1980 Datsun 720 L20B in California

[spacewieners]

Hello!

I just recently purchased a 1980 720 with 95k original miles and I'm tremendously excited about it. I'm 24 and have a fair amount of experience with cars with EFI, but this will be my first carbureted vehicle.

Anyways, everything seems to work fine until I have been driving it at relatively high RPMs (freeway, specifically) and then I let it idle again back on surface streets. While it doesn't die, it idles very rough and when I go to turn the engine off it seems to die relatively rough as well.

I have checked the plugs, vacuum lines, air filter, intake, fuel filter, as well as ran it with a tank of carburetor cleaner in it, and the issue still persists. It does have the original carburetor on it, and I was wondering if that may be the issue.

Also, if it is, I am in the market for a new carburetor and was wondering if anyone could recommend any manufactures that sell carburetors that meet the criteria for California CARB laws.

Any insight would be extremely helpful, and I apologize before hand if this issue has been discussed in previous threads as I am new to these forums.

Thanks!

[86 720]

Those old Hitachi carbs were crap. Always had issues with them.

You could get a rebuild kit, but I would recommend getting a new Weber carb. You'll notice a tremendous difference.

If you haven't already, buy a can of carb cleaner and go to town on the interior.

You also may want to check the timing too.

As and FYI, your L20B was used in a LOT of Datsuns, you can also look at 510s, 620s, for motor diagnosis too.