I am preparing to start a rebuilt 235 for the first time and I am hoping someone can give me a little guidance on a few questions I have. Let me start by saying that I have never rebuilt an engine or even started a carbureted engine so go easy on me. I have searched through the forum and internet and I think I have the basics (primed oil pump, timing set, valves adjusted, etc. etc.) taken care of but there are a few questions I have not been able to find an answer to.
1) I am using a rebuilt (by UREMCO) Carter YF 2100S. This is untested but its all I have. Should I pre-fill the bowl before trying to start the engine? I have a gas can rigged up to the mechanical fuel pump but I do not know how many engine revolutions it will take to get gas to the carburetor starting with dry lines. I attached a picture of the carb. There is a vent to atmosphere that I assume goes to the bowl. Should I fill through this hole? How much do I need to put in there? Should I braze over this hole when I am ready to put the engine in the truck. It seems like a good way to get a lot of dirt and debris into the carb having that big of a hole. Is that factory? It is also vented to the center of the carb above the choke plate.
2) Can I start the engine and do the 20 minute test run on just a charged battery without a charging system hooked up? My generator is rebuilt and untested as well so I really do want to mess with the generator/regulator during this test run. Do I need to set up a battery charger to trickle charge the battery as its running? Can I leave the generator in place and let it spin from the belt without any wires hooked up to it or will that damage something electronically?
I am a believer in filling ANY carburetor that has been off the engine prior to starting.
I have never been concerned about dirt into the vent; but if you are, a piece of masking tape covering the hole until you are ready to start the engine. DON'T FORGET TO REMOVE THE TAPE
Will leave your other questions to others.
Jon.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
An engine will run for several hours on any battery with enough current capacity to crank the starter. There's no need to trickle charge the battery for the few minutes it's going to supply ignition power during a break-in run. Ditto for the generator- - - -using it as an idler for fan belt tension won't hurt it at all. Fill the float chamber through that big vent tube over the choke plate until the gas runs out of the small hole in the casting you mentioned. The engine should run for a minute or so at idle on the gas in the float chamber if everything else is working right.
You need to have the engine tuned as well as possible before the first start- - - -no tinkering with valve adjustment, ignition timing, etc. while you're doing a run-in on the camshaft. As soon as you see oil pressure, bring the RPM up to around 2K and hold it there for 20 minutes or so. Run a big fan in front of the radiator, or trickle water from a garden hose over the radiator to prevent overheating during the run-in. Once the cam break in run is done, then you can deal with fine tuning like idle mixture adjustment, ignition timing, idle speed, and such. Good Luck! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Your biggest concern will be oil pressure and keeping it cool. Water over radiator really helps, and fans to remove heat from around the engine, move out doors if all possible. If you have a second radiator laying around, you can plumb the heater hoses to it with aux fan to help keep it cool. Once it starts, it's best to keep it going, no starting and stopping!
