440 6 pack running rough

[boss429kiwi]

Hi

My 440 6 pack "stumbles" below 2500 rpm. It revs out very strong above 2500 rpm.

I had the carbs rebuild 6 months ago for this same reason. I have removed the needles and cleaned and reset the float levels, with no improvement. It also seems to be running slightly rich.

It seems like a fuel issue? I will add that at times it seems to go away? And runs fine down low???

I run it on 50/50 pump gas and AV gas.

Thoughts

Cheers
Gary

[b5blue]

Ignition? Are you using vacuum advance? (Mine LOVED it when I got it working.) Lube inside the dist. if a Mopar Dizzy, pull the rotor off and lube the wick in the shaft. Check grounds and connectors to ignition. The reason I say all this is the problem is intermittent. 

[Cooter]

Need more info...Question/Problem has one symptom and about 15 Causes.

1. Engine ok? Rebuilt?
2. Who "rebuilt" carbs and are they done correctly? (I've seen "rebuilt" carbs done by supposedly "good" Mechanics..Shouldn't have touched them)
3. What type ignition?
4. Where's the timing at?
5. Is Vacuum Advance working?
6. Are there any vacuum leaks??
7. What shape is rotor/cap in?
8. Have you checked Firing order?

[ottawamerc]

I'm guessing at a possible defective power valve or even the wrong one?

Scott

[boss429kiwi]

After going through a few tests, I can screw the mixture screws home with little difference in idle?

Engine was rebuilt by Ray Burton about 11 years ago. 12.5-1 compression, not sure why? Timing set at 0, and was told this is correct for this engine.

[Cooter]

That's alotta compression ...sounds like engine is running lean. Engine should go full rich with mixture screws out that far.

[boss429kiwi]

I have had enough!  

I will book it in to our local speed shop.

After reading a post about tuning 6 pack carbs, I raised the floats to mid point on the windows, lowered the idle (as it was set high so wouldn't stall), and set mixture screws 1.5 turns. It ran 90% better, no major stumbling, however still not right and still idles very rich?. When I remove the air cleaner, the idle drops and almost stalls. I can't believe that the air clear would be that dirty   but still not right running with no air cleaner.

Anyhow, I will now leave it up to someone else to sort out, as I am about to trade it for a Skoda!

Gary

[Cooter]

Skoda....haven't heard that one in a while. On our board, we had one member that loved those things...

[Mopar Nut]

Skoda....

Skoda? Cuda!

[boss429kiwi]

hey, where would I purchase a oval 1970 6 pack air cleaner?   repro OK

[Mopar Nut]

hey, where would I purchase a oval 1970 6 pack air cleaner?   repro OK

Summit or Jegs has them.

[b5blue]

I have had enough!  

I will book it in to our local speed shop.

After reading a post about tuning 6 pack carbs, I raised the floats to mid point on the windows, lowered the idle (as it was set high so wouldn't stall), and set mixture screws 1.5 turns. It ran 90% better, no major stumbling, however still not right and still idles very rich?. When I remove the air cleaner, the idle drops and almost stalls. I can't believe that the air clear would be that dirty   but still not right running with no air cleaner.

Anyhow, I will now leave it up to someone else to sort out, as I am about to trade it for a Skoda!

Gary

Is this what you read: http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Board=QuestionAnswer&Number=5995396&Searchpage=1&Main=5995174&Words=+Warrant_Officer&topic=&Search=true
There is a lot of good info in it.

[Cooter]

Skoda....

Skoda? Cuda!

Little English car...some early ones look like early BMWs

[Fred]

Sorry Cooter.  ................




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