Plug colours.. Tuning required?

[darren_soh86]

i juz replaced my plugs on sun.. and these are the colours of the plugs i replaced...

 

These are NGK CR9EH-9. I replaced them with Denso U24FER9 with is equivalent of NGK CR8EH-9 which are stock.

 

the uber black one is the cylinder that remains only warm in after i start the bike.. the other 3 cylinders get pretty hot to touch.. the bike stutters on acceleration sumtimes too.. i tink that cylinder is running too rich..

 

shd i get the carbs serviced and balanced again? i dunwan the new plugs getting fouled again..

 

Appreciate any pro-sters opinions..

http://img179.imageshack.us/img179/9534/dscf0476hc1.th.jpg

[newcomer]

not a proster here but my take is no.1 and 2 of your cylinders are running rich, oil fouling the plugs. no. 3 is ideal but no.4 is slightly rich.

how many mileage your plugs? do the black ones look shiny? there is rust on the washer of no. 4, check your HT leads. i noticed no. 4 thread also looked blackened.

u should tell us more abt ur bike condition?

[darren_soh86]

i dunno the mileage on the plugs.. juz got the bike and 1st plug change.. the oily part.. i dun see oil on the electrode tip but there are oil on the threads on every plug esp the very black one..

 

the previous owner claim to have done an overhaul 20,000KM ago.. n has provided me with the receipt to prove it.. Apr08.

 

the plug cable looks ok upon inspection..

 

prior to changing the plugs.. most of the time when i start the bike.. the bike is weak feeling like 1 cylinder is not firing.. the cylinder exhaust header will feel alot cooler than the rest.. after riding for a while, it sumtimes rcv power but will stutter at times.. so i replaced the plugs.. yest was good.. but today coming hm from sch juz nw.. i got the stuttering again.. but it went away with warmer engine after riding..

[newcomer]

you just bought the bike from the previous owner? if so has the bike been sitting for sometime? most of time when a bike is stored for a long time bad things happen to alot of things. one of the common things is your carbs clogging. bring it to your mech they know what to do.

 

i would advice you not balance and tune the carbs first before checking your compression value. if your compression is low or not within oem specified range of each other nothing you do to the carbs will improve your ride.

[JbAtRaCeR]

Bro,might want to check you airfilter also. Maybe too dirty. For me no 1 and 4 the insulator colour is good,no 3 is best. No 2 is overich or oil fouled.

 

Best way to check the plugs is to run at the desired rpm(throttle position) for a few kilometers and shut off the engine,clutch in and coast to side of the road. Then pull out the plugs and read it. Its a very troublesome process.

 

http://www.dansmc.com/sparkplugs1.htm