ive got a KE20 and i have the exact same problem with leaking fuel. ive tried a new fuel cap which has slowed it down but it still leaks slowly, if i don't wash my car in a month you'll start to see the fuel building up on the side of my car. ive given up though now, i just fill my car 3/4 at most and make sure i wash my car once a month

can't remember when the pollution rules (1976????) kicked in but early ke3* shouldn't have them unless they have been retrofitted.

 

76 the emissions thingy came in I'm pretty sure.. 75 and below where PRE EPA...

 

I think, don't quote me on it lol :D

It's been a while, but in case anyone comes across a similar problem the solution was fairly simple.

 

The fuel cap I was using was vented but some how the one way action (only letting air in and not fuel out) of the vent had broken, so basically my fuel cap had a hole in it. I bought a new fuel cap that fitted, made sure it only let air in and no fuel out and it's hasn't been a problem since.