My Unit Bogs at Higher Speeds

A “bog” when under-accelerating is a problem that occurs with many ATV owners; however, it's not always caused by a major mechanical failure. A bog or the lowering of the RPM band under acceleration is typically caused by an obstruction of fuel or air into the combustion chamber. This area has air or fuel lines that are blocked by debris of some type. If you have been doing a lot of mud or loose sand riding, it's more likely the air filter is dirty and simply needs to be cleaned. However, if you've been casual with your ATV riding, on street or dirt, it's most likely going to be a problem with the fuel system. Here are a few things you can do to diagnose and fix a bogging problem that is related to the fuel system.

1. Inspect the fuel line that runs from the gas tank to the fuel pump. You'll want to make sure that there is nothing in the fuel line or that there are no pinches in the line that might cause fuel flow restriction. If you notice any obstructions, or objects in the fuel line, remove the fuel line and clean. Reattach the fuel line and test the solution.
2. Inspect the fuel line from the fuel pump to the engine. Once you've checked the first fuel line connections from the tank to the pump, you'll then want to test the connection from the pump to the engine. Remove the fuel line from the engine (either the fuel injector or carb) and place the fuel hose in a clear bottle so you can see the flow of fuel. Turn the key to the on position and press the start button. This will activate the fuel pump. If the volume of fuel is consistent and flowing at a solid rate, the pump is good. If there is very little fuel coming out, the problem is most likely a faulty fuel pump or clogged fuel filter and should be replaced.