Sputtering/backfiring around left-hand turns

[wkilleffer]

Hello everyont,

In the last three weeks, I've noticed that my 1974 MGB with HS4 carbs sputters and backfires around sharp left hand turns. While the problem seems more pronounced when the engine is still warming up, having the engine at normal operating temperature is no guarantee that it won't happen. What gets me is that it doesn't do this in right-hand turns.

I've done a pretty good amount of work on the carbs to get them properly balanced and adjusted, and have filled the dashpots. They don't stay full for more than a week, but even when they're perfectly topped off, the car will still do this.

It may be time to replace the floats in the float bowls, but this seems like a starvation situation rather than getting too much fuel. Any advice would be appreciated.

Thank you,

 

[dklawson]

Minis with twin carbs sometimes have this problem when pushed hard into corners. The common wisdom with the smaller HS2 carbs is to rotate the lids of the float bowls to change the direction the float swings. While the float bowl lids are off it's always a good idea to check the level of the fuel in the bowls and adjust the float valves as necessary.

 

[wkilleffer]

I'm willing to try it if you think it's workable. In theory anyway, looks like a few longer pieces of fuel hose might do the trick. Funny how little things like that can sometimes make a big difference.
Thank you,

 

[David_DuBois]

I've not tried this, but have read that there is a free sitting float and float arm (similiar to the ones in the T series cars) that Joe Curto, https://www.joecurto.com/ has available that eliminates this problem. Esentially it does the same thing as rotating the cap, but doesn't involve re-orienting the fuel lines.
Cheers,

 

[Bruce74B]

I have another possible solution...just turn right and go the long way /ubbthreads/images/graemlins/driving.gif

Seriously, it sounds like a typical HS4 float flooding and the above kit from Joe sounds most feasible.

Bruce /ubbthreads/images/graemlins/cheers.gif