HIF- 4 flooding

I have a nice stream of gas coming out of my front jet. About 6 to 8 inches high. I've rebuilt the SU's. Got new needles and seats. replaced the jets, checked the float for leaks, set the height of the float, checked for sticking on the float spindle, made sure all fiber washers were in place, took a reading on my old fuel pump and came out with a 4 to 4 1/2 pound pressure. I then replaced the fuel pump with a SU solid state fuel pump from Moss Motor. And I still have a stream shooting out of my front jet. No I do not have any lines hooked up wrong. All vent holes and passageways have been cleaned out. There are no vacuum leaks. I then changed the height of the float by dropping it deeper in the float bowl. This is the only way I can get it to stop. Yet I can not set the float to allow the gas to be just below the jet. I can't believe it is a faulty new fuel pump. And the carb has no dirt or rust in it. (I cleaned out and sealed my gas tank last summer) Gas lines are clear also. This is driving me around the bend. Maybe some fresh ideas will help

John,

Can you take a pic of the front carb sitting upside down, and with the bottom cover removed?

your float may have broken off the two little rivets that hold the float together, its very common, that or you have some dirt stuck in the needle and seat, I have also seen the pin that holds the float fall out

over flow vents may be plugged or maybe you have fuel goin in wrong place

Carbs overflow
overflows have really only one cause. There is more fuel in the bowl than it can handle.

There are several things that can cause this. while you seem to have checked them all, perhaps reviewing each in order might help.

1) fuel pressure too great so the shut off valve cannot stem the flow. Not common when using the correct SU pump, happens often is using an aftermarket pump with higher than necessary pressure.

2) shut off valve is faulty/dirty. Common. The grosse jet type of needle/seat is often found to be a problem these days. most recommend the neoprene tipped set.

3) float level is incorrect--set too low so it is not activating the shut off when it should. (this can be caused by a leaking float or by maladjustment). Common. various float problems can also affect this.(broken rivet, as noted, etc)

4) there's probably another one I just can't think of right now<G> Common (the can't think of it part<G>)

resolution: reset the float height and possibly replace the needle and seat. setting the float height on an HS4 is not shown in any of the books they all show a bendable brass tang. I get some small nylon washers with a hole just right for the threaded part of the seat. They are about 1/32"--32 thou--thick. I put one under each seat and snug up the seat (usually an 11/32 deep socket, some a 5/16" deep socket). this will compress the nylon a little, so don't crank em on hard. nice and snug without a ratchet...the same on each.

Then you will need to reset the mixture and retune the carbs.