Plugs are fouling.....

[daveh]

Had my Mistress in for new boots and a minor service this week.
She has done 120,000 ks, 103,000 of those are mine and are gentle ones, I'm a cruiser not a racer type.
So Robbie, my mechanic has been doing the work for most of the time I've owned the bike says the plugs have been fouling, and have needed to be changed the last three services, which I have done every 5000ks.
All of the diagnostics come back ok, he thinks the engines "vacuums" may be the issue, that basically she is getting old.
I've a scottoiler fitted and as I said I'm pretty gentle, could either of these be contributing to this?
He also warns me the gearbox is starting to be noisy.
Any ideas from those of a more mechanical aptitude?

[seth]

not sure what you mean by vacuums
but I'd check the rubbers between the air box and throttle bodies and throttle bodies and cylinder head by spraying wd40 on them when the bike is running you'll head the engine note change if they are drawing any air if they are you'll need to replace them also if they look cracked they are past it.
you can shorten the small vacuum pipe on top of the throttle bodies by a few millimeters if they look worn or damaged as there is enough extra on the hoses.
then see if that helps .

[Hooli]

120ks is barely run in for these lumps, it wont be worn out unless it's never had an oil change.

Have you still got the PAIRs fitted? that can cause poor cylinder scavenging by disrupting airflow in the exhaust ports. That'd make it run rich as it's not getting enough fresh air in to burn the injected petrol.

[daveh]

I'll mention these to Robbie.
Thanks blokes.

[RickC]

I had a problem with my plugs fouling, the mechanic was putting slightly cooler ones in went back to standard with no problems since.

[Veemanzero]

Check your breather system first. Are the plugs wet?. Or carbed up. Engine smoking ,if so what colour. Unlikely to be vacuum lines, it would be lean and burn the plugs. More info please