Hi Guys

I have noticed few times between last few months i had carburetor overflow problem and that time car was smelling fuel and was difficult to start it ?and after keeping it sometimes i could start it and drive and go as usual whAt causes this ? ideas please ?

thanks
regards
sumith

If it's overflowing then it would be the needle and seat or fuel float.

Yep. Needle and seat, or you are running an electric pump at excessive pressure.

Hi dattodude

I am running mechanical fuel pump ,it doesn't overflow everyday once in 2 weeks interval at one time

thanks
regards
sumith

In fuel injected cars the same problem occurs when the injectors leak.
When you remove your fuel cap does it hiss a lot?
Because you live in a hot place I'd check your float level and make sure your fuel tank breathers all work correctly.

That's a good point. On an emission controlled B310 like Sumith has, the fuel tank uses a sealed cap. It's only vented by the line coming forward to the engine compartment. Guys often block this line, not knowing what it is for. The line should be connected to the charcoal canister.

Does it run good all the time ?
If not, the B310 version of the "Charcoal Canister Purge Valve" may be bad, or some part of this system.

Debris in the float bowl can cause this, or as said before, float heavy from gas in-leakage.
Dunno if the 310 has a brass float like the 1200, most likely if so.
http://datsun1200.com/modules/mediawiki/?title=Float+repair

Remove the Charcoal thingy, if it's heavy, then further study on the service manual needs doing to see proper repair.

The early ones had a foam filter on the bottom of the ones I saw, dunno about your particular vehicle though.

I suggest checking the visible fuel filter for a dark line at the bottom that moves, that's water. Or some version of garbage that's not gasoline anyway.

Post updates to let us know what you found.