26 Buick master six surging

[Hube1iam]

I just acquired a 26 master six in pretty nice condition but it surges on idle. Cleaned tank and replaced fuel. It had been converted to an electric fuel pump and the pressure regulator was leaking. That was replaced with a Holley regulator running at 1 lb. It seems like the heat riser plumbing is missing and capped. It starts easy but the air mixture screw needs to be turned in well past the  recommended  location. There is some seeping around the gaskets and moving parts but I can’t locate a kit and I’m afraid to remove the carb before I find one. Any suggestions? Thank you

Edited December 19, 2021 by Hube1iam
Typing errors (see edit history)

[Hubert_25-25]

Use this link.  You likely will have to create a username and password.    

 

https://brassbuicks.groups.io/g/PBR/files

 

Look in the files section.  There is a file called "Carburetor-Marvel-rebuilding.pptx".  There are numerous repairs that need to be made to a Marvel Carburetor to get them back in operating condition.  

Hugh

Edited December 19, 2021 by Hubert_25-25 (see edit history)

[Hube1iam]

Thanks Hugh. I’ll try that

[michealbernal]

You might also try obtaining a copy of the book "Carburation in Relation to Service" by the Marvel Carburetor Co.  I got my copy from Bobs Automobelia.  It has numerous drawing and pictures and explains exactly how to overhaul and set up one of these units.  There are several key measurements  that must be maintained for Marvel Carburetors to operate correctly.    I believe Carb King has parts including gaskets and floats.  

[likeold]

A different beast but my 38 Buick was doing the same thing, found the timing to be way too far advanced, retarded it and she runs much smoother, no surging.

[Brooklyn Beer]

Have you sprayed around the carb base and such with carb cleaner looking for vac leaks?

 

[Hube1iam]

Yes I’ve tried the check for external vacuum leaks. Michael do you have contact info for Carb King? Is the Carburetor king in LA. Thanks all again. I think need a kit before going any further as it’s seeping pretty much everywhere. 

[Brooklyn Beer]

1 minute ago, Hube1iam said:

Yes I’ve tried the check for external vacuum leaks. Michael do you have contact info for Carb King? Is the Carburetor king in LA. Thanks all again. I think need a kit before going any further as it’s seeping pretty much everywhere. 

He is on here regularly.  There is not much internally to rebuilding these carbs. On my brass bowl carter for a 31 Plymouth I had to get some drill rod sized drill bits to open up the idle tube but the limited number of parts inside amazed me.

[michealbernal]

Try as I might I could not come up with any info. on Carb King.  I did find a

couple of others that I had bought parts for my Marvel carb from and they are

 1.  Northfield Limited has float bowl covers and metering pins.  440 786 8141

2.  Old School Antiques. 262 275 6403  Has many of the internal parts

[Hube1iam]

On 12/19/2021 at 4:22 PM, michealbernal said:

You might also try obtaining a copy of the book "Carburation in Relation to Service" by the Marvel Carburetor Co.  I got my copy from Bobs Automobelia.  It has numerous drawing and pictures and explains exactly how to overhaul and set up one of these units.  There are several key measurements  that must be maintained for Marvel Carburetors to operate correctly.    I believe Carb King has parts including gaskets and floats.  
 

I didn’t realize he was a contributor. I did a search and found Carb King. I’m pretty sure I talked with him on the phone a few weeks ago and he was talking 20 weeks or more to get a kit. I’ll try calling again in the new year to confirm though. In the meantime I’ll try some of the other numbers provided. Thank you all.

[Dave39MD]

Carb King can be found here;

 

He answers calls on Monday and Tuesday. You will need your carburetor number when calling.

 

https://www.thecarburetorshop.com/Carbshop_kits.htm

 

Dave

[Gary W]

Don't  rule out a bad condenser.  Those things can cause a bunch of symptoms when they fail.

[Hube1iam]

I just finished a second round of vacuum leak testing and found nothing. The car was converted to a negative ground at some point in time. It starts very easily but I’m wondering if I may have some kind of electrical issue coming from the generator that causes it to shut down then restart. Grabbing at straws here. I’m assuming if I switch back to positive ground the starter will either not operate or will turn backwards. Right now the ammeter registers negative when running but remains steady.

[Oregon Desert model 45]

Buick was always negative ground.  It was Ford that used positive ground.   If the generator is working and  ammeter is registers negative, then swap the wire connections at the ammeter.   Use a multimeter as independent check of generator function.  I found the multimeter very helpful for troubleshooting electrical gremlins, but my cheap Harbor Freight digital multimeter would not measure the generator output on another car of mine because it was too "noisy".  I found an older analog multimeter (cheap one) that worked just fine. 

Kevin 

Edited January 2, 2022 by Oregon Desert model 45
edit (see edit history)

[Oldtech]

Negative ground IS correct, and no, the starter will not run backwards if it's wrong.  Surging is usually carb related but as has been mentioned, a condenser can give you fits. Marvels are special but lots of help on here and can be made to run nice. 

[dibarlaw]

That was what I was thinking on the ammeter. The newer replacement Stewart Warner that was in my car was hooked up opposite of what the original National was. When I replaced with an original National.

 it was showing discharge. National Gage shows carge to the left while the SW shows charge to the right. Switched leads and all was fine.

Edited January 3, 2022 by dibarlaw (see edit history)

[Hube1iam]

Thanks for ruling the grounding issue out. The car has what looks like a regular one wire condenser. I’m assuming any 6 volt condense for an auto supply house will work?. I’ll try that too and then off with the carb. I’d gladly pay to have it redone as I’m a total amateur. It seems like everyone I’ve talked to is telling me months to go through one. Any suggestions there? 

[Robert Engle]

Even if you are going to send it out, I would have to take it apart just to see what's  inside and see if there is anything obvious wrong. In my experience they are fairy easy to take apart and reassemble.  Adjustments are more complex.

 

Bob Engle

[Hubert_25-25]

Can you install a vacuum gauge onto the intake manifold?  What is your reading at idle?  What is your reading at idle when you install a plastic tee so that the vacuum tank is still operating?   

 

Hugh  

[Hube1iam]

I’m not sure about the vacuum gauge. I’ll check later today. I do not have a vacuum tank. The previous owner removed it and installed an electric pump with a Ho hum regulator. The regulator was leaking so I replaced it with a Holley regulator and set it at 1 lb pressure. Nothing I did changed the way it ran.

 

[Fred Rawling]

Do the easy thinngs first. 

 

Thesw carburetors came eith a filter screem ewhere the gas line connects to the carb boiwlk.  Check it.  When you reasemblr  it put some Permaterx #2 on the round gaskets.

 

Check the timing.  If you do not know how to do it,  I will send you copies of the pages in the shop manual

.

Make sure that the flaper in the exhaust manifold valve is open.  The end of the axle for the flaper has a line on it to show the direction of the flaper.  Caution!!  The heat riser plate on the dash is very delicate.  If you use the heat control lever and anything sticks, you will brake that plate (over $100.00 to replace). I leave mine disconnected  behind the dash.

 

Check the condensor.  Put in one for a 73 El Camino.   The car will run fine with it.  

The only caution is that the value is not correct you could erode  the points.  That is probably not going to be a probem if you use it for a test.

 

Spray some WD D 40 or other penetrating oil on the valve strems to be sure that none are stricking.  Watch them.

 

If there is still a prolem, I would check the heat riser tube in the heat riser..

 

If that does not workj, tell us how it runs down the road.

 

Fred 562 644-4670

 

 

 

 

[Hube1iam]

I changed the condense as several have suggested. No difference. We disconnected the electric fuel pump and tried a gravity feed. No difference. We pulled the carb. It will surely need a going over as it seeps fuel even with gravity feed. I finally got up the nerve tackle the heat riser and I got really lucky. The bolts came loose fairly easily. The gaskets between the riser and the exhaust manifold are pretty ratty but seem intact. The is NO plate to block off the riser from the exhaust. The inside of the riser is pretty sooty and as yet I haven’t determined if it is perforated. The butterfly moves freely but does not close completely. Maybe a 1/32” gap.. I haven’t tackled the carb yet. A friend with lots of experience with carbs has it but we’re only looking for obvious things. I’d like to put a plate between the riser and the exhaust manifold but I’m concerned that the thickness of the plate plus the gaskets will throw off the alignment and I won’t be able to button it up tight. Any suggestions on that would be appreciated. That you all for the helpful suggestion.

[Hubert_25-25]

This will guide you thru the carburetor and the heat system blocking.

 

 

[Hube1iam]

Thanks to all of you and especially to Hugh for his detailed carburetor rebuilding tech paper. The heat riser is blocked and the carb is readjusted with just a little honing of the needle valve. It’s back on and purrs like a kitten. Wow.!! It is also obvious that these carbs cannot take even 1 psi directly from an electric fuel pump via a pressure regulator. You can see the fuel blow right past the needle and seat. I’m thinking the best thing to do is to try to acquire a vacuum tank and use the electric pump to supply fuel to the tank and just let the carb draw from the tank as it was designed to do. The only problem is trying to find a vacuum tank. If anyone know of one or has another suggestion I’m all ears. Again thanks to all for your help.

[Hubert_25-25]

Glad things are working out for you.  Vacuum tanks are great when they are set up correctly.  The Master vacuum tank is slightly larger than the Standard vacuum tank.  In the photos, you can barely make out the model number which is 215 for a Buick Standard.  For your Master, it should be a 216 when you are shopping around.   Attached is a photo of a 1926 Master so you can see the size and the fittings that go on top.

 

 I also have a neoprene needle and seat assembly if you want to try it in your carburetor and see if it can handle your fuel pump pressure.  Hugh   

 

[Hube1iam]

Thank you Hugh. Yes I’d like to try the neoprene needle and seat. Please send me your payment info by email. Thanks