I know everyone says get the NAPA kit but hear me out. I bought the AAP kit made by GP Sorensen for $36 first. Nice looking kit with lots of little extras. However, following the 85 FSM I started tearing down the airhorn when I realized that the kit didn't have the diaphragm for the outer vent control valve. I returned the kit to AAP and went to NAPA. They had their NAPA brand kit for $53 and a LOT less parts. I looked at their kit and it didn't have the diaphragm either.

Confused I went back to my FSM and realized something. They don't show the Outer Vent control valve broken down. Why? The diaphragm certianly needs to be replaced with the others. Who has a kit WITH the diaphragm I'm looking for?

PS Both kits were verified by the carb numbers so I'm 100% sure they are the correct kits.

Well, two things come to mind.

I seem to recall my number matched NAPA kit did come with that gasket (not the diaphragm, just the gasket). However, in the few carbs I've rebuilt, that diaphragm has been OK, not to mention that's not a part they really expect you to disassemble (though I have to see how it works).

The other thing that comes to mind is my rebuilt carb came with a vacuum passage plugged in the OVCV so the darn thing didn't even work and it didn't affect anything about how the truck ran.

I'm really not sure what the heck the outer vent control valve does, but your carb 100% does not need it to run, so I would not worry about it. I've never seen a rebuild kit come with the diaphragm, but usually the gasket.

And yes, I have found that other kits come with more little things than the NAPA kit, but its usually useless stuff like new screws and extra clips. As long as its got 4 diaphragms, the main gaskets and jets (not as important), you're all set.

-Scerb

Niether did I until now. It's basically part of the ECS and purges the bowl of excess gas fumes when the truck is OFF. Even if this thing does work it won't matter with that 20y/o loaded up charcoal canister. <img src="/forums/images/graemlins/lol.gif" alt="" />

I'm going back to AAP to get their kit. It's almost $20 cheaper than NAPA's.

Thanks for the replies guys. <img src="/forums/images/graemlins/kewl.gif" alt="" />

http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6188811