Recently put headers on a 73 fj40. It is more difficult to start and requires pumping the gas several times. (like 10+) Before the header installation the manual chole worked fine. I got some starter fluid to assist and that worked well. I used a second time and it started right up but cut off after 100 yards and would not start again. Some times when cranking a heard a low end engine knock, similar to a stall. Never got it started up. Could I have flooded it? I did spray starter fluid in the carb several times, could that be too much?