Couple of problems with my 97 vtr f.

[Antjp]

Recent problem is my sprag clutch. Has anybody posted any details in how to repair. (I can't Start every time as I get a screaming sound. Getting worse)
My second problem is my clutch, although it works with no slippage. When I want to do a hard take off, I will rev not too high, just enough to get a powerful take off without stalling but it grabs and wheelies. So it tends to ruins my starts. I don't race a lot so it's no major concern. But just wondered if anybody has encountered this. Under normal use it doesn't happen.

[Ckennedy]

The sprag clutch I will let someone else answer but as for the clutch grab, unfortunately you'll have to put up with it. There isn't a cure as we don't know what causes it. May things have been tried Inc a cable conversion and the bike will still do it. You either get it or you don't

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[Wicky]

Re. Sprag clutch > search for 'sprag' in the top right search as it's a area previously covered.

[Antjp]

Thanks guys. I will search for sprag now in the search. As for the clutch it's been like this for the 8 years I've owned it so I am used to it. Just didn't know if anybody else's bike did the same. Cheers Ant

[sirch345]

Moved from "The Welcome Inn" section,

Chris.

[AMCQ46]

tony.mon can advise on the sprag clutch, he has replaced a few of them.

clutch screech and grab is variable from bike to bike, but we don't know what the real root cause

[Antjp]

I am trying to access my sprag clutch and I can't remove the alternator rotor. I've read posts explaining using a iveco or MAN wheel stud. Am I right in saying by threading this in it should come off?
Cheers

[Ckennedy]

Yes one of those wheels studs will do the job. If you can't get hold of one let me know as I have some in my tool box. I can cut the head down to the right size for a spanner of yours if you cover postage.

You will have to give it a bit of a tap with a hammer to get it to come loose unless you have an impact gun to hand which will pull it off itself.

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[lloydie]

I am trying to access my sprag clutch and I can't remove the alternator rotor. I've read posts explaining using a iveco or MAN wheel stud. Am I right in saying by threading this in it should come off?
Cheers

http://www.ebay.co.uk/itm/291152740203

[Antjp]

I have removed the Allen bolts. I have removed the 17mm center bolt with impact gun. So I thread in extraction tool into where I've removed the 17mm bolt. And gun clockwise. Then alternator rotor comes off

[Roger Ditchfield]

THERE IS A CURE for clutch snatch off the line under racing conditions but it will cost a fair amount and you have to decide if it is worth it for you. It was for Revolution Racing.
Here is the answer to your problem.
1) "Lazer" cut a number (say 6) steel clutch plates out of Spring Steel. Make them the same thickness as the OEM steel plate
2) Pressure dish the plates by 5mm.
3) Find a spring maker to heat treat the plates so they are now a diaphragm spring plate
4) Rebuild the clutch stack substituting one or two of the OEM steel plates(depending on the power output of the engine) with the new Spring Steel dished metal plates.
You now have a "Diaphragm" clutch.
Problem solved
Over time the plates will lose their spring strength that is why I recommend you make six of them
If you wish to discuss this in more detail please ring me on 07970 915259 anytime
Hope this is of help
Roger

[Antjp]

Thanks for the information on the clutch Rodger. If I ever need work doing on the clutch I will consider this.
At the moment my clutch is Working and I don't race often. I have got used to the way this bike is so it's ok for me. I needed a change of underwear when it happened for the first time.

[Jamoi]

THERE IS A CURE for clutch snatch off the line under racing conditions but it will cost a fair amount and you have to decide if it is worth it for you. It was for Revolution Racing.
Here is the answer to your problem.
1) "Lazer" cut a number (say 6) steel clutch plates out of Spring Steel. Make them the same thickness as the OEM steel plate
2) Pressure dish the plates by 5mm.
3) Find a spring maker to heat treat the plates so they are now a diaphragm spring plate
4) Rebuild the clutch stack substituting one or two of the OEM steel plates(depending on the power output of the engine) with the new Spring Steel dished metal plates.
You now have a "Diaphragm" clutch.
Problem solved
Over time the plates will lose their spring strength that is why I recommend you make six of them
If you wish to discuss this in more detail please ring me on 07970 915259 anytime
Hope this is of help
Roger

There's a cure!!

I'd love to cure my clutch grab, I had been looking at the Sigma slipper clutch in the hope it might solve the issue.

At least Roger/Revolution's solution is guaranteed and tested modification.

Not sure anyone here has tried the sigma slipper clutch yet?

[Roger Ditchfield]

My solution was part of our development program and work perfectly on our race bikes. It took a bit of organizing and I was lucky to have the "contacts" that could do these things for me back in the nineties.
I have used Sigma slipper clutches on several models of racing bikes including SP's in more recent years and found them to be good and reliable if correctly installed. Hope this helps in your deliberations

[Jamoi]

My solution was part of our development program and work perfectly on our race bikes. It took a bit of organizing and I was lucky to have the "contacts" that could do these things for me back in the nineties.
I have used Sigma slipper clutches on several models of racing bikes including SP's in more recent years and found them to be good and reliable if correctly installed. Hope this helps in your deliberations

Thanks for your info

Certainly good to hear some reassuring feedback on the Sigma clutch.

Also any info on the 90's race bikes is always interesting to read.