SU carb float settings

[UKPhilTR7]

I will be changing my SU carb float needles soon and I was wondering if anyone here would be able to give me a bit of TR7 SU H6 carb float setting advice.

I am OK with changing the float needles (as that looks easy enough). I am just a little unsure as to how I would set the float needles, if they need to be done. I watched the Moss video and it said to use a drill bit to measure the cap when the foat was upside down.

Can anyone give me any advice on this process of setting them and what to use if I need to increase the gap?

[Cobber]

what to use if I need to increase the gap?

a thicker drill bit

[UKPhilTR7]

Lol did mean as in a a thin washer to ensure the float needle housing (Seat) sits a little higher. Thus forcing the float needle to sit a little higher and increase the gap.

[sonscar]

At the risk of being shot down in flames,just bolt them in and they will be near enough.Steve.

[saabfast]

I agree. When I had problems with one letting by and cleaning did not sort it I just replaced and put the new one straight in. No problem since.

[UKPhilTR7]

That is good news that people have just replaced them and not had to set the floats. I watched the Moss video and that said about adjusting the gap so that got me thinking. I could try fitting them and see how I get on and adjust the float level later if needed

[Hasbeen]

Phil there is no adjustment on the plastic floats. You can put a couple of extra washers, but no more under the seat, but this has so little effect it is hardly worth doing.

There is an aftermarket float available, with a bendable copper arm, which gives some adjustment, & is probably useful.

You can machine the washer between the float housing & the carb body to a wedge shape, to improve the angle of the float chamber. You will notice the front chamber is much higher in relationship to the carb throat, due to the front high angle of the motor installation. In the early 4 pot TR2 to TR4 engines the bowls were installed at an angle to the main body, that set the float housing horizontal when the engine was installed. Bean counters mean our cars didn't get this.

I set my carbs up this way, when I first had flooding problems, after fitting a new fuel pump. It helped. I also machined 2 tenths of an inch off the top of a float bowl, & fitted this to the front carb. lowering the bowl top, & thus the float level by this much. NONE OF THIS CURED MY FLOODING COMPLETELY.

I finally checked the fuel pressure, found it to be 4 PSI, brought it down to 2 PSI, with a spacer between the pump & block, & cured the problem.

Hasbeen

[UKPhilTR7]

Thanks Hasbeen, I have the thick spacer on the fuel pump but I think I may need to get the fuel pressure gaugue on it to check.

I have the new float needles now and I am in the process of putting them on. One thing though the front needle has a small brass washer on it, but the back one dos not. The washer is shown in the rimmer brother catalogue. I have not got a spare one that size so hopeful it will OK with one with the washer and one without.

[UKPhilTR7]

Today I put both the new float needles in and replaced the hard line from the pump to the carb metal line. In the end I did not have another small washer to put onthe float needle housing, so I put the front float needle on with the washer and the back one without. I thought at the end of the day it should not be any worse, I wanted to get beryl running again and I can replace it again at a later stage.

She started up nice and there wax no smell of fuel around number one carb while the car waz running or after. Most importantly there was no fuel leak either. It seems to of fixed the issue of the number one carb flooding, but yo time will tell. All looks good though so far.