Video: Honda XR400R Carburetor Cleaning

Maybe you just bought a used XR and it just won’t start. Maybe your bike has been parked in the garage for a bit too long. Maybe you simply got some bad gas. No matter what the reason, there are a variety of conditions under which your XR400R’s carburetor may be in need of a deeeeeeep cleaning.

Well, never fear—Aloop’s tech department is here to walk you through the process. Disassembling your carburetor isn’t all that difficult; the trick is in knowing what to clean, what not to worry about, and how to put it all back together. For that reason, we’ve compiled this video, which outlines each and every phase of the carb cleaning project from start to finish.

A few important notes before you get started:

 Workspace

Make sure you’re doing this in a clean, uncluttered indoor workspace. The goal is to get the carb as clean as possible, and you can’t do that if you are outside in the wind or in your garage without the proper tools. Take some time to set up your space so that if you drop a small component, you’re not going to be searching on your hands and knees for the next half hour.

 Carburetor Cleaner

There’s some question as to whether contact cleaner is equal to carb cleaner or not. The truth? Carb cleaner is superior for this task, because it will dissolve gummy build-up better, and the cans are pressurized to a greater degree. Contact cleaner will work if it’s all you have, but just know that it’s not as good with gum as pure carb cleaner.

The Air-Cutoff Valve

Simply put, your XR400R’s air-cutoff valve is an anti-backfire device. It has zero effect on how the motorcycle runs, and it never needs to be tuned for altitude or jetting. As a result, it does not need to be disassembled or cleaned throughout this process. Leave it alone, and you’ll be fine!

 Inspect As You Go

As you work, inspect the condition of all components on your carburetor. If you run across something that is damaged (such as a fuel line), replace it! Also – and we say this in the video, but it bears repeating – don’t overtighten those jets! They are made of brass, can snap off super easily, and are a royal pain in the next to remove once broken.

Once the Carburetor Is Clean…

After you’re done detailing and reinstalling your carb, there are some things you can do to help keep it clean. Aside from the obvious tip of only putting clean, fresh fuel in your Honda’s tank, you’re also going to want to turn the fuel petcock to off anytime the bike is parked (such as at the end of a ride). Two other good rules of thumb are:

• Drain the carb if the bike is going to be parked longer than one month (you can easily drain the float via the 17mm float drain plug, or you can putt-putt around with the fuel petcock off until the float runs dry).
• Drain the tank if the bike is going to be parked longer than three months. You can do this by draining through the fuel line into a gas can, but if the tank is totally full, it can be faster to just remove the tank and pour it directly into your fuel can.

Good luck, enjoy the video, and be sure to contact us at www.aloop.com if you have additional questions!