I Hear Some Slight Knocking in My Engine

The four stroke engines that power today's scooters sold through Killer Motorsports are engineered to run smooth, efficient and most importantly – without knocking. Anytime you hear a knocking or ticking sound coming from an internal combustion engine, it's typically not a good thing. The cause of the ticking or knocking sound can be minor or the sign of a major mechanical issue; that could lead to complete engine failure. Never the less, a slight knocking sound is typically due to a lubrication situation. As such, here are a few tips for diagnosing this problem.

  1. Check your oil level: When you hear a slight knock or repeated tick every time the engine rotates, it's commonly due to low oil levels or old oil that is not properly lubricating the engine components inside the cylinder head. The first thing you should do is to check your oil level if you've recently changed oil. If it is low, add oil slowly and in small increments until the oil level is full. Start the engine and see if the tick goes away.

  2. Change the Oil: If you've check the oil level and added some and the tick or knock is still occurring, you need to change the oil and add new 10W40 conventional oil. Add the recommended level of engine oil, check the level to ensure it is full, and again, try to start the engine to see if the knock goes away. If the knocking still exists, the problem is internal with the engine and should be fixed as soon as possible before operating the scooter further.

  3. Verify your gasoline usage: Sometimes scooter owners will use lower grade unleaded gasoline in their scooters. However, we strongly recommend using premium unleaded gasoline, as lower grades have less octane which can produce higher levels of carbon and poor engine efficiency. The knocking could be caused by this factor. If this is the situation, empty your fuel tank, fill up with premium unleaded gasoline and run the scooter for a while to see if the knock goes away.

If you've completed the above steps and still notice the knocking sound, or if the knocking sound gets louder and more pronounced, it's possible that you have loose valves or something wrong with the internal engine components. Call our technicians at Killer Motorsports for recommendations as to how to address this situation, but make sure to stop driving or operating your scooter to prevent additional damage.


6509 Stephenson Levy Road
Fort Worth TX, 76140