So was out in the car for its first proper drive since the busa conversion and seem to be having some issues with the clutch.

When I'm in 3rd or 4th and at full throttle at about 7k rpm the revs climb quite fast the settle again then climb normally. Once the car gets really warm it does it in most gears. Once left to cool the car drives normaly again for a bit. Does this mean kackered clutch plates? If so should I be looking at uprating them or just replace with OE?

Cheers

Iain

Have you fitted uprated clutch springs yet?

Nope. It's just as it came out of the box I think. MK fitted it so need to check.

You'll need updated clutch springs mate mine slipped too I bought SBD Motorsport turbo clutch springs about £60 I think
Sorted it right out also Nader the clutch easier in traffic as well !!!
See my blog for part number

Defo fit the springs , but also check the the modified clutch slave cyclinder rod is the correct length , if it's slightly too long the clutch will remain slightly open and slip
Just make sure the when your foot of the clutch the rod is not under pressure

Can anyone recommend a place to buy the springs? Are they easy to fit?

You can get them from places like , AB Perf, Big CC, SBD, Extreme etc and they are easy to fit.

The oil you use makes a difference also. What are you using?

Cheers, Nick

[Edited on 15/6/12 by Nick DV]

Do not forget that the oil can have a detrimental effect on bike clutches. Top spec car oils will cause wet bike clutches to slip. I've seen this over and over again. Use an oil that is designed for bikes with wet clutches.

In a number of cases an oil change has fixed the problem.

You may already have the right oil... In that case forget all this and get your uprated springs

Has the engine been run on 5w30 'race oil'? If it has then it might well be time for new clutch plates. I would be fitting new clutch plates anyway though if its been slipping a lot as they could well be damaged, they're about 200 quid from Suzuki.

Other than that, check the clutch push rod and make sure it is the correct length!

No idea what oil is the car, whatever MK put in it. I'm assuming it's the correct kind.

Ok, so might be worth an oil change anyway. Which oil and how much does it need to fill it?

Might as well do clutch plates, springs and oil at the same time.

Iain

If you've got £200 to spend then change the plates. I'd strip, clean, examine and measure the plates first. The uprated springs though are worth fitting while you're there.

The oils that are sold for bike engines are the ones you need. I have always used Silkolene in the past and never, ever had a problem. The GSXR 1000s we used in World Championship sidecars ran to over 200 bhp on a 10", very sticky slick and the standard clutch never, ever gave the slightest problem.

HTH

I've literally just ordered some uprated clutch springs from RPE. They said they never have any issues with these even on the 1500cc motors.

Listen to my words carefully & check through.

Don't worry about your oil. If it is so marginal the oil causes slip then there is other issue anyway.

If your clutch has the anti ramp ring then check it has extended heavier springs. Most competitive engines have a locked ramp ring or billet or welded centre. They will slip with stock length springs as they don't apply the correct pressure.

Check if you have a stock sprocket/ slave cover that it is not cracked. Many do crack.

If your clutch pack has worn down in its installed height you don't need to change the entire pack. You can regain the correct stack height to preload the springs by removing either a thin friction or steel & replacing with a thick alternative to rebuild the height. Much cheaper.

As a car check your push rod length & ensure it is not holding off the clutch, equally your master cylinder is not oversized. I have seen many cars with incorrectly sized master cylinders.

Barnett heavy duty springs are only about £18. You don't need special gold dust springs at silly money. Decide though if it is ramp converted before choosing them to determine the length required.

The stock cutch in a bike can hold 250hp with no special springs or plates so either it has worn through milage, worn from power, or worn through a miss match of parts operating it.

Remember to clean the sump out to stop oil starvation from a blocked oil strainer.

Al best

Sean

My uprated clutch springs from Radical Performance Engines were £18 in total.

The oil needs to be JASO-MA basically.

Im sorry I have very little knowledge of the engine so excuse my ignorance (i've only had the car back 1 week).

How can I tell if my clutch has the anti ramp ring? Im pretty sure the clutch assembly is stock bar the clutch slave cylinder. if I'm going to remove the clutch plates i might as well replace them at the same time as the springs. Do you sell uprated plates also?

Am pretty sure the master cylinder will be ok as it was fitted by MK.

Sump is a new swinging pickup type so should be fine. Will check the push rod length tomorrow.

Cheers

Iain