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After having the pinz sit for the last 7 or so years I am finally trying to get it running again. I am sure I have a few posts asking for help but decided to start anew since it has been so long.

1975 710
HISTORY..
When I purchased it,it did not run due to a fuel issue which I resolved. After that I ran it down the freeway going 60+ and it ran great. I did not drive it much before it started to run rough and I have not gotten it running right since.
I installed a Pinz SSI system with new plugs, wires, etc. Rebuilt the carbs, synced the carbs, checked compression, checked valve adjustment.

Here is how it is currently running.

https://cdn.discordapp.com/attachments/ ... 6856_n.mp4
Starting it up and feathering the throttle

https://cdn.discordapp.com/attachments/ ... 9132_n.mp4
This is when I try and accelerate fast.

Any advice appreciated.

I'm anxious to see the responses. Mine does the same thing. I just assumed it was the accelerator pump and was going to address it when I redo the carbs. On mine, once its warmed up, I can very slowly accelerate and it will do so without a stumble. On a normal acceleration though it balks and tries to quit, so I feather it until its off idle then it runs fine throughout the rest of the range.

-RP

Looks like some pre-ignition?

Re-check your PinsSSI timing. It should be 3mm to 5mm advanced.

It's possible the timing disk moved in relation to TDC. The distributor
"pinch-clamp" may be loose or the screw locking the timing disk may
not be tight enough. Either could result in timing drifting while driving.
Both causes happened to me

Going to recheck timing but waiting on TDC tool to make sure my mark is in the correct location, etc.

Checked all 4 cutoff solenoids and they click.

Tried to take temps on the exhaust but my IR thermometer was kind of all over the place. After the truck had been shutoff for a bit cylinder 2 exhaust was definitely hotter than the other 3.

So in the end my issue was either a plug wire not on all the way or a bad spark plug. Changed the plugs the other day and now she runs great and backfiring is gone. It has never ran right since I put on the ignition system which included changing the plugs so just never thought to change the new plugs..