Monarch Motor Bike Roughly What Would It Cost To Replace A Distributor Cap In A 1977 Mercury Monarch At A Shop?

Roughly what would it cost to replace a distributor cap in a 1977 Mercury Monarch at a shop? - monarch motor bike

My car, a moment off, if rurn the off-key. It is a noise that sounds rough and shakes the engine. While the car is working well. Sounds so bad, if I turn him out, because there are carbohydrates Fule. Is it time to adjust or CAP dealer. 1977 Mercury Monarch six straight. I do not know much about cars, but no information will be useful. Thank you!