Plug and Tap

[Yellow 97]

I have at 97 Monster with 3500 miles on the clock. When i purchased it with 1400 miles on the clock i changed the oil, oil filter plugs etc. The front cylinder plug was encrusted with a hard deposit that resembles the head of a burnt match (white and black crust) this was hard to remove and also the curved end looked pitted.The bike was starting to run abit rough but changed the plugs balanced the carbs all went well until it started to run rough again abt 120 miles ago when i checked the plugs and again the front plug was encrusted again. the first set of plugs where NGK DPR 9EA's and i changed to the iridium version. The rear cylinder plugs are fine good colour no problems......i also have a tapping noise which isn't the usual tapped noise it's quite load and seems to be getting louder this noise only decreases very slightly when the engines hot...has anyone else experienced these probs or can tell me what they might be or if they are related i'd be very grateful.

Dave

[Pedro]

Sounds like the mixture may be out on the front cylinder. The tapping noise could be pinking which may also explain the dodgy front plug.

Be worth having it tuned up.

Hope this helps

Ped

[Yellow 97]

Well i've had a Mechanic look at the plug and he reckons it's burning oil without a doubt and the noise is def piston slap, the noise happens at all throttle levels so i don't reckon it's pinking and the plug can get the crusty deposits on it after a 100 mile blast...So i'm gonna get a new piston and barrel is there anyone that has heard of such a problem on a 97 600 monster or any other for that matter that can say for sure its ignition timing or fuel mixture.