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Mon Sep 23, 2019 1:38 pm

So I removed the carburetor today thinking it may need to be cleaned. One thing I did notice is that the (flaps) not sure what there called, don’t move when the throttle is manipulated. Should these be moving?

Mon Sep 23, 2019 2:33 pm

Those are your choke butterflies. There are several mechanisms that effect their movement, primarily they move with relation to temperature, closed during a cold start and open fully once the engine is warm, there is an electrically heated bimetal coil with accomplishes this. They are also effected in a couple of different ways by engine vacuum and by the throttle. There should be a wire coming from the "+" side of the ignition coil to the choke coil.

When cold starting you want to pump the throttle pedal to the floor fully one time which among other things will allow the chokes to close. Stabbing the pedal as some point after the cold engine starts will cause the engine to idle down. On a cold morning you want the throttles to close fully as you pump the throttle and then after 5 minutes of so of running the choke should be open fully. The engine will bog if they don't open at the right rate, but better they open too fast than too slow.

The thick paper gasket is supposed to be between the carburetor and the base of the air cleaner and not on top of the base. Make sure those screws are Loctited in place as they will play hell is they work their way out and get sucked into the engine.

Mon Sep 23, 2019 2:38 pm

Wildthings wrote: Those are your choke butterflies. There are several mechanisms that effect their movement, primarily they move with relation to temperature, closed during a cold start and open fully once the engine is warm, there is an electrically heated bimetal coil with accomplishes this. They are also effected in a couple of different ways by engine vacuum and by the throttle. There should be a wire coming from the "+" side of the ignition coil to the choke coil.

When cold starting you want to pump the throttle pedal to the floor fully one time which among other things will allow the chokes to close. Stabbing the pedal as some point after the cold engine starts will cause the engine to idle down. On a cold morning you want the throttles to close fully as you pump the throttle and then after 5 minutes of so of running the choke should be open fully. The engine will bog if they don't open at the right rate, but better they open too fast than too slow.

The thick paper gasket is supposed to be between the carburetor and the base of the air cleaner and not on top of the base. Make sure those screws are Loctited in place as they will play hell is they work their way out and get sucked into the engine.

There is a paper gasket on the bottom. The other thing I noticed while spraying the carb is that one of the bowls is holding the carb cleaner and the other bowl is letting the cleaner drain. Is this supposed to happen

Mon Sep 23, 2019 3:02 pm

Get rid of the second gasket then, it is just going to fail and let the bolts loosen.

You have a progressive carb, one set of throttle plates opens first followed by the second set as the throttle pedal is push further down. When the throttle pedal is not depressed, the primary throttle plate is open a bit to allow enough air to pass for the engine to idle, while the other one is fully closed.

Mon Sep 23, 2019 3:51 pm

When you removed the carb, did you have to remove a wire from a round cover on the back side of the carb? It looks like from your photo that there was indeed a red wire in a sheath going from the coil to the back of the carb. This is your choke wire, that feeds 12v+ to the choke.

If you have gas at the carb, and you already have the carb off, I think you need to take the carb apart, check the float and needle and seat to make sure the float is "floating" properly (they can develop leaks and then dont "float") and the needle and seat are opening and closing. Debris can get in the needle and seat and then it won't close, thereby flooding the engine.

Time to get a rebuild kit and learn about your carb! Good deal for you.

Do you have the mechanical pump, or an electric pump? Bad thing about an electric pump in this situation is if you get a piece of debris in the carb stopping the needle and seat from closing, you can proceed to fill your engine with gas just sitting there with the key on.

Good luck
Hobo

Mon Sep 23, 2019 3:56 pm

HoboBus wrote: When you removed the carb, did you have to remove a wire from a round cover on the back side of the carb? It looks like from your photo that there was indeed a red wire in a sheath going from the coil to the back of the carb. This is your choke wire, that feeds 12v+ to the choke.

If you have gas at the carb, and you already have the carb off, I think you need to take the carb apart, check the float and needle and seat to make sure the float is "floating" properly (they can develop leaks and then dont "float") and the needle and seat are opening and closing. Debris can get in the needle and seat and then it won't close, thereby flooding the engine.

Time to get a rebuild kit and learn about your carb! Good deal for you.

Do you have the mechanical pump, or an electric pump? Bad thing about an electric pump in this situation is if you get a piece of debris in the carb stopping the needle and seat from closing, you can proceed to fill your engine with gas just sitting there with the key on.

Good luck
Hobo

There is a wire from the coil to the rear of the carb. I have a mechanical fuel pump. As far as a rebuild kit goes, is there a certain type I need. Are they specific to the carb or are they generic?

Mon Sep 23, 2019 4:16 pm

Check the brown manifold boots to see if they have backed off, are loose, or cracked. Those center mount carb conversions are hell on those boots.

Mon Sep 23, 2019 4:26 pm

Tram wrote: Check the brown manifold boots to see if they have backed off, are loose, or cracked. Those center mount carb conversions are hell on those boots.

The boots are fairly new. With no cracks

Mon Sep 23, 2019 5:28 pm

1966type1 wrote: HoboBus wrote: When you removed the carb, did you have to remove a wire from a round cover on the back side of the carb? It looks like from your photo that there was indeed a red wire in a sheath going from the coil to the back of the carb. This is your choke wire, that feeds 12v+ to the choke.

If you have gas at the carb, and you already have the carb off, I think you need to take the carb apart, check the float and needle and seat to make sure the float is "floating" properly (they can develop leaks and then dont "float") and the needle and seat are opening and closing. Debris can get in the needle and seat and then it won't close, thereby flooding the engine.

Time to get a rebuild kit and learn about your carb! Good deal for you.

Do you have the mechanical pump, or an electric pump? Bad thing about an electric pump in this situation is if you get a piece of debris in the carb stopping the needle and seat from closing, you can proceed to fill your engine with gas just sitting there with the key on.

Good luck
Hobo

There is a wire from the coil to the rear of the carb. I have a mechanical fuel pump. As far as a rebuild kit goes, is there a certain type I need. Are they specific to the carb or are they generic?

The rebuild kit is specific to the carb. You likely have a "Weber 32/36" variant.

Look at the flange where the carb mounts to the intake, or somewhere else on the carb, and you should see some characters stamped in the carb body.

Once you know the carb, search online for a rebuild kit. It will come with a new needle and seat, and some kits even come with a new float.

Look here or on YouTube for videos on rebuilding the carb, and follow along. It should show how to disassemble the top of the carb, how to remove the float, replace the needle and seat, reinstall the float, and check the float height.

Great opportunityfor you to learn about carbs and floats and such. There also should be a fuel screen-filter where the gas line connects to the carb. Be sure to remove and clean this screen filter.

Good luck,
Hobo

Mon Sep 23, 2019 5:37 pm

HoboBus wrote: 1966type1 wrote: HoboBus wrote: When you removed the carb, did you have to remove a wire from a round cover on the back side of the carb? It looks like from your photo that there was indeed a red wire in a sheath going from the coil to the back of the carb. This is your choke wire, that feeds 12v+ to the choke.

If you have gas at the carb, and you already have the carb off, I think you need to take the carb apart, check the float and needle and seat to make sure the float is "floating" properly (they can develop leaks and then dont "float") and the needle and seat are opening and closing. Debris can get in the needle and seat and then it won't close, thereby flooding the engine.

Time to get a rebuild kit and learn about your carb! Good deal for you.

Do you have the mechanical pump, or an electric pump? Bad thing about an electric pump in this situation is if you get a piece of debris in the carb stopping the needle and seat from closing, you can proceed to fill your engine with gas just sitting there with the key on.

Good luck
Hobo

There is a wire from the coil to the rear of the carb. I have a mechanical fuel pump. As far as a rebuild kit goes, is there a certain type I need. Are they specific to the carb or are they generic?

The rebuild kit is specific to the carb. You likely have a "Weber 32/36" variant.

Look at the flange where the carb mounts to the intake, or somewhere else on the carb, and you should see some characters stamped in the carb body.

Once you know the carb, search online for a rebuild kit. It will come with a new needle and seat, and some kits even come with a new float.

Look here or on YouTube for videos on rebuilding the carb, and follow along. It should show how to disassemble the top of the carb, how to remove the float, replace the needle and seat, reinstall the float, and check the float height.

Great opportunityfor you to learn about carbs and floats and such. There also should be a fuel screen-filter where the gas line connects to the carb. Be sure to remove and clean this screen filter.

Good luck,
Hobo

Thanks Hobo I plan to try and find a rebuilt kit tomorrow and spend my day off learning about carbs

Mon Sep 23, 2019 6:28 pm

1966type1 wrote: Tram wrote: Check the brown manifold boots to see if they have backed off, are loose, or cracked. Those center mount carb conversions are hell on those boots.

The boots are fairly new. With no cracks

It is the underside that tends to crack first and worst. Pretty hard to see from above. Maybe at least loosen the clamps on one of them, used a radiator hose pick to free up the boot from the metal and rotate the boot so the underside is brought to the top so you can inspect it.

Mon Sep 23, 2019 6:31 pm

Wildthings wrote: 1966type1 wrote: Tram wrote: Check the brown manifold boots to see if they have backed off, are loose, or cracked. Those center mount carb conversions are hell on those boots.

The boots are fairly new. With no cracks

It is the underside that tends to crack first and worst. Pretty hard to see from above. Maybe at least loosen the clamps on one of them, used a radiator hose pick to free up the boot from the metal and rotate the boot so the underside is brought to the top so you can inspect it.

I will do that tomorrow. Thanks

Mon Sep 23, 2019 7:50 pm

If you have a Spanish made Weber carb. Buy a rebuild kit by Redline. There are kits out there designed for EMPI clones. Apparently they don’t play well together.

https://www.piercemanifolds.com/category_s/286.htm

Tue Sep 24, 2019 6:12 pm

Could fouled spark plugs be the cause of my issue? I just pulled one plug and it was pretty black but still had good spark.

Wed Sep 25, 2019 10:39 am

1966type1 wrote: Could fouled spark plugs be the cause of my issue? I just pulled one plug and it was pretty black but still had good spark.

All signs point to that centermount carb as the root cause.

Time to 5 WHY that thing...

Wed Sep 25, 2019 12:14 pm

is there a cut off solenoid?

Wed Sep 25, 2019 12:16 pm

EDragnDean wrote: is there a cut off solenoid?

Not trying to sound stupid here but I have absolutely no idea what a cut off solenoid is

Wed Sep 25, 2019 12:35 pm

1966type1 wrote: EDragnDean wrote: is there a cut off solenoid?

Not trying to sound stupid here but I have absolutely no idea what a cut off solenoid is

Typically progressive carbs do not have shut off solenoids.

You can check if your carb is running to rich by unplugging the power from an electric fuel pump, or pinching off the hose on a mechanical pump. Then try to start the engine with the throttle held fully open. With the throttle fully open the choke butterflies should also be open. If not, use a pencil to hold them open.

Tue Oct 01, 2019 1:59 pm

Good news the bus now starts. Turns out there was a loose screw or nut under the distributor. All is now well. Thanks to everyone for the help