Guide for reinstalling the ACVs - Honda CX500, GL500, CX650, GL650

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Reinstalling the air cut off valves (ACVs) is an important part of reassembling your Honda CX500, GL500, CX650 or GL650's carburetors! We are working with a new kit today:

Here's how to install or reinstall the ACV - air cut off valve - on the Keihin carburetors on a Honda CX500, GL500, CX650, GL650 and other motorcycles.

Keep in mind that there are at least three variants of air cut off valve across the Honda CX and GL range - make sure you have the correct one for your year and model! I'll update this article with info on which belongs to which when I find it.

Make sure that where the valve sits is clean and free from any debris or old sealant etc. - there shouldn't be any sealant there but we see a fair few carbs that have had some applied in an attempt to fix a broken ACV. The little O-ring goes bevel side in to the carb:

Install the valve:

Next comes the spring. Now, the spring that came with the kit didn't quite fit so we re-used the original:

Now grab the cover and two bolts. Press the cover on, making sure that the spring seats properly - straight on - and install the bolts. They are JIS (what's that?) and take a JIS size P1 bit (eBay US, eBay CA, eBay UK, eBay AU).

Now do the same for the other carburetor. Once you are done there head back to the main carb cleaning page for the next step in the reinstallation process.