know it applies to the spark plugs but can you tell if you’re running rich from carbon build up in the exhaust? took my baffle out yesterday and it was sooty black with a furry build up just inside the mouth of the can. really wanna avoid the cost of another dyno run if i can help it and it’s too rainy to tit around with me plugs today. it’s a carbed engine btw. any help much appreciated
When did you last clean/change the air filter?
got a k&n in there. was put in about 11 months ago and i’m assuming it was cleaned on the last service about 1000 miles/2 months ago but to be fair, i haven’t checked it… the build up looked like iron filings but sootyish black…
That does sound a bit excessive to have “Designer Stubble” in your can:w00t:
yeah right. hopefully having the baffle out will cure it but wondered if anything else could cause it, or if it’s fairly normal with a stage 1 dyno? to my mind it’d indicate overfueling but i know pretty much f all about these matters.
heard the performance can go a bit flat if running lean. is there anything else i can look out for aside from checking the plugs?
A K&N filter and a can would normally, if anything cause the bike to run lean, the opposite to what you describe.
What bike is it?
a 600 hornet. 2 years old. had it stage 1 dyno’d last year after adding the can and air filter. in the winter i noticed a small leak down at the link pipe collar (steam escaping on start up). wondering if this was there when they did the setting up as they say the fueling was spot on. i’ve since put silicone round and made sure it’s all sealed. so wondering if it’s been running rich since then. if the symptoms match what i’ve found it sounds about right but paranoid of seriously damaging the engine due to not enough fuel in the mixture…
Could be the case mate.
A rich running engine isn’t likely to damage itself, but a lean one would cause it to run hot and cause all kinds of pre-ignition and burnt valves.
Might be worth considering another set-up mate
yeah spose that’s the only way i’m gonna definitively know :unsure: looks like there’s no short cuts really. just can’t help thinking it must have been running rich to cause that kind of carbon build up.
cheers for your help fella. spose i’ll just ring round a few dyno places to get the cheapest quote. bikes eat money :crying:
Hello Mr A
I should not worry too much. As our Hornets always run a bit rich as standard. As long as the plugs are nice and brown and not really black things should be ok. What mileage you now getting before you go to reserve with the stage 1?. I used to get anything up to 125 with the standard set up now with the pilot screws opened up it’s about 118.
alreet fella!
commuting i get about 95/100 before reserve. out on the proper roads i get about the same as you. put the baffle back in now as i was getting far too much attention. anything above 5k and people looked horrified :hehe: plus the engine braking was almost none existent. don’t worry tho mate, i’ll make sure it’s out for our first run of the year 
i don’t know where you get your servicing done - but most places won’t clean a K&N filter - so probably not nice at the moment!
maybe i’ll have a look over the bank holiday weekend and make sure everything’s ship shape. cheers 