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FIXED!! : Drippy Carbs, poor runnning
Posted by: keitho64 ()
Date: September 06, 2018 08:17PM

Hello everyone,

I have been troubleshooting intermittent carb issues for a long time. Quick background it is a 1964 110hp with the Otto 4X1 conversion running four primary carbs from a 64.

It is running an electric fuel pump with a regulator set to 4psi.

I’ve rebuilt the carbs quite a few times and am running the clarks ball style needle & seat. I’ve checked the body for warpage and it is all true. I’ve checked the float level multiple times and the floats have the spring installed to add pressure to the needle & seat.

What happens is the car will start to run like crap, hard start when hot and smells of gas when hot. I can look down the carbs at idle and see fuel dripping into the Venturi. When I shut the car off gas will pour into the base of the carb, leaking into the manifold and thus flooding out the engine. This is only happening on two of the 4 carbs. For now I blocked off the two that leak and the car runs perfect. However I would like to get back to 4.

I am assuming the floats must be leaking and sinking in the bowls but when they get hot. This is only an assumption since it acts like a float level that is too high. However when I check them off the car there is no sign they are leaking.

The only other idea I have is the parts are mis-matched to the carbs. I had numerous carbs and parts so it is possible they are not correct. I have Bob Helt’s book and it looks correct.

So the two questions I have are:

Can anyone think of anything I am missing? I feel like I am reasonable adept at this but I must be missing something.

Does anyone have a pair of complete carbs they don’t need and want to sell? I’d like the 64 style or the later with the power enrichment circuit. If so let me know.

I am in the Chicago area but carbs are small enough to ship.

Thanks everyone!

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles



Edited 2 time(s). Last edit at 09/14/2018 10:47PM by MattNall.

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: MattNall ()
Date: September 06, 2018 08:21PM

Kieth... old Regulator that has gone bad... Get aHolley with return line port and add the return.... only needs to be 3/16" line..





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: keitho64 ()
Date: September 06, 2018 08:30PM

Matt,

Thanks, the regulator is new, I had an extra one here. It is a dead head style without a return. I can try one with a return line but will need to plumb that in.

Have you run a return line before? If so where is the best place to mount the return line to the tank? In the fuel filler neck?

Thank you,

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: dryenko ()
Date: September 06, 2018 08:40PM

Have you thought of installing a fuel pressure gauge or a low pressure pump?
The ball seat float valves can tolerate up to 7 psi, but if a street car 3-4 psi should work just fine.
And I have carbs, PM me for more info.
Bob C

Bob C aka Dryenko
Dobson, NC 27017

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: 63turbo ()
Date: September 06, 2018 08:52PM

Not sure if this is helpful, but when I used the all metal (ball type) float valve (on the Carter YH), I remember the recommended float height settings for that valve were quite a bit different than the standard settings. Although I don't remember the numbers, the "idea" behind the different settings was to have the float lower in the bowel when the valve is closed, creating more force on the valve, and hopefully better control of the fuel level at elevated fuel pressures. The addition of the all metal (ball type) valve and the modified float level settings sure seemed like a miraculous flood cure for the
YH- I'm wondering if the float level settings for that valve you used are different than the stock settings... if you used the stock settings, perhaps it might be worth trying a lower float height, to push on the valve a bit harder. When I ditched the YH in favor of a 45dcoe weber for a lot more power,
I ran a Holley non return type fuel pressure regulator, and set it at 2.5 psi, and left it alone.... it worked completely and totally fine!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: keitho64 ()
Date: September 06, 2018 09:02PM

Kevin
You may be on to something. I set them at a stock setting. I’ll lower it and try.

Bob
Thanks, I’ll send you a message.

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: TerribleTed ()
Date: September 06, 2018 09:37PM

what float level are you setting? Set them at the stock 1 13/64's of an inch or just a little more (I always set 1 7/32's). Reduce the fuel pressure to more like 3 psi...4 is a little high. See if that helps.

---------------------------------------------------------------------------------------------------------

Avid Corvair hobbiest since 1984.
I have personally performed ground up restoration on over 20 Corvairs.
I currently work full time at restoring and repairing Corvairs.
Located in the Atlanta Georgia area.
[www.facebook.com]

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: MattNall ()
Date: September 06, 2018 09:43PM

keitho64 Wrote:
-------------------------------------------------------
> Matt,
>
> Thanks, the regulator is new, I had an extra one
> here. It is a dead head style without a return.
> I can try one with a return line but will need to
> plumb that in.
>
> Have you run a return line before? If so where is
> the best place to mount the return line to the
> tank? In the fuel filler neck?
============================================

Not on a Vair, but several others...

Is you reulator in the engine bay? Just run back to the Rubber line at LRW. You are not having a TEMP issue.. so this will be fine.





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo




Edited 1 time(s). Last edit at 09/06/2018 09:44PM by MattNall.

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: JimBrandberg ()
Date: September 07, 2018 04:35AM

Sometimes carbs that drip from the venturi cluster arms when running are due to the gasket surface on the venturi cluster. As per a thread on this forum, I made a tool from a needle nose pliers for removing the tubes, then sand flat with a piece of emery on flat surface. The previous thread has nice pictures and everything.

How does the fuel level look in the bowls look when you take the tops off? This may be a better indicator than what the measurement is with a ruler.

Not everyone has good results with grose inlets. Some folks love them, others not so much.

I have some trouble with drippy carbs and it can be very frustrating. Some times nothing seems to work and everything checks out okay with repeated disassembly and checking. I'll certainly be watching for some pearls of wisdom.

Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: BobV66Vair ()
Date: September 07, 2018 06:24AM

Keith, I had this exact problem on my car. 4 one-barrels and electric pump. I do not have a regulator but the pump is supposed to be factory set at 4 PSI. I went all over trying to stop one carb from dripping. My last attempt was to replace the cluster. While I had the carb on the bench, I decided to run the cluster screws down without any gasket. I found that the screws did not hold it tight. There was a small wiggle. I saw a lot of gunk on the screws so I replaced them. That allowed the cluster to get tight. I put the gasket back in and tightened it up. I also decided, at Steve Goodmans suggestion, to change the float level so the bowl would not get as full. I had noticed that when I pulled the top off the carb that it was VERY full. I changed the float level to 1-5/16" and made sure they were totally level with each other and with the gasket surface. That means that they provide as much force as possible on the valve. I am not sure which solved my problem but there is no longer a leak. Car, finally, runs well. I do have the vents on the base of the carb and that helps with overheating. You might make sure your are working as designed.

Bob Vinnacombe
Sandy, Oregon
1965 Corsa 140 stock
1966 Monza Soon to be race car
1968 Monza Parts for now

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: corventure Dave ()
Date: September 07, 2018 07:38AM

I recently found that even the NOS carburetors I installed had less than flat cluster surfaces.

Corventure Dave

Attachments:


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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: keitho64 ()
Date: September 07, 2018 09:24AM

Thank you all for the tips. Since the problem seems to be isolated the the two carbs I will pull them apart this weekend and check.

1 - Install venturi cluster without gasket to see if they tighten up
2 - Check venturi for level by removing tubes and using find sand paper on a flat (glass) surface. I have a piece of glass I use to check carb bodies. If bad smooth them out.
3 - Lower float level to 1 5/16
4 - Drop fuel pressure to 3.5

I appreciate all the excellent advice, this is exactly what I was looking for.

I'll work on it this weekend and report back.

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: steve c goodman ()
Date: September 07, 2018 09:42AM

Keith watch the position of the mixer tube (tube with holes in it) when you remove it. There is a pickup hole near the very top of the tube which must be in the proper position.

Good luck.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: 66vairman ()
Date: September 07, 2018 09:52AM

Jim, Bob, Dave made good comments.

Sometime back a fellow posted that he had trouble with the "ball" check valves and upon examination he found small machining burrs that were causing some not to seat.

I've had a few carbs "dribble" and lowering the fuel level by 1/16" per Bob Helts Rochester book usually fixed the issue.

Bob H. did mention that some of the newer float springs (64 and later) have too much tension and I did find this issue with some new springs.

Do check the floats. Often they get bent out of alignment - you have to make sure each side is even with the other and they don't bind on the float bowl surfaces.

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: MonzaJPD61 ()
Date: September 08, 2018 01:48PM

For what it's worth, after trying many different setups, I have had the best success with float level control and shutoff using the correct inside diameter inlet for my '61 98 HP and the all metal needle (no rubber tip).

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: keitho64 ()
Date: September 08, 2018 05:21PM

JimBrandberg Wrote:
-------------------------------------------------------
> Sometimes carbs that drip from the venturi cluster
> arms when running are due to the gasket surface on
> the venturi cluster. As per a thread on this
> forum, I made a tool from a needle nose pliers for
> removing the tubes, then sand flat with a piece of
> emery on flat surface. The previous thread has
> nice pictures and everything.
>
>
>
> Jim Brandberg
> Isanti, MN
> CorvairRepair.com

I’ve been trying to find the thread on Venturi tube removal for reference but can’t locate it. Does anyone have a link to it?


Thank you

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: JimBrandberg ()
Date: September 10, 2018 06:04AM

I searched and couldn't find it either. I thought it was about a year ago. It was excellent with pictures of the sanding process and also the tool needed to remove the tubes. It seems like it was "corventure Dave" as the picture above was similar but I don't know. I made a similar tool by drilling out a needle nose sideways with 2 holes using a very extensive set of letter drill bits.

Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: corventure Dave ()
Date: September 10, 2018 07:33AM

Look at "
Often overlooked on Carb rebuild" post.

Yeo it was me!smiling smileysmileys with beer

Corventure Dave

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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: Wagon Master ()
Date: September 10, 2018 08:26AM


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Re: Drippy Carbs, poor runnning looking for help and want to buy a pair of carbs
Posted by: JimBrandberg ()
Date: September 10, 2018 08:58AM

That's it. I thought it was about a year ago, that post was over 3 years ago. Perhaps someone referenced it again last year...

Jim Brandberg
Isanti, MN
CorvairRepair.com




Edited 1 time(s). Last edit at 09/10/2018 09:12AM by MattNall.

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