I bought an 84 1/2 ton a couple months ago. It has a 1bbl Holley 6184 feedback carb with lean burn. California rules state I have to run the lean burn regardless of whether or not it pollutes more or less than a non lean burn setup. So I am taking up the challenge to get this thing to pass. The guy I bought it from gave me a very vauge explanation. "The guy said it failed because it was getting too much air". Vacuum leak? Exhaust leak? I don't know, could be a combination of both.

First thing, I fixed the ignition wiring because it had to be started by a push button wired to the starter.

I checked the vacuum and it was reading about 15. I sprayed some soapy water on the intake and carb and blew some air up the pcv hose to check for leaks. Found bubbling around both carb hold down studs. Reseated both of them and my vacuum jumped to 18. I get a bit of a rev up when I shoot the end of the throttle shaft with carb cleaner but theres only one carb shop in my area that'll rebush this carb and they charge $110...so thats not happening. I'd rather see 20 on the vacuum but 18 will have to do for now.

I noticed a vacuum leak where the head pipe meets the manifold. I separated them and noticed there was no gasket in there. Put one in and it fixed it but possibly not all the way because I can still hear a ticking/rattle sound under the hood.

It was real hard to start and the choke wasn't closing when I hit the throttle so I took the choke coil off the exhaust and sprayed the coil with pb blaster. Reinstalled it and the choke slammed shut when I hit the throttle.

I also have a set of NGK UR4 plugs I'm going to install this week.

Now do you guys know any tricks to help with emissions? Is Sea Foam ok to run through the motor or can that affect the smog test? I want to at least pour a little down the carb to track down the exhaust leak(s) but if it's safe, I'd like to run the whole bottle through. I've never used it before so I'm not sure how it affects the catalytic converter and all that.

I'll update my results when I take it in. I have a temporary registration until June 20th so I gotta get it done by then.

Do the seafoam out in the open. Get the motor warmed up and pour a third to half the bottle slowly down the carb while motor is running (or use a vacumn source like power brake booster line). Shut the motor off and let sit for 5 minutes. Restart motor and let smoke clear. This way it won't affect emissions. If you pour into tank who knows.