Super Hydrocarbons

89 ram 50 NA with this Mikuni in CA, refuses to to pass smog...

Feel like I've tried everything and yet still I think the problem is a simple fix. Two years ago I passed smog and I dont think anything has changed on my carb so here goes..

Basically it runs super rich even though it doesnt seem to use much gas, it smells like unburnt fuel at the tail pipe. I wonder if my timing might be off, could that cause this?

Otherwise its all carb, I know my thermo valve on the intake isnt working because the nipples are broken, enough to cause a leak to pretry much the whole system. But this I dont think is enough to cause this much excess HC. I'm hitting three times the limit on exhaust test. Also, on Ca Mikuni's the mix control screw is epoxied over or something because it aint there I looked. Anyways I really need some help on this because I'm months overdue on my smog and I dont want to get towed. Any help or brainstorming would be appreciated, and I know this is a common problem because I've seen a couple good looking d50's at the junk yard now that the guys there say probably just didnt pass smog so this might help someone else in the same situation.

Thanks,
Indigo

Sounds like the carb needs rebuilt. There are gaskets inside the carb that fail and allow fuel to dump into the intake due to the corrosiveness of the ethanol fuel. A bad float that sinks could also cause this problem. Check your egr and sub egr for carbon buildup, and replace the PCV valve.