what are the two hoses on a atv carburetor

The hose on the bottom of the float bowl is definitely the drain. You use it to empty the bowl for storage or cleaning. The side port hose is usually a vent or overflow. Make sure the vent hose is routed up high to prevent water from getting in during deep crossings.

I've seen people mix those up. The drain hose should have a screw or valve on the carb body to open it. The vent hose just hangs loose but needs to be clear of debris. If you route the vent too low, mud can clog it and cause flooding.

On my Suzuki, the vent hose connects to a T-fitting that goes to the airbox. Check your service manual because some ATVs use the vent for emissions or crankcase pressure. Don't just assume both are drains.

I always zip-tie the vent hose to the frame above the carb. Keeps it out of the mud. The drain hose I just let hang below the engine for easy access. Never had an issue with that setup.

Actually, some carbs have a third hose for a vacuum line. If you see a small hose going to the intake manifold, that's for the fuel pump or petcock. Don't confuse that with the vent or drain.

I learned the hard way when I blocked the vent hose thinking it was extra. Bike ran rich and stalled. Unblocked it and it ran fine. So definitely keep that vent open and routed properly.

If you're riding in water, extend the vent hose up under the seat. I use a longer piece of fuel line and run it along the frame. Prevents water from getting sucked into the carb.

The drain hose is handy for checking for water in the fuel. Just open the screw and let a little gas out into a cup. If you see water, you know to drain the whole system.

On my Polaris, the vent hose has a one-way valve at the end. Keeps fuel from sloshing out on rough trails. Check if yours has that, because replacing it with a plain hose can cause leaks.

I disagree with routing the vent too high. If it's above the fuel level in the tank, you can get a siphon effect and fuel will leak out. Keep it at or below the carb height.

Both hoses are important for proper carb function. The drain lets you service the float bowl, and the vent equalizes pressure. If either is clogged or misrouted, you'll have running issues.

I just replaced my carb and the new one came with a longer vent hose. I routed it along the frame rail and zip-tied it. No problems so far. Just make sure it doesn't kink.

For storage, I always drain the bowl using that bottom hose. Then I disconnect the vent hose and blow it out with compressed air. Keeps the carb clean for next season.

If you're unsure, take a picture before you remove anything. I've seen guys mix up the hoses and then wonder why the bike won't start. Label them with tape if you have to.

The vent hose can also act as an overflow if the float needle sticks. So if you see fuel dripping from that hose, you know the carb needs a rebuild. Don't ignore it.

I run my vent hose into a small fuel filter to keep dirt out. Works great for dusty trails. Just make sure the filter doesn't restrict airflow too much.

On older ATVs, the drain hose might have a brass fitting that can break off. Be gentle when removing it. I snapped one and had to buy a whole new float bowl.

I've seen people use the drain hose to add fuel additives directly into the bowl. Not a bad trick if you need to stabilize fuel for winter storage.

Check your carb model online. Some have a separate overflow hose that looks like a vent but is actually for excess fuel. The service manual will show the exact routing.

Before you buy any replacement hoses, confirm the inner diameter. Standard is usually 1/4 inch, but some ATVs use metric sizes. A wrong size can cause leaks or poor fit.