Seems like its always something

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mooreken
Posts: 588
Joined: Sat May 09, 2015 12:25 pm

Seems like its always something

Post by mooreken »

Tom loaned me his O2 meter and I have spent the week working with my carburetor, I won't say I'm working on it do the fact that I am not quite making the progress I would like.
The car does really run good. I just cant seem to get it leaned up the way I like it. The jets keep getting smaller but the plugs are still black.

I seem to have a curse the takes the form of someone telling me "I have never seen that before" I can't count the times that I have heard that.

Now to the curse. I've been keeping an eye on the timing to find a balance between idle and starting. Only moving it a couple degrees here and there. Yesterday evening I checked it and could not find the mark anywhere that it should be. So I'm thinking all sorts of wild reasons, like bad distributor gear, that maybe I had made a big error on something, a bad cap all those things.
So I did the finger in the spark plug hole thing and it goes poof before the marks get close.
I could only think of one thing that could cause this but I had bought a new harmonic balancer for the new build. But I cleared all the stuff that was in the way to get access and pulled it off.
Sure enough the outer ring of the balancer had slipped about 60 degrees!!!
I took it back to the hot rod shop and he was good about it and gave me another one. This is where the curse came in....He sells these all the time even to a lot of dirt track racers.....and he has never seen one come loose.
I have always read about them slipping but in my 50 years of motoring I also have never had one move.....
Now that the problem of the timing marks is handled...back onward to the carb....I got a feeling me and Holley's tech number will be close friends.
Ken
BlackSnake
Posts: 337
Joined: Mon Jul 13, 2015 4:09 am

Re: Seems like its always something

Post by BlackSnake »

Hey Ken, is that the same carb that was on the motor when it blew up? If so, could be that the power valve blew out and that's why its running rich with smaller jets?
mooreken
Posts: 588
Joined: Sat May 09, 2015 12:25 pm

Re: Seems like its always something

Post by mooreken »

No it is the 750cfm that I had bought for the first motor but I couldn't get it to do right on it so I bought a 650. I also thought it might be the valve but I checked it with a vacuum gauge and all is good. I have finally gotten a little color on the plugs but I'm down to a 65 on the front jets and 70 in the back. It started with 73's. I talked to Holley for about an 1/2 hour or so to try and get a feel of things, other than suggesting trying a couple steps smaller on the front to see and then play with the air bleeds not much other useful advice.
Now that I have a little color on the plugs I'm going to play with the air bleed screws. That will be new territory for me. I've never had a carb that I could change those.
I took Toms O2 back out I was afraid that I would mess up the sensor with all the carbon soot.
The main thing other than the small jets that keeps bugging me is the idle mixture screws. If I tune them for best vacuum or highest idle the front ones are screwed in all the way and the rear are out maybe a turn. It idles good but has a large hesitation when hitting the gas when driving. I can crack the fronts a half to one turn and the hesitation gets much better but the motor runs rich at idle.
Its getting fuel from somewhere....I just cant find out where. I have even lowered the float levels a little just to make sure that setting is not in play.
Even as well as the other motor ran, when I took the heads off the chambers and the ext. ports were black....and that was with the other carb. They are both the Holley Street HP. Just one is 650 and the other is 750.

The unfortunate thing now is that for the money I paid to buy both carbs 6 years ago...I could get fuel injection now. :((
BlackSnake
Posts: 337
Joined: Mon Jul 13, 2015 4:09 am

Re: Seems like its always something

Post by BlackSnake »

Sounds a lot like what I'm experiencing with tuning the Webers on the GT, no matter what I do the plugs are sooty black. :GR::
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