I've never done either but need to learn how...

I was 4x4'ing in the hills above Big Sur last weekend and noticed my truck idling poorly after a particularly rough climb. I "messed" with the distributer thinking that maybe it had slipped. I also messed with the fuel adjustment screw on the carb. Then, I found out that the bolts that connect the exhaust to the header were very loose with an air-gap, and tightening them made a significant improvement. I was able to drive home, but had very little power. I could hear knocking anytime I tried to give it too much gas.

Now I need to re-adjust and re-time to fix my prior "messing with". Can anyone give me some direction on how to start? I have a timing light, and I'm going to replace the fuel filters and air filter before I begin... its a 1970 F250 with a 360 and stock 2bbl carb.....thanks

 

What you hear is most likely spark knock. Loosen the distributor & turn it a little in a direction. Snug down & test drive. Better or worse? Adjust accordingly. If worse go the other way with the distributor. If better but still there keep going as you are. Once you get the spark knock out of it make sure it is warm & try to start it. Crank ok or hard starting? If ok you are done. If hard starting keep moving the distributor until it cranks ok when hot.

Carb: With the truck warm & at idle turn the mixture screws in until the rpm starts to drop. Now outward to achieve max rpm. If your idle gets much above 750 you will have to back the idle screw off a bit to keep the carb in the idle circuit.

 

After you confirm TDC and the balancer's timing marks read zero you can proceed...

On a stock 360 i'd set initial at 6-8 degrees BTDC, you can always bump it up if need be, but be aware of detonation (pinging).

 

Does this truck have points? If so they should be set to somewhere between .017 & .019 if I remember correctly. A matchbook cover is the correct thickness.

 

I think I made a mistake... I put a light on it and set it at around 8 deg, and it runs well EXCEPT the exhaust smells very strong of gas. I didn't make sure the engine was at TDC. So just to clarify, I need to make sure its TDC and THEN put a light on it???

 

Get a vacuum gauge and hook it up to manifold vacuum. Turn the mixture screws in, an even amount each until the RPMs start to drop off, then slowly back the screws out evenly, just until maximum vacuum is achieved.
You will need to adjust timing and engine idle at the same time. 10 degrees is a good setting for a 360. Hook up a Tach/Dwell meter to monitor the idle while setting the timing. Some guys like an "in gear" idle 650-750 RPMs, but the manual says "curb idle" on a 360 should be 550. Manual says initial timing should be 6 degrees at curb idle, I prefer 10 degrees, initial.
Set timing with vacuum advance disconnected and the vac line plugged.
When you change the timing, it will affect idle RPM and vice versa; keep adjusting both until the idle and the timing are both simultaneously within spec.

 

Any chance that you might have picked up a tank of bad gasoline in some back country filling station? Before you go into the motor I suggest you run the tank out, refill it with local gas and see what happens.

 

2x CougarJohn.