Spark plug fouling on the Duc

[DucBloke]

I just had a big bore kit put in 400 miles ago with higher compression pistons. The mechanic told me that it was only running a little rich, but I fear it is much richer than acceptable. The front cylinder started to cut out after only 200 miles. The plugs were a little old, so I changed them out. After only 200 more miles I found that the front plug has fouled again badly and I lost the cylinder on my way back home, in the rain I might add. Made for a nasty trip.

Both of the front plugs are very black, were wet with oil/fuel and crusty. The back cylinder plugs actually look pretty good.

Will anyone confirm that this is a sign of the front carb running richer than the back? I have pictures of the plugs if you care to see.

[Anonymous]

I would think if you have oil on the plug you have other issues to deal with, namely why the oil is getting on there to begin with!

[DucBloke]

A little oil on the threads is normal for Ducati's, especially on the vertical cylinder.

I went ahead and pulled the carbs off for a rejet. Stage II is in and I'm now playing with the mixture. The plugs are almost the same now, with a normal slightly cooked look, rather than completely black.

Just goes to show, if you really want something done right, do it yourself. Taking your bike to a racer/mechanic means your street bike just doesn't get the attention that it should (especially in the weeks before the first MRA race).

[rocktboy]

well if you paid good money for your service take it back to the mechanic and show the fouled plugs in his/her face.... as simple as that....

[DucBloke]

complicated, but my business will be going elsewhere from now on. He really messed my bike up.[/u]