www.zxrworld.co.uk

yeh, its a ZX4 engine, the engine number being in a different location say's definitely, i checked on mine earlier, and its the same, the "flat" that zxr's have the number stamped into isnt even there.

so, its a ZX4 engine, with a ZXR sump and random clutch/genny covers.. and the original camchain tensioner.

zimm wrote:and an early non-kbatl clutch,

you've got me wondering now whether the clutch in my H1 motor is the original, since without taking the basket out (ie as in the photos posted above), both of mine look the same. Might turn out I've got the KBATL clutch in both motors.

That would be quite useful actually, I could play around with one of them to see if I could make it work properly, and still have a good one.

now this may sound thick,

but what does it mean to get the slipper clutch working properly?

gem

You can adjust the amount of slip when you roll off the throttle so that the rear wheel doesnt lock up at high engine speed

right,

cuz i can drop the clutch at most speeds on my 7r and the rear never locks

i havent tried it at really silly speeds, but why would u need to on the road?

gem

IMO (naturally) there's absolutely no need for a slipper clutch on a 4-cyl 400cc bike on the road, and probably only marginal benefit on the track. I have got the back weaving while downshifting, particularly on track, but not to a worrying degree.

However the engineer in me would like to see if you can get it working properly. There's probably not a lot that you can really change other than the thickness of the steels, but I'll get one of them properly apart at some point and have a look.

I can't remember if it was zimm or sloweracing that mentioned having ridden one once that worked so well that you couldn't bump start it, but it would never slip on the power. I'm pretty sure you could tune any ZXR clutch to work that well, and I'd like to work out how.

Gemini wrote:right,

cuz i cant drop the clutch at most speeds on my 7r and the rear never locks

i havent tried it at really silly speeds, but why would u need to on the road?

gem

Thats cos the 7R has got a slipper clutch mate

I managed to lock it up last summer one very early morning down a link road near me, but i think thats cos i changed down far too early and while i was braking pretty damn hard and it nailed the limiter.

RedexRobB wrote:
Thats cos the 7R has got a slipper clutch mate

so's the zxr400?

gem

deviant wrote:IMO (naturally) there's absolutely no need for a slipper clutch on a 4-cyl 400cc bike on the road, and probably only marginal benefit on the track. I have got the back weaving while downshifting, particularly on track, but not to a worrying degree.

However the engineer in me would like to see if you can get it working properly. There's probably not a lot that you can really change other than the thickness of the steels, but I'll get one of them properly apart at some point and have a look.

I can't remember if it was zimm or sloweracing that mentioned having ridden one once that worked so well that you couldn't bump start it, but it would never slip on the power. I'm pretty sure you could tune any ZXR clutch to work that well, and I'd like to work out how.

yeh., was me, it was an L engine in an H2 chassis.. bump starts were almost impossible, but you could bang it down the gears and dump tyhe clutch and it just kinda went "whooooosh" and sorted itself out. RMKD's bike runs a starter for the same reason

steel thickness and attention to the ramp angle is what changes how well it works. dont know much more than that. I can see a benefit, but ironically more on H's than L's, as the H's lower 1st gear does get the back skipping about a lot... mainly its on track though.

Hi,

I found no problems at all bumping my L2 with the slipper clutch, I just needed a bloody great steep hill so I could change gears from 1st to 2nd and then 3rd. Bumping the zxr400 in 1st is near enough impossible. The bearing that makes it easier to put the bike in neutral from 1st gear when stationary is the reason it's hard bumping. You'll find that it's impossible to put the bike above neutral when stationary.
Trying to get the giraffe in 3rd gear ready for a bump start is like trying to get blood out of a stone.

Regards

Rich

stock settings for the slipper clutch are so tight, it might as well not be one, which is how people dont know they have one.


whats so hard about bump starting in 1st ? i've never had a problem, even the mrs can bumpstart hers, and she's only 5ft 3" !

now try bump starting a ducati ..

Gemini wrote:

RedexRobB wrote:
Thats cos the 7R has got a slipper clutch mate

so's the zxr400?

gem

It was just this statement, you said it (i think) as if you couldnt understand why it never locked up:

cuz i cant drop the clutch at most speeds on my 7r and the rear never locks

ah that would have been the problem with mine then, i didnt even think i had a slipper but i must have. you just couldnt get it to bump at all in first but you couldnt get it into 2nd without some movement either. tried to bump it afew times but to no joy.

put cant when i meant can, changed now

gem

Hi,

So if I shift down quite quickly, I'm guessing the back end will lock up correct? People keep saying to me "swap the clutches over" to be quite honest, I don't really care as I'm not using the bike for racing which is really what the slipper clutch is for right? Anyway, the engine is in and is all hooked up, all she needs now is water and fuel to test



Oh yeah, got bored 1 night so I decided to polish the cylinder head.


Regards

Rich