Motorcycle restoration


Hello. I have a 1971 Honda SL 175 two cylinder, four stroke, overhead valves.

I disassembled the thing this past weekend for a frame up restoration.

There is an oily deposit on plugs and on exhaust ports and inside exhaust pipes where they connect to the head.

The bike sat in shed for 30 years (!)

But it ran this past July (w/new battery, new condenser, new points and plugs, and a carb clean), albeit with a pretty rough rough idle.

Diagnosis 1: burned/bad exhaust valves/ valve guides

Diagnosis 2: bad rings

Any thoughts or other possibilities?