Dave, the guys are just looking out for you! I am the lucky owner of a 470 (lol) so trust me, you will need to know all the inherent possible problems associated with these engines before you attempt to run on trailer. If it were me, I would remove all plugs and spray some lubricant into cylinders and let sit for a few days just in case the rings are starting to lock up on cylinders. (avoid scoring of cylinder walls and rings) Look at plugs carefully for any signs of steam cleaning effect from possible riser,gasket failure. Look for oil covered plugs also. (might give you some idea of condition of engine) Drop oil and while your at it check dipstick before you drop and inspect oil for signs of overfill,water intrusion, and or milkshake effect. If in fact the oil looks clean and at proper level ignore previous post. However, if it looks overfull and like a milkshake, do not attempt to run. (possible cam seal failure). Hopefully, that is not the case. Remove fuel filters, oil filters, remove and check inline fuel filter at carb base for dirt,etc. Remove cup from water pump and inspect for dirt,water,etc. Check plug wires,cap,rotor and point gap if it indeed still has points. Hopefully, it was upgraded to pertronix already. Check to see if it has the original oem water cooled voltage regulator along with the the rectifier at front of engine within the harmonic balancer on crank shaft. If this is the case, you will probably want to upgrade the points, oem voltage regulator,rectifier with an after market charging system. (alternator,Pertronix ignition) Drop coolant at 7:00 hole at bottom of timing cover. See if it flows and inspect for debris,rusty colored coolant, etc. If clogged up or lots of orange fine rust coming out, would give you a possible idea of condition of cam seals. (maybe) Replace plug, refill with 50/50 at the cap up top of the engine riser. Note, there should be a drain plug at bottom of heat exchanger at the very rear towards transom. That is a raw water drain for winterization. There should also be another drain close to that one and that is for the coolant. I would also change your thermostat, inspect all hoses for dry rot. Remove exaust pipes,donuts at rear of motor and look down into lower leg of exaust pipe that connects to inner gimbal housing and inspect exaust water shutter. Basically, see if they are there, melted, or simply missing. You need to have the exaust water shutters functioning on these engines or you risk possible water intrusion into cylinders via intake valves causing possible hydrolock while out on water. (engine will lock up and you will be broke down if you are not able to remove plugs out on the water. You don't ever want this to happen especially if running in salt water or you will surely ruin engine over time especially already knowing that the engine is old to begin with. Reinstall exaust sytem if all is well. Replace battery or batteries with good marine grade. Clean all main lug wire connections and battery connections. Check all main grounds thoroughly as well as wire integrity. (check for rotten cables) If it were me, I would remove the starter before I even attempt to put a load on it especially sitting around for two years. Hopefully, you have a Delco starter with built in solenoid. Don't be afraid to break down starter and inpect brushes, armature, etc. for rust. I cleaned mine up two years ago and it is still working great. There may also be an oiler on the starter drive. Lift little cap and give it a little squirt of oil so nothing would stick. That is if the starter is not completely locked up. Bench test it with alligator clips and 12 volt to see if it will spin and throw. Check bendix gear for wear or damage. Hopefully, all is good. You may have the prestolite setup with a remote solenoid that could be located under gunwhale or anywhere in engine bay for that matter. I don't care for that setup and would fully recommend the Delco starter setup but only if it is OEM. Don't buy any aftermarket starters unless you ask someone how they have made out with them in the past. (just trying to give you a heads up) Oh, before I forget and after you have gone through all of what I said above put boat on hose setup with ears and running water, see if the engine fires. If it does and you can get it to run at say 650-800 rpm, check your base timing with a timing light. If you have a Pertronix setup it will probably run best at around 5-6 degrees btdc. This is only to say if the carb is not all gummed up and everything is good and well. There is probably a purple wire that comes from coil wire harness that goes to your choke. The choke must funtion properly until warmup occurs so as to be able to idle properly. Maybe take off flame arrestor on carb and inspect. I would not adjust anything initially simply to see if it is working unless you have an idling problem to begin with. The choke has to be adjusted with a cold engine. My point is this: You should be able to idle at say 600-650 rpm after warmup and choke working properly. The lower the idle the better for initial base timing! These engines have a rapid timing advance curve. If you have the points setup, there was a Merc. bulletin that changed base timing from 8 degrees btdc to 4 degrees btdc. An older manual may tell you to set at 8 but it was changed to 4 for the points setup just so you know. The 5-6 with the Pertronix is up to you depending on how engine idlles,runs,etc. Also, under your points and or Pertronix setup you should inspect the mechanical weights and make sure the springs are intact and everything is clean and working as should. Check distributor shaft for play,wobble. (bushings) Hopefully, the distributor is in good shape. Also, if you have the Pertronix setup, regap plugs to no more than .040. You have to understand that the fuel is completely different than it was when these engines firts came out in the 70's.
I have forgotten what the gap is for points if you decide to run with them so you will have to read the manual for that. Check key switch wire to coil to make sure you are getting 12 volts. Check plugs with spark tester to see if the coil is working and you are getting spark. Check wires to starter for corrosion. Check all wires for corrosion. If you get engine to fire, check to see what kind of oil pressure you have if sender and gauge are indeed working, check voltage gauge to see if you are charging. You will know if it is charging or not over time by plug inspection and it will probably load up with unburned fuel and maybe backfire. Also, plugs will be all black with carbon with weak spark. It happened to me when I first ran my boat. Lube any grease fitting on the outer gimbal housing especially the grease nipple that lubes the actual gimbal bearing if it has a lube point. It should be at around the 3:00 looking at outer gimbal housing at top of drive. Don't start without lubing anything and everything that needs lubing. (steering upper pivot and at trim switches both sides) There are lube points for the steering inside on steering cable tube where it attaches to tiller. (wipe clean and lube with 2-4c) Make sure steering is smooth and don't force wheel if it is tight until you lube. (or you will be buying a new steering cable) Check power trim reservoir level. Check power steering pump oil level at top front of engine. Hopefully, if you have power steering, your power assist is not leaking. Mine was and I had to replace at around $150. Also, make sure you check your drive for oil. Drain and check for water,metal,etc. If everything is good along with pressure test then refill from bottom drain plug on lower unit until oil comes out of the upper drive fill level plug. Make sure drive is pretty level when doing this. Hopefully, your drive is not seized up and still intact. You will know this if you were to try and start with good battery,starter,etc. and the starter simply labors,clicks or seems to be under too much of a load. Hopefully, that is not the case, but you will know pretty quickly. The engine and drive are turning together when running all the way down to the raw water pump so if the drive is locked up, you won't be able to run the engine unless you were to remove drive and supply raw water directly to inlet side of heat exchanger. (hopefully that is not the case) Forward and reverse are engaged at the very bottom of the lower unit via the shift linkage but the drive is always turning when engine is running along with raw water pump. That is why it is so important to supply water to drive even running for only a matter of more than a few seconds because if not the hot exaust gases will go down and cook a brand new water impellar very quickly. Then you have an overheat condition which could blow head gasket or even worse engine failure. Also, try not to run engine on trailer,ears,hose at high rpms. I think your supposed to run engine at a maximum of around 1500-2000 rpms for short periods of time just to be safe. You will have to water test at higher rpms only. I posted this today only because I already went through alot of the things you are about to go through if you indeed decide to spend the time and money to get this boat up and running. Again, I provided alot of information (not all) that may help you get the engine and drive possibly to a running condition but I cannot physically see the boat,know it's condition,etc. I simply gave you a starting platform so as to give you a fighting chance. Post some pics. all the best, Tom
