Honda CX 500 Forum banner
1 - 4 of 4 Posts

· Registered
1 Posts
Discussion Starter · #1 ·
I just bought a 1979 CX500 and I have a few questions about the carburetors.

1. When syncing the carbs where do you start? Do you adjust the mixture screws first and then adjust the carb sync set screw?

2. How many turns out do you set the screws to? The previous owner new very little about carbs and messed with both of the screws so Im sure they are out of whack.

3. The fuel valve started leaking when I was cleaning out the gas tank. Is there anyway to take it apart and fix it? It seems like there is probably an o ring that is rotten and it could easily be fixed if I could take it apart.

4. And does anyone know what size adapters I need to check the vacuum pressure? Is it 5mm or 6mm?

Thank you!

· Super Moderator
2,549 Posts
After the engine warms up to normal operating temperature, set the idle speed at 1100 rpm and then set the balance between them. Then you can set the mixture screws. 2 1/2 turns out to start with.

The size for the vacuum ports in the manifolds is 5mm X 0.8mm thread pitch.

Try flushing out the petcock. Pull it out and spray electric spray in both directions. Turn it to on and reserve during the flush. Then blow it out with an air hose. There may just be debris that's lodged under the rubber letting the fuel leak past it.
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.