I switched over my 16.5 Hp riding mower (2004 B&S Motor) from conventional oil (10W30) to synthetic (Pennzoil 10W30) this year. I noticed that it started burning about 1 oz of oil per hour this year (it never did before with the conventional 10W30). Some people have told me this is normal when one switches to synthetic and that it should stop burning oil in time. After about 20 hrs use, it is still burning oil.
This weekend I took out the spark plug (it was put in new at the beginning of this season) and it was all crudded up with dry black gunk on the electrodes and insulator material and in between the insulator and the round electrode that surrounds it. This material is dry and one can sort of chip it off if pressure is applied. The plug I took out from the year before was fine, a nice tan color electrode and fairly white insulator.
My question is whether the burning of oil would do this to a spark plug or would I have perhaps another condition that I should look into? Apart from gunking up my spark plug the mower seems to run fine and has 105psi of compression.
This weekend I took out the spark plug (it was put in new at the beginning of this season) and it was all crudded up with dry black gunk on the electrodes and insulator material and in between the insulator and the round electrode that surrounds it. This material is dry and one can sort of chip it off if pressure is applied. The plug I took out from the year before was fine, a nice tan color electrode and fairly white insulator.
My question is whether the burning of oil would do this to a spark plug or would I have perhaps another condition that I should look into? Apart from gunking up my spark plug the mower seems to run fine and has 105psi of compression.