I bought an old Masport tiller with 3.5 hp B&S that hadn't been used for several years. After an oil change, new spark plug and air filter (and a new pull start rope to replace a broken one) I can't start the engine when cold. Aerostart does the trick to start it, and it then keeps running though it seems not as smoothly as it should; after it warms up for 5 minutes or so it starts well. The new spark plug got sooty very quickly.
There seems to be a fair bit of carbon on top of the piston (looking through the spark plug hole), but it doesn't blow any visible smoke. Compression doesn't feel great but I think it is acceptable; I don't have the means to measure it. I just want to till compost into the soil a couple of times all over the 1/4 acre block in preparation for landscaping before disposing of the tiller.
I suspect worn piston rings and am thinking of using some heavier oil I have at hand to get by for my needs without further expense.
Any comments, tips or advice would be greatly appreciated.
