... now, do a compression test on , #3, #5, #7 lets see if #7 is much lower, indicating a bad valve

 

#1 and #7 left to right. 4 and 8 looked the same

Compression test, do I need all plugs out?

 

#1 and #7 left to right. 4 and 8 looked the same
Champion 25, rv17yc with .35 gap

Compression test, do I need all plugs out?

 

that looks like a rich F/A mix .. is the choke releasing after running short amount of time? do you hear popping in the exhaust ? and no, you don t need to remove all plugs to check compression.

 

Fuel/Air mix ... the plugs look carboned ,sooty, too much fuel ,, too much fuel can cause hot exhaust, but not typically just one tube.... what carb are you using? do you hear popping in the exhaust?

 

Rebuilt Holley 600 with electronic choke.
The idle mix is still at 1.5 turns out... dont have a vacuum to set the mixture right now.

They are new plugs.... the previous owner had Accels 276s and had a gap of .25... where now i have the champions 25 rv17yc with .35 gap... recommended by champion, and two chain auto stores.

I did a comp test on 1 and 7 and im getting pretty much 130 on both.

No exhaust popping

 

OK, compression good, so valves should be good, one more thing eliminated....... does it idle good? Do you know what your maniflod vacuum is at idle? and what power valve was installed when carb was rebuilt?...plugs look like your getting a lot of fuel

 

It idles ok, but probably a little high or it will stall.
I dont know the idle speed of the engine (need a new tach boad i suspect)
And i havent got a vacuum gauge to use right now.
Im not sure on the power valve im afraid.

Could they look like this cos most of there life i was doing the timing on them from new... so maybe not a true representation of mixture now the timing has been set?

 

prolonged idling with choke on can do it..thats why I asked if it is releasing [butterfly blades opening all the way ].. you can just disconnect the hot wire to electric choke.... if you could drive the car, then pull again, they should look better .. I m assuming you have a dual plane manifold, so , look into carb front bores, while its running, see if fuel is dumping from nozzles, more on the left side ?.. I m thinking it may be flooding on that side..but, you say no popping in exhaust? we have eliminated all the mechanical reasons for the hot tube, what we have left is either fuel or ignition.................unless somebody has another idea, please jump in

 

No popping at all... still think its flooding it?

I will have to try driving it another day, the neighbours probably hate me after this weekend already.
The hot wire would be the red wire?

I spoke to the previous owner and he said it has 68 jets and 6.5 power valve. does this sound about right, it means nothing to me.

 

thats stock for a 600cfm, so yeah, thats about right.. have you looked in the front bores while its running to see if fuel is dripping on that side? the previous owner never had it running?

 

Yeah he had it running, it's just that I noticed one header was glowing. It's had 0 miles on it since the full restoration and engine work.
I bought it part finished. I installed new headers on it to archive side pipes, so I never ran the other headers. But looking at them the #7 only primary it looks to have a darker tint to it kinda purple, so it was getting hit with those on also.

I ran out of day hours so couldn't run the engine to check.
But I pull off the cleaner, and am I looking for a needle type part or?

 

yeah,remove cleaner . look into top of carb... there are small two nozzles ,one in each bore at the top , if the carb is flooding, you will see fuel dripping at idle .. see if one is dripping and one is not, thats the best way I can explain.. if you have a dual plane manifold, they cross sides.. also, do you know how to check the float levels? theres a small sight plug on side of each bowl, place a rag under it,unscrew and remove the plugs , the fuel, while idling , should be at the bottom edge of the hole...if it keeps coming out the hole, the floats are set too high, flooding... from the looks of your plugs and the fact it stalls if you slow the idle, leads me to think its flooding.. its very hard to diagnose a problem like this, by descriptions .. if I was there, well, you know what I mean..

 

I will give it a go over the next couple of days, I may pm you some questions as this is all new to me.

Am I checking this with the + wire on or off the electronic choke?

 

Of all the replies this seams the most likely , pull the header and check gasket and weld .

 

As in one if my replies it was doing this with different header with a different gasket

 

definitley looks to be running on rich side...

 

I know its a long thread, but if you read it, , you will see that he replaced both header and gasket ..glowing both before and after.. so not really likely at all ,

 

Wrong.

He's only assuming that it did it with the other headers.

 

its easy to come along after every possibility has been eliminated and be the "expert" /and tell everyone they re WRONG! .. I see no point where you offered any assistance whatsoever.. at least I helped him eliminate every possibility one by one.. what did you do to help along the way?? and actually,what the op said... , "so I never ran the other headers. But looking at them the #7 only primary it looks to have a darker tint to it kinda purple, so IT WAS GETTING HOT WITH THOSE ON ALSO " ............. he says #7 was hot on them too.. ..................... new headers and new gasket,no leaks.. did not stop the tube from getting hot..and how does a header gasket leak explain all 8 of the plugs being black and sooty or the poor idle or the stall if he slows it down?/ sorry, but thats not the problem, in my opinion... but by all means, you are the expert,solve the mystery for him ..I ll stand aside..