fzs600s unrideable under load

[unfazed]

Hi,

03 fzs600s now just over 100k, runs perfectly and revs crisply at a standstill, but under load has become unrideable. This problem was at about 7,000rpm, but has got worse, so now at lower rpm.

My dad thinks it could be the ecu generating a weak spark, any ideas?

Thanks,

Start with the easy/obvious bits first


Check/change the Air filter, fuel filter.
Check fuel tap flow
Check pump flow
See if anything changes

Drain float bowls to check for dirt and water in the float bowls
Drain tank  dry and refill with fresh fuel. See if anything changes

If problem still exist let us know as there are other simple things to check and rule out by trial and error.

It could even be something as simple as a dodgy regulator but rule oit the obvious ones first