misfire

[del]

hi all
has everybody had the misfiring problem? there seem to be loads of threads about front cylinder not firing and missing,ive changed my plugs several times but after a day or two its back to missing again??? whilst at work today i got another spark plug and put it in the cap whilst leaving the origonal plug still in the head,as i put the plug that was in the cap near the top of the plug that was still in the head it sparked but not impressively....but when i put the plug near one of the allen boltson the cam cover the spark was brilliant???
i have now put a piece of wire around the washer at the top of the spark between the washer and the the plug ,and around the allen bolt in the cam cover and it now runs superb??? so is there an earthing problem with the plugs that causes the missing problems???????????????????????:confused: :confused: :confused: :confused: :confused: :confused: :confused: :confused:

[Scotty]

sounds like it

[del]

:banghead: someone else please reply!!!!!!!!!!!! does this seem right or not cause im very confused about this, it seems too easy to a very strange problem! :banghead: :dunce: :hissy: :confused:

[randv69]

Um, nope it doesn't seem right! As Scotty confimed you pretty much have described a poor earth and devised a good solution in my book! (must tell the ratbikers about that one).

If you want to prove beyond doubt get a multimeter reading resistance and take a reading from your battery earth terminal to the allen bolt that works well. You should pretty much get short circuit - an ohm or two at the very most. The take a reading from battery earth to your front spark plug port. It will probably be reading a lot higher, maybe 10 ohms or more. Using a bit of copper grease on bolts might make a difference, but I am not great at the mech bit - perhaps scotty might know what bolts might be critical in this case.

If you do not get much of a difference between the two readings taken, it may be that your wire bridge has taken out the bit of difference that was critical to running like a sack of cack to purring like a kitten. In this case it may be your HT lead on the way out. As a guide you should get around 20K from positive input of coil to the bit inside the cap that mates with the top of the plug. (step by step - coil is 15K, lead is an ohm or two and cap is 5K between HT lead input and plug cap bit.) If you get 20K, I would leave this bit well alone and concentrate on improving the bonding of the casing.

Hope this helps.

[del]

thanks that helps a lot..notbeing technically minded ill get a friend to do the checks that you suggested and let you know the outcome:mand: ..

[del]

tested bike today.....misfired for first ten minutes,kept it on full throttle and it eventuallycleared then ran and ticked over perfect?????? no idea but i suppose it is a ducati after all! :chuckle: :chuckle: :chuckle:

[NewMon]

They are made of cheese. But with passion! Bellissimo

[del]

started again today ..all ok ??... have come to conclusion that the carbs need cleaning out?anyone agree??