Just got back from the centre of town - have racked up all of about 30 miles since putting the bike back together - there is what I think is a new knocking noise coming from the rear of the engine.
Can't think how it could be related to the gearbox/clutch as it is present in neutral and in gear with the clutch in or out.
Could it be the replacement cat I put on (ie nothing to worry about) although it didn't rattle when I carted it around off the bike....
or worse some lump of rotating/reciprocating bit of engine bouncing off another bit
Will go and check again in a few mins once the oil level has settled so I can see if there is any in it
After 2 hours of browsing - called Steve at SED and he correctly diagnosed it as a worn LH throttle body. If I put my hand on the throttle cam noise stops. Apparently common (& harmless) problem which can be 'improved' by balancing the throttles.
Doesn't seem to be cat - is loudest on LHS around the starter motor???
Knock rises with rpm although it gets lost with other engine noise as revs increase. Its very clear on tickover.
Ade:!:
There is an aperture there where the starter motor fits in - that's why it may be loudest there I would guess. You know how little there is in there - just the clutch plate assembly. We torqued up all the bolts in there according to the manual didn't we, and I presume the clutch is not showing any sign of slipping? The only thing you could do quickly is to take the starter motor off, get a torch and shine it in the hole while spinning the back wheel. See if any of the bolts have loosened - just get the m5 hex socket on them through the hole like we did to align the clutch plate.
Can't immediately think of anything else - you could try jacking the back of the engine up to get teh back wheel off the ground, then spin the rear wheel with the engine off and see if it's the gearbox making the noise - try it in neutral with the clutch pulled in to minimise the friction.
Ade B wrote:After 2 hours of browsing - called Steve at SED and he correctly diagnosed it as a worn LH throttle body. If I put my hand on the throttle cam noise stops. Apparently common (& harmless) problem which can be 'improved' by balancing the throttles.
Top bloke.
Ade
PS. Anyone in the 'hood got a twinmax?
I've got one! I replaced my LH throttle body cos I couldn't stop it rattling. It was like that for a looooooooong time.
Cheers for the replies - Jason aren't you on holiday??
Definately the throttle body - Steve diagnosed it immediately and as soon as you push on the throttle cable cam (the bit that the throttle cable connects to to open the throttle) it stops.
Apparently there is a brass on brass component which wears allowing the throttle valve to open a teeny bit on every engine cycle - which makes the knocking noise.
No noise when starting from cold and its independant of clutch/gearbox which means I'm pretty sure its not related directly to anything we did...
Hi Archie, will happily take up your offer - where is 'just off my head'?
