Another carb question, float level and how to adjust it

Started by Gaz_95L, June 27, 2013, 11:12:21 PM

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Gaz_95L

Hi,

Thanks for all the advice.

I took the carb off and dismantled it, but there isn't much oppotunity to add additional washers under the main carb body. Where the float chamber attaches to the main carb body there is a lip and if I add many more washers (maybe I could add one) then it would not fit over the lip and hence not attach properly.

Unfortuantely I don't have any spare washers that fit so I was forced to go the spacer route. I used the screw cap off a spark plug and cut it down to about 1/8" and added that between the float and circlip. I also thoroughly cleaned all the air / fuel ways in the carb (again).

When I refitted it and started the bike up it was better (although not perfect), but it still refuses to tick over. When the pilot screw is fully screwed in it actually stalls now so it must be working ! When I screw it out it eventually starts to run rich again, but no where inbetween will it tick over. The only way I can get it to tick over is on the throttle.

I guess the next step is to take it for a run and do a plug chop to see if its ok and normal running speeds.

Maybe at the end of the day the carb is just very old and a little worn out !

Thanks again.

Gary.

Gaz_95L

Hi,

Thanks for both replies. I must admit I didn't think about moving the actual float chamber itself up and down, I was thinking purely of adjusting the actual float inside. I'll see if I can do that and let you know.

With regard running rich, yes I think its running rich at all throttle openings... in fact it doesn't want to rev at all. It was running very rough and there was black smoke, the plug was pretty wet also when I took it out.

I know different parts of the carb (pilot, cut away, needle and main jet) work at different throttle openings... so maybe there all getting affected by the float height.

Petrol was dripping from the hole in the carb body, but this did stop when the bike was running (if you can call if running !). I can say that when the pilot was fully screwed in it did start to run better.

Regards,

Gary.

Graham9

Hi Gary,

I agree with Singleminded. Also, you can lower the whole float chamber by adding washers underneath the fixing to the main body.

These carburettors usually leak fuel out a small hole in the main body, especially when the engine isn't running, if the fuel level is too high. Is it running rich at all throttle settings?

Graham

singleminded

I can't help you with specific advice on a TT carb, But with a standard carb you can get different length bottom nuts for where the float chamber bolts on.Also you can adjust the fuel level in relation to the main jet by rotating the carb body so that the float chamber is higher or lower than the marked level on the side of most TT carbs.John

Gaz_95L

Hi,

More carb help I'm afraid.

Unfortunately since fitting a TT carb to my Sunbeam 95L it seems to be running very rich. It has been suggested that the float level may be to high (needle jet is set to the third ring from the top). I've noticed that the float needle on my TT carb only has one groove for the circlip meaning I can't adjust it, I therefore assume I need to place something between the circlip and float ?

I thought about using the screw cap off a spark plug and cutting it down to about 1/8" and using that, can anyone offer advice to whether this is a good idea or suggest something else I could use ?

Thanks,

Gary.