Check belt specs - 'tis possible that the belt is slightly longer
Won't take much to have an effect on the gearing...
Belt will still feel tight - just sit slightly different between the front and rear pullys...

it sounds like the clutch springs are not allowing the clutch shoes to move out and engage the clutch bell, or could be the other way round, clutch springs are too weak and engaging the clutch bell too early so you dont get the slip required on the clutch bell.. i would think that this is the place to work at, if this was mt scoot

Thanks for the replies.
To assist a resolution,
Before I stripped it down it was fine!!
Suggests to me that I've b@@ggered something up.
I've looked at the variator rollers and they need changing, they're squared off in places and the surfaces are not smooth. I'm about to order some.
I'm also researching the drive belt spec to ensure the one I have is correct.
I'll let you know how it goes, thanks.

Very interesting....
Took the variator unit down to local bike workshop & explained the predicament.

After checking rollers etc he advised it was either the clutch not engaging correctly or "had I tried the original belt again to ensure it wasn't the new belt"?
So, got home, refitted existing belt and bike works fine.

Ebay dealer hasn't supplied correct belt. I'll contact them to see what they have to say!

I've been reading this with interest before I clean up my K9 400, thanks for posting. The Suzuki belt is about £150.00 for a K9 from a main dealer.
The belt has changed between models

good job... when something goes wrong we all tend to think of what it could be instead of thinking what have i changed lately, i will have to embed the statement into my bonce

Dave Weller wrote:I've been reading this with interest before I clean up my K9 400, thanks for posting. The Suzuki belt is about £150.00 for a K9 from a main dealer.
The belt has changed between models

Yes Dave the OEM belt is expensive but at least it'll fit!!

And they tend to last a lot longer than aftermarket belts too!

Having refitted original belt I then get an FI light

However, bit of research and I buy the dealer mode switch and fit it today. C44 sensor fault.
Anticipating this (I replaced the exhaust recently and the sensor was filthy) I'd bought a blanking cap and the connector that allows the engine to think the sensor is ok.
Fitted today and all is well.......

Happy days

The saga continues.......any help appreciated.
After being refunded for previous belt I've bought a kevlar malossi belt and Athena rollers.
Went to fit today and have the same problem. I now know that the belt is not being nipped between front pulley and it is tightened to torque spec.
It is definitely the correct belt for the bike.

The problem is getting the bike to rev above 2k while stationary before pulling away.
Once I've pulled away it very slowly picks up speed and then once above about 15-20mph pulls away and behaves normally.

I got back from the test run and just to check replaced the original belt again. This time it too wouldn't pull away as it should so it suggest something is wrong with the clutch or clutch pads?
The bell housing was very hot after the test runs!

Anyone got any ideas?