VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Problems With My Fresh 216 Engine

First of all oil leaks from a small hole in the block just under the breather tube on the right side. Can't tell if it's threaded or not. What's the purpose? How do I plug it?

Secondly, the engine starts and runs like a top, but dies if you reduce the choke to about a third open. The engine then begins to rumble like it has a full cam. Any further opening of the choke and it dies like you shut off the ignition. Strangely, it will not run below about (a thousand rpm?) but runs perfectly at higher rpms. The carb is professionally, just rebuilt and was engine tested. I tried checking for vacuum leaks and can find none. I even plugged the wiper line. Thanks for any input.
Roger

Small hole (should be two?) is suppose to have a bolt through it that holds a splash shield in place inside the block to block oil from spraying out of the road draft tube.

Check your ignition timing to make sure it is not too retarded and your dwell/point gap. Has the carb sat for long since it was engine tested?

Roger,

Is there a piston rod sticking out that hole?

Seriously,, I can't think of anything on the lower front passenger side of the engine except for the fuel pump.

Can you post a picture of ” hat hole"

As to the engine running, something is wrong. Jethro Bodine (Beverly Hillbillies) and I may be related. rocket science there. Anyway try these things:

a. Try adjusting the idle mixture screw. Should be already set but you never know.

b. Check the timing.

c. Check the points, etc.

d. Check the adjustment of the choke paddle.

f. Just drive it for a while and it will probably clear right up. No, I was not a used car salesman. "F" was thrown in just to see if you wuz paying attention.

g. Ask a friend to have a look at it. Make sure he has grease under his fingernails,

I hope you get it running smoothly soon.

Best,

Charlie

Masive vacuum leak.....most likely intake to head or insulator under carburetor....what make of carb?

That's what I thought too. But I tried the propane test around those spots with no effect. The carb is W-1 420S.

You are right. There are two holes. One located on a rib and one on the flat side. I don't even remember a baffle in there but it makes design sense. Funny thing, oil pours out those small holes but not a drop has come out the draft tube yet. That's at about 900 rpm, sitting in the garage. No idea what it would do on the road.

Charlie, timing is at 0. Points are .018. Choke is wide open when knob is on the dash. Throttle plate is completely closed when throttle/accelerator are released. I know the choke works because it won't run with less than 1/3 choke and about 1/3 throttle. I've never seen one run any smoother than this one at that setting. Will not idle under any circumstance though. I've tried the idle jet at everything from1/2 to 3 turns out. Made no difference at all. Blew air through the idle jet. The carb was run tested before it was shipped to me so it is fresh. I just don't know. I'll check everything again tomorrow for specs. Thanks for the humor. I needed some.
Roger

Valves set correctly?

Gene, I used the #1 - #6 method to set the valves. Only thing is the were not engine hot when set. I figured I would get it running and then set them at a slow idle like I always have done. Listening to the exhaust there are no muffled pops. Purrs nicely. Nothing unusual coming back out the carb either. I'll check the timing and points again today. It's been several months since I did that because I was waiting on the carb.
Thanks, Roger

Hi roger,

Given all the diagnostics that you have done so well I have to encourage you to take a deeper look at the carburetor. This appears to be a fuel related issue. I know it was rebuilt and performed as expected on a test engine.

I would be very suspicious that there is some dirt in a passage or blocking a jet somewhere. It could have been introduce into the fuel system when you went through the process of re-installing and starting the engine. It could have been in the tank or fuel line from the tank and quickly moved to the carburetor

Is there any way you can easily either put your carburetor on another engine or borrow a known good carburetor to put on your engine temporarily? That is a quick way to confirm if it is the problem.

I also suspect there is a plug in the idle circuit. The best way to check it is to: take the carburetor off the manifold, drain any gasoline, take out the low speed jet (it is the small slotted screw on the bottom side near the float bowl), take out the idle mixture screw, plug the hole in the throat near the throttle plate and blow air into the port where the idle mixture screw was removed. The air should now flow from the bottom near the throttle plate & throttle shaft and some exit where the low speed jet was removed. The air will also exit a couple of other places (main jet, etc.). That is the reason to use the blow back test and not blow forward to test it. If air flows then check to be sure that the itsy hole in the low speed jet is open.

If air does not flow freely then it will be necessary to remove some of the passage plugs and rod them out. The rebuilder should be contacted to do that process.

Clean out low speed jet the easy way.......
Place #3 spark plug wire on #4 Cylinder and #4 wire on #3. Remove air cleaner. Start engine and tromp down on the acceleraotor pedal a few times. The engine will back-fire and blow out the dirt.






the 1940 and prior has a very small opening in the low speed jet and they are prone to having this problem.

Sounds like Gene's way is a quick and easy way to solve the problem, I'll bet it works!

Gene's way often works but not every time. Depends on size, location and amount of blocking crud.

I agree with Chipper, it is easy way but doesnt always work.
Tony

it is a lot faster than reoving the caburetor, removing the casting plug and then digging in there to remove the low speed jet. By the way the low speed jet is not supposed to be removed and reused.
I have had 100% sucess with the fast way......if that is te problem.

Rusty, I have a glass bowl filter with a new element ahead of the carb. Possibly brought in the carb? Filter and bowl are pristine though. No extra carb for testing. Thanks for considering. Roger

Gene, do I need a good fire extinguisher at hand before I try the "quick method"? I more than trust your judgement on these matters. The rebuilder installed new jets, but perhaps a small piece of trash dislodged in the interim. I'll try Monday.
Roger

Chipper, if Gene's quick method happens not to give success, I will surely try your advice. I would never been able to put the procedure together as you did.
Thanks, Roger

Another method that sometimes works is drive down a steep hill in a low gear at 1/4 open throttle and pull the choke on briefly as you lift the accellarator.
Tony

I have a glass bowl filter ahead of the carb on a 37 and started to have some carb related trouble . I was sure it could not be trash in the carb but it was . I have cleaned and checked adjustments several times in the past year and changed the filter element every time . The trash is very fine . I guess it came from the old steel line even though it was cleaned or blown out pretty darn good in the beginning.

You will not have a fire hazad.

A fuel filter will NOT prevent all dirt from entering the carburetor.

Closing the choke will do nothing because the choke is spring loaded and will open under the air rush.

Rog,

Is the idle screw on the carb linkage set correctly for idle. Sounds like the engine is merely starving for fuel.

Sometimes the simplest things can give us headaches. Just a thought on what may be the problem.

This instant problem is puzzling and I suspect the remedy is simple.

If all else fails to identify the problem, borrow a 45 and put a round in the center of the carburetor. It won't fix the problem but make you feel better.

Best,

Charlie

Would you tell us what you did to FRESHEN your engine. If none of the easy fixes works you might find that the timing gear was not installed correctly. BEEN THERE DONE THAT. Please keep us informed

Good luck, Mike

Mike , that was a thought way back before I had the carb rebuilt. New everything in engine. Only old parts are the rods that have been machined for inserts. Marks on timing gears align properly. But I had to take off everything up front to prove it to myself that I didn't commit an old timer's error. I did that because without the new carb, I couldn't run it at any speed. At least it now will run fast. I tried crossing 3 and 4 wires and backfiring it several times today. No luck.
Appreciate the extra brain cells on this. Lord knows I can use them.
Roger