Had it with the Teapot carb! Argggg.....

[bigd1101]

Originally Posted by Kurt in NJ

when i put the 49 mercury engine in the 46 big truck i carefully set the distributor advance to the exact vacuum specifications, the teapot just got a kit and cleaning, good power, good fuel economy (could get 18 mpg with 2 ton load if kept under 60), it is important to have the vacuum correct

Getting the carb back. No problems with that. The builder sent a video of it on his test flatty. Ran like a dream. Looks like it could be a vacuum problem. Without too much hunting, where would one start. Is there a way to "pin-point" or narrow down the search to make life a lot easier? You know.....a "list" starting with priorities or obvious sources of a leak or leaks?

[rotorwrench]

It could be an intake gasket problem for either the deck fit or the carb flange. Intake manifolds can corrode or crack but it's not common. Windshield wiper hose or fitting could leak duty to poor condition. The distributer vacuum can is an item that can crap out and the small vacuum line is vulnerable to kinks and leakage to some extent. Shake check the distributer shaft and insure the bushings aren't worn out.

Once a person insures all the components are good, the troubleshooting can go on to other things like sticky valves, intermittent ignition components, or other possibilities like a funky fuel delivery system.

[bigd1101]

Originally Posted by rotorwrench

It could be an intake gasket problem for either the deck fit or the carb flange. Intake manifolds can corrode or crack but it's not common. Windshield wiper hose or fitting could leak duty to poor condition. The distributer vacuum can is an item that can crap out and the small vacuum line is vulnerable to kinks and leakage to some extent. Shake check the distributer shaft and insure the bushings aren't worn out.

Once a person insures all the components are good, the troubleshooting can go on to other things like sticky valves, intermittent ignition components, or other possibilities like a funky fuel delivery system.

Rebuilt engine, so I don't think there is an issue there. The dist. shaft is secure and tight, and the engine rebuilder said he didn't see a problem there, as far as bushings go. I checked the dist vacuum can and the diaphragm doesn't leak. I'm leaning toward a leak somewhere in the lines or a dist setting is off a tad. It could be a long drawn out process, but I'm retired so what the heck

[Bill OH]

Ignition wires - solid core? Distributor cap crack? Coil primary reversed - positive on coil to distributor if positive ground on battery? Cracks in the distributor cap can drive you up a wall.

[Merc Cruzer]

Originally Posted by bigd1101

Rebuilt engine, so I don't think there is an issue there. The dist. shaft is secure and tight, and the engine rebuilder said he didn't see a problem there, as far as bushings go. I checked the dist vacuum can and the diaphragm doesn't leak. I'm leaning toward a leak somewhere in the lines or a dist setting is off a tad. It could be a long drawn out process, but I'm retired so what the heck

This prior post may be of some help:

https://www.fordbarn.com/forum/showt...g+vacuum+leaks

[scicala]

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Originally Posted by bigd1101

Rebuilt engine, so I don't think there is an issue there. The dist. shaft is secure and tight, and the engine rebuilder said he didn't see a problem there, as far as bushings go. I checked the dist vacuum can and the diaphragm doesn't leak. I'm leaning toward a leak somewhere in the lines or a dist setting is off a tad. It could be a long drawn out process, but I'm retired so what the heck

I've read and re-read all of the comments and still don't really see what the performance issue was. Was it a lack of power, roughness or hesitation ?
Lack of power, but still being smooth points to lack of timing advance.

Sal

[bigd1101]

Originally Posted by scicala

I've read and re-read all of the comments and still don't really see what the performance issue was. Was it a lack of power, roughness or hesitation ?
Lack of power, but still being smooth points to lack of timing advance.

Sal

Inconsistent idle to start with. Like the car has a mind of it's own. The idle mixture does not hold a setting. The car seems to lose its setting when revved up. My mechanic tried to set the vacuum with a gage to no avail. He said he could get it to idle OK but when you revved the engine the carb would get out of adjustment on its own somehow, no matter how many times he would try to reset the air/gas screws or redo the vacuum. I had the same problem in my garage. The auto-choke (on the manifold) seems to work like it should at start up and shut down after warm up but when you restart the car cold the next day, the idle setting appears to have been moved (up or down)

Like I said, the carb rebuilders sent a video on the carb on their engine and it runs great and shuts down when the two mixture screws are set all the way in. Would weak springs on those screws cause the inconsistency?

Also is the hesitation when you stomp on it. A somewhat rough idle too. Not bad but could be smoother.

[alchemy]

Ignition is my guess.

[bigd1101]

Originally Posted by alchemy

Ignition is my guess.

I'll let all know when I figure it out. Got some specs on dist. settings and timing. After checking for vacuum leaks, I'll go there....

[rotorwrench]

I'd check the power valve function and condition. Any internal fuel or vacuum leak could cause odd idle behavior. I'm not as familiar with that carb as I am with the 885 and they have a different power valve system.

[Merc Cruzer]

You might want to just disconnect one the vacuum lines, and put a gauge it it, to see how steady it is.

Put a timing light on it and see how steady the timing is. Then slowly open the throttle and see if the timing remains steady. Then, hit the throttle and see how long it takes to change the timing.

Any of the above tests not performing as it should, would seem to point to a vacuum leak, not holding the vacuum can arm steady, and allowing the distributor to back off the correct advance.

[bigd1101]

Originally Posted by Merc Cruzer

You might want to just disconnect one the vacuum lines, and put a gauge it it, to see how steady it is.

Put a timing light on it and see how steady the timing is. Then slowly open the throttle and see if the timing remains steady. Then, hit the throttle and see how long it takes to change the timing.

Any of the above tests not performing as it should, would seem to point to a vacuum leak, not holding the vacuum can arm steady, and allowing the distributor to back off the correct advance.

I've eliminated the carb as the problem at this point after watching it perform on the video the rebuilders sent me. And yes, the vacuum is one area I'll test for sure.

Could I plug all the lines other than the metal one from the carb to the dist can and see if that helps? If it does then maybe there is a leak in the flexible lines somewhere, such as the wipers..... ???

[Merc Cruzer]

Here are the two vacuum lines going to the car, off of the carburetor. You could pull the hoses off of both and block them and give it a try. If it were me I wound start with the smaller one, since that fees the washer, wipers etc. The larger one feeds the power brake master and the storage canister, under the car.

[deuce5wndw]

If it has power brakes that could be your vacuum leak. I have had the diaphragm in the booster dry out and crack creating a vacuum leak.

[bigd1101]

So, while waiting on the teapot carb, I decided to clean the manifold mount. On it was this strange gasket I'm showing here that was under the regular gasket you mount the carb on. Why it was there was beyond me and I noticed that it has two cut-outs that extend over the mount that appear to be a source of air to the outside of the carb mount directly into the bore of the manifold. With the regular two-hole gasket over it you can see that the cutouts in the one below, are NOT restricted leaving two holes to the outside of the carb.

What is this gasket, and do I need it or is it the source of all my headaches? Please see the photos I took and let me know your thoughts?

[51 MERC-CT]

That is to me a big vacuum leak. Remove the gasket.

[bigd1101]

Originally Posted by 51 MERC-CT

That is to me a big vacuum leak. Remove the gasket.

And...the bane of my existence The question is.......why was it there in the first place? It was glued down to boot!

So just use the one (correct) gasket I have and hope that solves this mystery?

[51 MERC-CT]

Does your carb. have a groove in the base that corresponds with the length between these two holes?
If so then the carb base gasket should have two holes that line up with the two in the manifold.
This is to allow passage of hot air for the operation of carb heater.

[Merc Cruzer]

Originally Posted by bigd1101

And...the bane of my existence The question is.......why was it there in the first place? It was glued down to boot!

So just use the one (correct) gasket I have and hope that solves this mystery?

It would be the first thing to go for me!

[bigd1101]

Originally Posted by 51 MERC-CT

Does your carb. have a groove in the base that corresponds with the length between these two holes?
If so then the carb base gasket should have two holes that line up with the two in the manifold.
This is to allow passage of hot air for the operation of carb heater.

That's a good question. I'm waiting on the carb and it should be back soon, after they tested it as I stated above. The gasket as you can see does not nor did the weird gasket shown that was a source of leaks. Those two holes were covered, and I think were covered when I bought the car a year ago. That gasket I'm pretty sure was there when I did.

How would that effect the operation?