Clunking And Stuttering

gazzatheyid · Dec 26, 2020

Hi guys,

This isn't about my Triumph but my BMW F800st

I'm not technical at all but weird one the bike is stuttering like the brake is being applied sporadically with a clunking type sound when on the road. Revs up and down no issues when standing and can wheel it back and forth freely in neutral no issue.

Would this be symptoms of potential drive belt belt failure?

Head scratching.

Edit: Had another mess with it appears the belt drive is slipping badly. Only had the thing 6 weeks. Annoying.

Cheers in advance for any help

Tigcraft · Dec 26, 2020

I’ve the same bike although it’s a gt @crispey he runs similar too. Is it from a dealer? If so ask for a belt as they are a lot of money for those and no aftermarket as I know of. Theses belts DO NOT SLIP. It’s like a cam Belt. They can be adjusted but with out exactly looking at mine in the cold garage I can’t tell you exactly how today

Ducatitotriumph · Dec 26, 2020

I had an xdiavel (ducati) with a belt and it HAD to be adjusted by the dealer (for free)
I didn’t need anything adjusting in 4k miles but thats their rules.
Apparently, (according to them) its got to be the correct tension and logged in the book as if it breaks, it's a a warranty claim.
That was ducati though so b@w might have a different policy.
It does sound like a front pulley prob/drive shaft issue?

gazzatheyid · Dec 26, 2020

Cheers guys, bought privately so no come back.

My mate looking at the back wheel said the belt was slipping? Wouldn't shift in first making a terrible noise, I had to put her to second gear and back as wouldn't move. Then moved forward again with more noise in first.

Was reluctant to buy BMW because of the reputation around faults. Hope I'm not proved right.

Tigcraft · Dec 26, 2020

As for reputation, these bike are generally bomb proof as the mileage speaks for itself usually. Mines coming up to 50,000 as it’s full Allan jefferies serviced from new with no expense spared. It rides very close to a new bike considering it’s a 2013. Early STs up to about 09 had a bit of piston slap when cold But still a good ride.
I think I’d take off the cover to inspect the front sprocket. The belt needs inspecting for teeth missing or frays. If anything like that then new Belt.

What years yours? Get some close up pics up

gazzatheyid · Dec 26, 2020

Tigcraft said: ↑

As for reputation, these bike are generally bomb proof as the mileage speaks for itself usually. Mines coming up to 50,000 as it’s full Allan jefferies serviced from new with no expense spared. It rides very close to a new bike considering it’s a 2013. Early STs up to about 09 had a bit of piston slap when cold But still a good ride.
I think I’d take off the cover to inspect the front sprocket. The belt needs inspecting for teeth missing or frays. If anything like that then new Belt.

What years yours? Get some close up pics up
Click to expand...

2012 model. Thanks for the reply will take a look tomorrow if my mate has any tools. Things never go wrong near home!