Hello ,
I'll try to be precise .
2005 gs500f , very well maintained by me. 12000 miles .
Carbs in balance runs well pulls well .
Completely standard .
When started cold no noises starts 1st time every time .
Occasionally after being run and warmed up 20/50 miles and stopped for a bit when restarted i have a knock seems to be lhs of engine a couple of blips on the throttle and it goes away , doesn't happen all the time just now and then 
Any ideas , thoughts guidance welcome .
Many thanks in advance 
Mr g

Quote from: Mrg on September 12, 2024, 02:14:37 PM... knock seems to be lhs of engine ...

What did you mean by that ?
Sounds like it could be oil pressure related, revs go up and oil pressure increases. Is the bike on the sidestand when this happens ?
What sort of oil is in the bike, how old is it and what is the level like ?
Next time it happens check to see if the oil pressure warning light is still on.

Hope that helps.

Appears more prominent on the lhs.
No oil light on when it happens .
Happens on full or side stand .
10/40 motul oil in for 2000ish miles level correct .
All very odd as it doesn't always happen .
Thanks for the tips .

Could be your starter clutch is beginning to give up the ghost. Normally it's noisy on startup though, it's down on the LH side. Keep your ear on it.

Sure it's not the famous "cam walking" noise?

This is probably the infamous "cam-walk" noise, common on the 2004/5 bikes and remedied in 2006+ bikes with a redesigned cam.

To diagnose: warm bike until the knock occurs. Lean the bike (while idling) to the left--if the noise gets quieter or disappears, it's the cam-walk.

I had this problem and was able to source 2006+ replacement cams; but if that is not possible for you then don't worry about it, because according to Suzuki, the knock will not damage anything.

is the noise coming when accelerating abruptlyon neutral , from idle at low rpms with hot oil?