Thanks, while getting title work done want to start getting it startable after sitting inside (climate controlled) house for 5 years. Any thoughts or gotcha's will help here. Obvious are flush fuel tank/lines, carb, points, wires/spark, crankcase oil, valve sponges, tires and general lube.
I did a '47 Chief a few years ago that had sat 20+ years in an unheated shed. Most of what I did should translate to yours.
Check and rinse the gas tanks. Mine had rust so I got a wash and seal kit from Greers. Check the head bolts. Mine were loose. I dropped the bowl on the carb and found a mushroom like fungus growing in there. I pulled the plugs and put a little Marvel Mystery oil in each cylinder (don't go crazy with it) then hand cranked it. Waited a couple days and repeated. I filed and gapped the points but you should have a magneto. Check the timing. Clean or replace the spark plugs. Check for wet sumping. On a Chief there's 2 drain plugs just below the front of the primary. The top one comes out to drain any excess oil in the bottom of the case. I don't know if a four has them in the same location. Change the oil. Mine looked like green pond scum. After a 100 miles I changed it again. Check the nuts at the bottom of the jugs for looseness. Rest of the bike: check all the nuts and bolts for tightness. Look for anything obvious in the wiring. Check tires for age cracking. If the chain is properly lubed it should look dry but a few drops here and there of 3in1 doesn't hurt. Check chain for too much slack. Check headlight aim. Point it a wall from about 8' and mark the wall with tape where the center of the beam is. Measure up to the headlight. Should be centered side to side and just barely pointing down.
Now you have to determine the cold starting procedure. Each bike has it's own quirks but here's how I start mine. Prime: Bike in neutral, clutch engaged, gas on, throttle full open, choke full closed, ignition off, give it one or two prime kicks, close the throttle, open the choke a notch and give it another prime kick. Open the choke another notch, roll the throttle about a quarter, roll the spark about half, ignition on, and kick. A well tuned bike should start on the first or second kick. The first time you start it should be outside as it will smoke like crazy for a couple minutes burning off the MMO. Start when warmed up: leave the gas petcock closed, roll the throttle about a quarter, roll the spark about a third, kick. Once started roll the spark back and turn the gas on (keeps it from flooding). If you're like the rest of us you'll realize you forgot to open the gas once you start down the road lol.
A few tips. Always warm it up before riding and work the choke the rest of the way open as it's warming. After a few minutes remove the oil cap and make sure there is oil coming out of the return line. It's not a stream - more a soft flow in spurts. It's a crashbox. The first time you shift into first after starting it will grind gears - normal. Do it this way. Once warmed closed the throttle to idle. Slowly roll the spark until the engine slows to just about stall. Disengage the clutch, pull the shifter sharply into second then sharply into first. Roll the spark back. Always use regular gas. High test burns too hot for that old soft metal. Don't use oil with a lot of detergent or additives. If you don't have one the first thing you should buy is the Indian Riders handbook. You will stall it - a lot, until you get used to the foot clutch. This all may sound complicated but once you ridden a while it will all seem normal and you'll never have so much fun riding a motorcycle.
If you haven't already join the AMCA (antiquemotorcycle.org) and get on the forum. There's guys there with Fours that know way more than I do and they'd be happy to help you out.