Edited on 25/6/15 by CosKev3]

Thanks for the info, I'll be tackling it at the weekend so will let you know what I find.

Cheers
Jim

Get a aerosol of brake/clutch cleaner,the stuff that evaporates quickly.

While the clutch is apart check the steel plates for flatness on a glass plate. They discolour and bow when overheated, and this causes clutch bind as well.

Hi Jim, did you get this sorted. Sounds like a similar issue I had after a rebuild. Part of my issue was the gear linkage adjustment . Have you tried engaging the clutch and pulling on the clutch arm rather than using the paddles/gear lever?

After taking the clutch apart found that all the plates are fine, flat and well within the thickness specified. No sign of blueing, and the clutch nut was tight.

The oil seemed fine as there was no stickiness on the plates, none were sticking together. To be honest I am disappointed as I was hoping I would find something that was obviously causing the problem. So have re-assembled and will attach cable when the rain stops! I am going to change oil and filter and will let you know if there’s any improvement.

As for linkage I have tried everything, bought new cable (didn’t really need it) changed pivot points, used different routes. When you say engage clutch and then move clutch arm are you referring to the arm that changes gear?

Again thanks to all posters for all your help.

Did you lubricate the plates to make sure they weren't at least sticking?

As for gear arm yes if you've still got the short lever that bolts to the spindle that exits the gear box it's worth checking you can change up or down by hand using that once you've got the clutch engaged. Should only need a fairly light push. What I found with mine was a rookie mistake that during the rebuild we'd stupidly rotated the arm a few degrees too far round on the spindle and when operating the cables with the paddles the cable linear movement wasn't matching up with the circular/rotating movement the gear lever needed. Changing by hand at least confirms this and worth a try.