1968 340 AVS 4425S carb problems

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Also if we have to remove the plugs how would we go about doing so with a drill or with flame?
 
We got the plugs out with improvement to performance under load. Some times when it get hot the idle starts to act as blower surge like the idle in this video but of course not as aggressive.


We have no idea why it would be doing this. The plugs appear to be burning pretty good (pics will be posted soon).
We are trying things little by little, each time it gets better but it is still not there.
 
Bugman said:
Another picture see mobile uploads [SOLD] - '70 carter avs carb #4425S idle holes open
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image_zpsek1s4zdmavs holes.jpeg
 
We did unplug the holes on the bottom of the carb but still at times it idles when in gear close to what blower surge sounds like but not as aggressive (motor was rebuilt to stock specs).
 
This is what the cylinder #4 spark plug looked like when we pulled it. We only checked one at random but we should check the rest of them to see how they look also.

30DBA85C-B199-4994-9199-0034E5E0A5EF.png


2619CC88-72E2-46A4-ABEB-5FE56149AED5.png
 
I was reading that thread, our car had similar problems like not a steady idle (only sometimes when it warms up then after moving it goes away most of the time), runs great at full throttle, and the plugs appear to be clean. We adjusted the screws similar to where he was when they figured out the problem, that helped ours but we are still running into the surge like state department above.
 
Thank you we will have to look for a exhaust gas analyzer to get the proper ratio. Would you have a recommendation on a good one? Also I am going to send you a dm to ask a question.
 
Joe1972dart said:
Thank you we will have to look for a exhaust gas analyzer to get the proper ratio. Would you have a recommendation on a good one? Also I am going to send you a dm to ask a question.
Click to expand...
The best tools for this is vacuum gauge and tachometer.
 
Thats the low speed jet or idle speed jet .033 changed later to .032. Carter instruction,s way back in the day were to use blunt end of sizing drill to check to see if holes were open.
 
That is first idle air bleed called By-pass .0492, right behind it is [ access threw by-pass hole] economizer also .0492 . The econ can be clogged up pretty easily.
 
That is the second idle air bleed or just plain idle bleed .040 that,s pretty small hole. Any dirt at all would make for rich idle. Now this is delicate work, fingers only just size checking and removing dirt. Not making holes bigger.
 
Sorry for the long delay for a response but life got in the way and we just got back to the car problem. As bugman pointed out the little holes on the barrels were clogged, thank you bugman. We also found out that the floats were uneven in height. The car is running a lot better with no more surge at idle. After unclogging the holes and adjusting the floats we put it back together and started to adjust. We set the air fuel mixture screws to the highest vacuum and then turned about 1/4 turn more to the richer side. We also found out that after unclogging the holes the air bleed started to work unlike prior when it did nothing. The car seems to preform better, start better, and definitely run smother.
Now to the new question, should we have went richer when we got the highest reading or should we have leaned it out or left it at the highest vacuum?

Again sorry for the long delay in response

Thank you

Joe
 
Joe1972dart said:
Sorry for the long delay for a response but life got in the way and we just got back to the car problem. As bugman pointed out the little holes on the barrels were clogged, thank you bugman. We also found out that the floats were uneven in height. The car is running a lot better with no more surge at idle. After unclogging the holes and adjusting the floats we put it back together and started to adjust. We set the air fuel mixture screws to the highest vacuum and then turned about 1/4 turn more to the richer side. We also found out that after unclogging the holes the air bleed started to work unlike prior when it did nothing. The car seems to preform better, start better, and definitely run smother.
Now to the new question, should we have went richer when we got the highest reading or should we have leaned it out or left it at the highest vacuum?

Again sorry for the long delay in response

Thank you

Joe
Click to expand...
 
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