MGB-GT vacuuming problem

[Sopwith_Camel]

well still have Vacum advance issues, I have put in a new 123Distributer which is great but the car is still bogging when I give it some "Welly"
could the problem be deeper then the distributer?
could it be the carb adjusters are to low to high?

at least it starts right up.

steve

 

[drooartz]

I admit that my first thought when reading your post title was that you had problems with your cleaning service... :grin:

I would probably go back and recheck everything. Check the float levels in your carbs, dashpot oil, and carb settings. Verify your timing and that your plug wires are good. Check valves and maybe do a compression test -- essentially try and rule out even the obvious things.

 

[Sopwith_Camel]

piffy titles get more eyeballs.
yeah I have had the carbs apart so that is my next suspect.
we had it running great but forgot to tighten the dizzy so it walked out of timing on the 12 speed bumps betteen town and the house,

 

[Sopwith_Camel]

still bubbly up hill. and i live on the top of the hill.
any ideas where a Vacuum leake might be? Ive been good but not perfect with the lead additive, could the issues be there?
steve

 

[Sopwith_Camel]

ahh the rubber O-rings on the Butterfly spinals were perished.
big improvement I guess i need to find one or two more leaks on the intake maifold.
steve

 

[drooartz]

Well found.

Eventually you'll have a fully restored car, one leak at a time. :grin:

 

[Gokart]

If those seals have perished I would suspect the spindles are worn as well (another vacuum leak). I could feel movement in the spindles by wiggling the end of the spindle with my fingers.

I see you said you had the carbs apart, what did you do when they were apart?

I would have thought you would have noticed the seals then, but then that might not have been what you were looking at I guess.

Anyway, I replaced the seals and spindles on mine (HIF's) and the butterflies as I wanted to get rid of the poppet valves before they too became a problem. I put new bushes in for the spindles and got a engine shop to ream the bushes and center the butterflies for me. Some do the reaming themselves ut I found it cost effective and reassuring to have a shop do them.

Of course I replaced the gaskets all round but missed replacing the o-ring on the cold start valve, which yours won't have as it should be an HS, which latter became a problem and I needed to pull the carbs off and replace it. My point is, while you are there replace every gasket and seal you possibly can to avoid having to repeat the process over and over.

Cheers Rob

 

[Sopwith_Camel]

thanks two year ago the choke O ring was leaking like a faust. so I did the adjusters the jets and the floats and the O rings.
this is my first carb Rebuild.
but it started to have problems when excelerating. I took a year off from driving due to cancer. this summer we put in a new electric Dizzy, plugs and wires. but the execration problem crept back in so I did the rubbers on the butterfly spindles yes one spindle looked worn.
yes we have done a compression test and its only a little out. yes we have sprayed start gass on the carbs while its running to find vacume leaks. not sure what to do next.