K5 400 drive belt replacement problem

[pikey]

I personally don't think he gave it long enough few hundred metres is nothing

[Data]

You may be right Pikey. But it shouldn't really slip for more than a few feet in my experience as it settles in to the pulleys properly. I've not had one slip more than that. However, I've not fitted a kevlar version so maybe it does need more settling in time but I shouldn't have thought so. I'm thinking the belt is either pinched in the variator and can't ride up giving the impression of slipping. Or, the variator nut is already coming loose.

[pikey]

He did say he'd ran it up to 5K revs on the stand with case off and it moved pulleys OK .

[Data]

Ah! missed that...

[Stibbs]

Right then, an update;

Stripped down again today and checked torques on both nuts (they hadn't come undone) & both were fine.
Reassembled ans took for spin, interesting⚠️
Pulling away is as if the belt is not engaging, it feels "lumpy" until I actually get about 10-15mph then it engages and it's fine.
Took it on the dual carriageway and it accelerates/decelerates fine between speeds 25-75mph.
It's just the pulling away that's problematic. Had another look at belt upon return and it seems fine, not slack, not too tight, nuts still tight.

I just wonder what the pulling away problem is now?

[Dave Weller]

You may need to do a few fast hill starts, this de-glazes the clutch drum and shoes. The whole set up requires regular use or you will get issues pulling away, the centrifugal clutch only works well when it is bedded in.

[Data]

Dave is right. This at the moment sounds more like a clutch issue than a belt problem. Did you clean out the clutch bell housing and deglaze the clutch shoes? If not that may be causing some judder as you move off. If you did deglaze the shoes it's imperative to keep the shoes flat and even all over the friction material surfaces. It's very easy to end up inadvertently sanding the shoes slightly unevenly if you don't use a sanding block. Also make sure to chamfer the leading and trailing edges of the shoes.

[Stibbs]

Thanks Dave & Data, very helpful advice.
I did blow out the housing and got rid of a lot of black dust. Being a novice at this could I have missed some? Or inadvertently blown some further in?
I didn't deglaze the shoes, I wouldn't know how. The idea of a sanding block sounds good. I'll need to look up the process and try that next.
Cheers

[michaelphillips]

Thanks Dave & Data, very helpful advice.
I did blow out the housing and got rid of a lot of black dust. Being a novice at this could I have missed some? Or inadvertently blown some further in?
I didn't deglaze the shoes, I wouldn't know how. The idea of a sanding block sounds good. I'll need to look up the process and try that next.
Cheers

you could try the 5 second hold of rear brake at 4000 rpm which works well i suppose (ON THE MAIN STAND)

[Stibbs]

Deglazed today but the same problem.
If I sit on the bike with brake engaged I cannot even get the revs up beyond 2k? Once I release the brake the bike moves forward, very slowly until I get to about 15mph then it starts to increase speed and beyond about 20mph or so is ok?
Very weird. I'm now contemplating taking it to the workshop down the road to see if he can sort it!!