I have a 1974 f600 with a 361 my son & I are trying to resurrect. It sat for who knows how many years in a field. At this point we are only replacing parts that will get it started. Once it proves itself, then we will be more giving to it.
So far we've replaced the starter, plugs & wires. It almost started but didn't & now it just cranks. It appears to be sparking but I'm thinking its a weak spark. I want to test the coil next.
Does anyone know what the resistance would be to the coil?
If I do need to replace the coil, would a coil for a '74 360 from local parts store work with a '74 361?
Thanks,
JQ

 

If I'm correct it should be around 2 ohms from negative to positive side of coil and about 9k ohms from positive side to the coil tower.

Try holding a spark plug a 1/4 inch away from a ground and see if the spark jumps across. If you get nothing then pull the cable that connects the dizzy cap to the coil from the dizzy cap and do the same thing(make sure you put plug back in before hand). If your still getting nothing that's jumping a 1/4inch then I'm pretty sure it's your coil. It might not be a bad idea to check your condenser and points in the dizzy. That seems to be the usual cause of ignition problems.

 

If it has points, try cleaning the contacts with (very fine) emery paper. Coils go bad at times, but they often get needlessly replaced when the problem is somewhere else. Don't replace condenser with anything but NOS or Autolite/Motorcraft. The parts store sell chinesium and these have proven to be junk. The points are not much better.

 

Thanks Henry! I'll give it a shot.
JQ

 

No problem, keep us posted

 

Thank you as well, Tedster. I will check that out as well.
JQ

 

Son tested the coil & the posts came back with a 1.5ohms & the post & tower came back at around 6k.

 

If you have a spark at the plugs, the basic ignition system is OK.
A poor spark can be caused by points set too wide (condenser not
having enough time to charge). Set them with a dwell meter. Then
check your timing. Manual method is good enough to start the
engine (points just start to open at 8 degrees). For a truck that has
been sitting for a long period, I first suspect a fuel problem. Old gas,
clogged fuel pump or varnished up Carb.

 

I'll check the points & go from there. We cleaned out the fuel tank as best as we could & disconnected the fuel line from the carb. We sprayed some carb cleaner into the carb & have been using that "engine starter" stuff to try & start it. Might spray more carb cleaner & let it sit. Not ready to pull the carb yet but I realize that may have to happen. Greatly appreciate the help.
JQ

 

6k ohms for the secondary on the coil sounds a little low, but. Spark at a plug should be fat and bluish-white. Red or yellow, thin spark is no good and won't fire when under compression. Keep battery on charger while troubleshooting.

 

Sounds pretty low to me. Have you tried pulling the cable from the dizzy cap to the coil and checking your spark?(leave it plugged into the coil as that's what your testing). It sounds like you may need to get a new coil.

 

as far as bad gas goes have you tried spraying stater fluid into the carb? Another trick I've used is to just take the top plate of the carb and manually remove the gas and then reinstall the the top plate. Then disconnect the fuel pump hose from the end that connects to the main line that leads to the tank, Then place the fuel pump hose in a gas can filled fresh gas. Pump the throttle and if your pump is working and has pressure it should fill your carb up with fresh gas.

 

I love those trucks! Very reliable and durable; you probably have just minor issues...I've just gone through the issue of ignition spec's for the '74 year- there are actually 3 different plug gaps listed for 360, including the heavy-duty version you have, which is .035