Porsche 356 Tune-up Part 3: Tuning Zenith Carburetors!

[@ArnaudShanghai]

Thanks a lot for your help to the 356 community. I will follow your tutorial video to tune up my 1958A Ruby Red. I never thought I could do it by myself, but it actually looks fairly easy.

[@HeidiandFranny]

+ArnaudShanghai let us know how it goes.

[@theaircooledpower]

Hi,how can I get in contact with you please? I have a 356c of a friend of mine and it is making quite a strange thing on idle, don't know how to proceed. Cheers

[@haroldphillips2416]

That was an outstanding lesson, very well demonstrated and precisely performed. Good job!

[@michaelmccormick1745]

Hello Heidi and Franny- as Arnaud said above, we appreciate the time and effort you two put into your videos. They are fun and informative! I am the caretaker and owner of two Ruby Red 356's- a 1960 Cabriolet and a 1962 Coupe. Your KZbin channel helps with maintenance and repairs. I rely heavily on the talk forum of the 356 Registry as well for technical information and tips. Perhaps we will see you at a future Rocky Mountain PCA or 356 Registry event... cheers from Grand Junction, CO (USA).

[@randwintermute4059]

Heidi - fantastic 3 series set of instructions . Love your simple clear presentations ! CMDR Rand Wintermute , USCG ( Ret.) 1956 356A 1600 owner

[@crunchylicenseplates9008]

Your comment at 9:25 about where to start from scratch is the unwritten lore of working with these carbs. Thanks so much. Have to write that down somewhere.

[@HeidiandFranny]

+Crunchy License Plates love your name! Thanks. Heidi

[@michaelstora70]

Another Pinzgauer 712 owner here. One of the clearest instructions on balancing I've seen anywhere. The starting point for the air bleeds is super helpful!

[@HeidiandFranny]

Glad it helped!

[@maralixchamlian1447]

This is one of the best explained & thorough video that I have seen, Great job.

[@theglmyersmusicchannel1814]

These videos are priceless in their clear presentation of "how to" information and detail. Many thanks for posting them, Franny. Keep 'em coming!

[@HeidiandFranny]

Thanks so much!

[@aidanB.]

I've recently discovered, and subscribed, to your channel. Apart from the super useful instructional nature of it, I've been very impressed by your camera and editorial work. Both of your lovely nature's shine through as well. As you can tell, you have a new fan of your channel. lol.

[@HeidiandFranny]

Yea!

[@elcommandante79]

This is helpful for my ‘72 Pinzgauer 710M as well. The twin Zenith 36NDIXs on my truck are virtually identical. I’m so grateful for your help.

[@HeidiandFranny]

You bet!

[@Thrakall]

Informative and concise as always. God that engine compartment you could eat off of it. It's a testament to the care of the car. So satisfying to see this car properly cared for. Thank you!

[@HeidiandFranny]

Thanks Tim! Many hours cleaning that engine! Makes it a lot easier to spot problems ;) F

[@drdennington]

What a great series!! Very very cool!

[@HeidiandFranny]

Thanks! f

[@MX-fo2nu]

Very good and professionel work and tips also helpfull for Type 4 with 2 double weber

[@64atlas]

Excellent Videos! They were extremely helpful for me to reference while tuning up my 356B. The car runs better than ever.

[@ZEZICO1950]

Really love your videos, here from BRAZIL congratulations for you.

[@HeidiandFranny]

+Jose Rodrigues thank you!

[@fishfan0092]

These were very helpful!! I just got a 1969 912, and will be doing all 3 steps!!!

[@HeidiandFranny]

That's awesome Rob! Let me know if you run into anything weird. Do you have Solex carbs? Should be the same basic process. Syncing the carbs really does help to make the engine run smoother - and idle better. Yea! Franny

[@HeidiandFranny]

Hmm, a bit of a drive, but could be fun! Honestly, I think it is pretty much the same. Does your manual step you through it? The 356A manual even has an exploded view of the Zenith carbs! All the stuff about the linkages still applies too. If you are really nervous, just lightly run each of your air bleed screws in and note how may turns. That way if you feel like you have lost your way you can start over. The 912 is really nice. You'll love it! F

[@fishfan0092]

Heidi and Franny's Garage Thanks! Will let you know how it goes!!

[@joewellman7205]

I have a 1974 Pinzgauer with the same two carbs. I was great to see video on balancing them.

[@steffydog]

Fab as always x

[@HeidiandFranny]

+steffydog1 thanks!

[@DILSO56]

I really like this!

[@HeidiandFranny]

+Adilson wonderful. Heidi

[@cleanasdirt6832]

A friend of ours just had a baby over the weekend. She named her Heidi!

[@HeidiandFranny]

+Dwayne Rose interesting. My dad called me Heidi and my mom called me Carrie for the first three days of my life. Dad won. Lol. It's a great name in Europe. It's not as common in the US (or Canada, since I assume that is where she is). It's a fun name. She will get the book Heidi given to her like a bunch of times. Yes, I have seen all versions of the movie. Lol. Heidi.

[@shoulderthelion-film9895]

A few points. When you adjust air or mixture screw - always keep the RPM at your prefered RPM range (say 800-900 in your case). At 1400 where you ended up you might be pulling fuel from other orifices such as your mains so your fuel/air adjustments are not "true." So when you bring your RPM finally down your engine sounds rough because your adjustments were not "true." Best is to keep the RPM on the low side so you are certain that you are adjusting nothing but idle circuitry. Hope it helps!

[@ToughShiftGarage]

you make everything look so easy!!! thanks for the great videos!

[@albapor1]

Hello there ! i've discovered your channel this night when looking for any kind of zenith ndix videos and i got amazed by the look of your airfliters . now you said they were standard but here in France i only find the black airbox wich is way less classy . also flat 4 makes similar ones but with a filter included in the package, have you seen one and does it look as good or does it look cheaper? Also very good video , very professionnal and clean , perfect . You gained a sub for sure !

[@PhilGreeleyJR]

Awesome thank you

[@JudValeski]

One of my air bleeds seems off. Turning it in one direction causes it to drop off peak, but once it gets back up to peak when I return it to the original position, I can turn it seemingly in perpetuity without getting rpms to drop in the other direction.

[@pauldaly3589]

Hi, thanks for your videos, I have looked at many and they are always a help. I‘m so grateful that you take the time and effort to make the videos. I have a 1968 912 project car, engine, carbs etc have been rebuilt (Carbs twice !). I‘m really struggling to tune the carbs (Solex 40 Pll) - I was so frustrated I gave it to my mechanic who also reviewed all the variable ( timing, sparks, valves clearance, checked compression etc) - the car starts from cold with some difficulty, runs fairly well when above 1800 RPM but is lumpy and hesitant during transition from idle. To be honest I cant really find the sweet spot when adjusting the idle mixture, it doesn’t seem to change revs. It could be my lack of experience (why I took it to an experienced mechanic but we are still not where we want to be). Any thoughts ?

[@mohammedalbalooshi7023]

Perfect job

[@carplanetcom]

Excellent video as usual! Just curious if you are planning a video on throttle linkage adjustment? That is one of the most common issues I've seen with all the 356's I've owned. Most of them have needed throttle linkage adjustment in order to obtain full throttle. Many were only getting 50% to 75% of full throttle! There are various "links" in the throttle linkage chain, so lots of points where slop can be introduced. One of the least costly ways to get more horsepower out of your 356.

[@HeidiandFranny]

I did a little bit of this in the Speedster Vlog #5 - A Balancing Act: kzbin.info/www/bejne/Z6izm62sasyErLs But I didn't cover WOT. That was the very first issue with the Spyder. A well sorted 356 is spritely and nimble, quick on the throttle and eager. If not, then there is some digging to be done :)

[@timrichter979]

I like your Honda the most :D Nice video :-)

[@HeidiandFranny]

Tim Richter hope you subbed. We are going to do some DIYs on it very soon. Heidi

[@timrichter979]

Of course :-) I would like to see some more DIY of a VW beetle but the others are very informative too :-) keep it up!

[@HeidiandFranny]

Tim Richter we should have another VW one soon when the weather warms up. Maybe in the next month. Heidi

[@timrichter979]

Niiiiiice

[@jamestharp7880]

Hi Franny, Is there a specific number or type for the K&N air cleaner foam? I really enjoy your instructional videos. I will be coming out to Colorado end of August beginning of September to hike up some big hills. Will you be doing any 356 live events during that time?

[@HeidiandFranny]

Hi James, It is just open-cell foam in a roll and I cut it to size... Should be able to find it at your FLAPS. With the COVID thing we are laying low...

[@pinzgauernorcal]

thanks

[@bolti1000]

Grannies, great video - as always thoroughly enjoyed it here in the UK. Any chance you could do the same for twin choke Weber’s?

[@HeidiandFranny]

Don’t know of any friends with Webers and we are not grannies. Not yet. Not even retired.

[@jens6021]

Hi Franny, thank you so much for these great instructions again! I watch your videos for a couple of consecutive evenings now, and really love it! However, I tried to set the carburetors of my 356 SC from 1964, but the idle is unstable in itself, so its impossible to adjust the carburetors with the air bleeds. I wonder if you have a hint, what the reason could be for the idle going up and down... Many thanks!

[@EastOfOctober]

Thank you, thank you, thank you!!!!!!

[@HeidiandFranny]

Hi Ed!

[@HeidiandFranny]

You bet Ed! How did it go? F

[@EastOfOctober]

I've ordered a Uni-Syn Carburetor Synchronizer/Carb Synchronizing/Balancing Tool. When I need to tune up my carbs, this video will be my go to resource. Love you two so much, thanks for all the great videos!

[@rparker2824]

Thank you!

[@RoeVenturesLLC]

Awesome very informative

[@HeidiandFranny]

Yea! Thanks! Franny

[@freerkderuiter8822]

Great video! Most 356's I come across don't have the original air filters on them. Did you find any difference in performance with the K&N foam inserts?

[@HeidiandFranny]

Those air cleaners really Set off the original look! As to performance, no, not at all... They are pretty low resistance. Since the car is old-skool, the carbs will enjoy the small bit of oil from them. If the car had a hot-filament mass air flow sensor, these inserts would trash it pretty quickly ;) I have had others express concerns over possible carb fires, but the metal Kinects should be sprayed with oil after cleaning as well, so I really don't see the difference. The carbs to pop (pre-fire) a bit when cold (a sign of running lean), but the best thing to do is kick up the idle a bit to draw that back into the carbs and into the engine. I have never had any issues with that at all. It is hard to ignite oil ;) Franny

[@conceptalfa]

👍 👍 👍!!!

[@allanbrz9602]

Muito legal :)

[@HeidiandFranny]

+Allan Brasz muito abrigada. Heidi

[@herlinwoolery4388]

Thank you for this nice learning video ,I have noticed that the carbs are on a fiber type block is that for better insulating from Heat?. Herlin Woolery

[@HeidiandFranny]

Hi Herlin, Yup... That is the idea/hope. With those short intake stacks the carbs can percolate about 45min after a good run. I was having carb weeping issues and that did help. The kit comes with longer studs and you need two carb gaskets. Thanks! Franny

[@unitedfidosc]

do you have a video for rebuilt and setting the gas level in the carburetor bow of the Zenith carburetors? Thx

[@HeidiandFranny]

We do not. :(.

[@unitedfidosc]

:( :( Hopefully you can do one soon. Thx

[@unitedfidosc]

do you clean the idle jet if the carburetor doesn't response to the mixture screw?

[@yoshitofunakoshi7720]

Is this the same if you have a zenith in an aircooled 1641 vw bug?

[@HeidiandFranny]

If the carb(s) are the same then yes outside of the specifics of the linkage. But, the steps are the same.

[@fgjf1079]

When I pulled the plugs on my 912, I noticed that the gap on plug #3 was almost fully closed up. Is that a sign of cyl 3 running too lean(and running hotter)? In other words, does excessive heat cause plug gaps to close?

[@HeidiandFranny]

I would guess it got hit while it was being installed. There isn't a way for the gap to get smaller while running. Usually they start to erode effectively widening the gap. It is very easy to donk the end of the plug when trying to get it into the hole...

[@RichieRich845]

Hi Franny, would a petrol leak cause the same symptoms as an air leak? I have been trying for days to tune my webers (double) and I couldn't stop it from spitting at me from the carbs, the only way to stop it was adjusting the idle mixture screw 14 half turns and even then it would spit at me about 2500 rpm, idle was still rough. Then I noticed that the fuel regulator (with glass bowl under it for the petrol filter) was leaking petrol at one of the pipes from the regulator (the hose goes from the mechanical pump to regulator. Car is Alfa Romeo 2000 Spider 1974. I have ordered another one and should arrive tomorrow. I noticed how responsive your idle mixture is on your car, I hope after I replace the regulator my mixture screws would be responsive too. Thanks for another great video. Rich

[@HeidiandFranny]

Hi Rich, a leaky fuel line won't do that (but is super dangerous). Those air bleed screws should be pretty responsive. If not, you probably have some crud making the adjustment for you. If the carbs have sat for a while, there is a good chance they have some varnish blocking some of the pathways. Bull those bleed screws and shoot some carb spray into the hole and any other holes in there you can see down the throat. If that doesn't do it, you may need to pull them and do a thorough cleaning (pull them apart and such). Let me know how it goes. Franny

[@RichieRich845]

Hi Franny, thanks for the advise, after replacing the regulator it was much easier to tune, I have cleaned the carbs and the needle valves (idle mixture screws) and new orings on the cup washers under the springs of the adjusting idle mixture screws. Still not as responsive as yours but I managed to tune them to stop them from spitting and I also Advanced the dizzy from 4 to 12 degrees BTDC. Still the engine seem to be rocking on Idle, it drives OK so I took it for a 300 KM drive, it spat sometimes at 2500 rpm at 80km/h, but it was a great drive. I will take to a Carburetor Service and have look at it. Thanks for responding. kzbin.info/www/bejne/hJ_PfaKEq8xjeck

[@RichieRich845]

Fixed. Hi Franny, After watching your VW Fuel pump replacement, I decided to buy a Fuel Pressure Gauge to test my fuel pressure. At idle the pressure was 6 PSI, the replacement original fuel regulator did not have much of an adjustment as the original pump didn't put out much pressure compared to the after market pump. I ordered a Filter King Regulator which looks like my original but bigger. I lowered the PSI to the correct pressure for my car 3 PSI at idle and tuned the carbs and it worked great, also adjusted the timing to 13 degrees BTDC. The engine is now smooth and much quieter and responsive. Thanks for posting that video. Thanks.