Hey fellow 914ers!

So the short version of this question is: My 914 with a 911 3.0 SC engine has sat in my garage for last 8 years. Should I have the Webers professional rebuilt or replace with PMOs?

Longer version;

My 914 has sat in my garage for last 20 years. I had gotten the engine out rebuilt done about 8 years ago and tried to clean/rebuild the Webers (40 IDA 3C) myself. I thought I did a fairly descent job at the cleaning; letting them soak in carb cleaner, clearing out all the lines/holes, replacing the jets, etc. Yet no amount of tuning could I get those Webers to balance properly.

I think I shot myself in the foot at the onset by not replacing the gas tank completely. I had cleaned it out as best I could but it had a lot of gunk/varnish in it but it was never "clean". I am not making that same mistake twice so already have a replacement tank ready. Along with new lines and filter/pump.

It should also be noted that I am not a person like my father who I inherited the 914 from that loved to tinker at the back of the 914 after every drive. I am a more "get it running and work on it once a month or when it breaks" type mechanic.

I've heard a lot of good stuff about PMOs and them not being as finicky as the Webers. I would prefer to maybe set the carbs once or maybe twice a year (if that) but I live in Texas and would like to drive the 914 in the summer time and I don't want to spend hours in 104 degree temps trying to keep the engine from popping and farting all the time.

So should I get my Webers professionally rebuilt or should I go with a brand new set of PMOs? Looking to you Porsche experts for advice!

Thank you in advance!

Peter

Carbs are carbs. Jets will plug just as easily on PMOs.

However, you may have been fighting Weber’s with worn out throttle bushings or butterfly plates that were out of alignment.

So from that standpoint new PMOs will be better. Also new Webers are now available so there is that. PMO now owned by EMPI so I’m not sure how their quality is vs. old PMOs.

How can you possibly let a 914 with a 3.0 sit? Yes, life can get in the way

We are getting a fresh 2.7 ready, hopefully installing soon and are going with 40 IDP Webers. From what I know the PMO's are not the inexpensive way to go

It's a good chance the throttle bushings are loose

Have similar 79 SC 3.0 Motor

Mine came with Webers in a project and I had them rebuilt by Paul Abbot who unfortunately retired.

He was a Weber guru with uncompromising quality. When he was done I literally put them on the car it it ran first time. A-frickin-maziig! It was worth every penny. There have to be more like him out there. Paul had a test bed to set the carbs up on and dial them in, then drain, and ship ready to run.

IMHO if you already own them I'd have them redone. They are Iconic carbs and when set up correctly are awesome.

Good luck
Feel free to reach out via PM if you want more insight

I will say this. Number one Welcome to 914world

Next let me say that Carbs by Webber or PMOs will get clogged just from sitting. I have a Fresh 3.0 with 3.2 big vale heads that was built with new PMO 46s and they would be fine and just from sitting they would clog and be very hard to start. I had PMB Performance put in Modern EFI and it starts right up in just a quick turn of the starter. This is not a bull, it just lights right up.

It is true that old carbs can get to much clearance in the butterfly’s and I remember back in the early 80s going to Bieker Engineering. And Harry Bieker would show me how he would re-Bush them. He was a prominent. carburetor rebuilder in the United States.

It would cost you a lot of money for new PMOs You could think of putting on a new EFI

Look at my blog on my 6 build. It will give you some idea on what I am saying.

Bob B Burton

We like Webers for the simple fact that parts are available from many sources. PMO is just available from PMO.

Old Porsche’s and Weber’s. I got some 40’s in 1982 and this rebuild will be the first. I did get used to pulling the jets and cleaning them after it was parked a bit. I would rebuild them. If life is good the new EFI systems with the throttle bodies that look like the old Weber’s are very cool. And can maintain that old look. Sounds like a fun car

Thanks everyone for the welcomes!

Yes my 914 has been sitting for far too long. I am finally at a place in life where I can devote the time to getting her running again and truth be told, I've gotten my greasy hands habit back.

I like the idea of sending off the Webers to get them professionally rebuilt, anyone have any recommendations?

Also this intrigues me...


I just looked those up. I did not know about them. Besides the kit, is there anything else required? I'd imagine a higher pressure fuel pump would be one and probably an ECU? I like the idea of these because it seems like it would simplify my setup and potentially make it more reliable... anyone have hints/links on going from carb to EFI?

Plus I am not looking to build a speed demon. I already have a 2012 911 Turbo 6MT. I really really don't need any more speed.

I like the idea of sending off the Webers to get them professionally rebuilt, anyone have any recommendations?


None. Like posted if you want to have a realiable engine and if you aren't driving it reguallary it may remain an idea.

I'd go with EFI. PMB would be my recommendation. Eric's will do carbs but I wouldn't want to maintain them unless you have the ability to tune them and maintain them.

Sending your carbs to someone like Paul Abbott (Performance Oriented) will be the cheapest option between the two, even buying a used set of PMO. There are 1 or 2 sets on there now for less than EMPI is selling and I think 1 set is brand new in the box from when Richard still owned PMO.

From a working standpoint PMOs have a creature features that Webers lack, like the sight glass to adjust the floats. You can see from the outside without an additional tool if your floats are right. Cleaning out the fuel passages can be done with a screwdriver instead of pulling a lead plug. You also get the benefit of tuning the idle air jet (Paul has an upgrade for Webers to do this). As far as performance if you take both sets NIB they will perform equally the same. There is no performance boost with PMOs.

I want to say Paul charges around ~$2000 to do a full rebuild on Webers, but his work is art.

As with any dual carb setup you will either need an competent expert in dual weber carburetors mechanic or the tools and patience to understand them. I have been working with dual carbs for many years now and I am far from an expert, but am pretty knowledgeable.

What kind of balancing issues are you experiencing?

If you're in DFW, stop in and see Mayo Performance. It's been a while, but if Ed is still there, I'm sure he can do your carbs.

If the decision is buy new, I would go EFI. I did it on my 3 liter track car this winter and it's awesome. I can no longer joke that if you can start it, you can drive it. Hit the starter button and it purrs. No throttle, no pumping, nothing. Hit the button, listen to it run and idle.

Thanks for the replies and wisdom ya'll. Much appreciated!

I'm leaning towards determining the cost of moving to EFI and then sell the Webers. (I also have an old set of Zeniths as well that came from a 72 Targa.

When it came to getting the engine re-running previously, I could get the Webers balanced at idle but then either after driving around block or after the engine warmed up, would just go to pot. Like wouldn't idle, pops, and the engine lagged in mid RPMs after driving for a bit.

There were a lot of things that probably hampered me the first time. #1 being I didn't start with completely cleaned fuel system and #2 doing the Weber rebuild myself, and #3 I was way out of my depth for tuning Webers.

So again thank you all for advice and guidance!

Attached is current photo and will probably be asking a lot more question from you experts as I go forward with my re-road! Thank you.

Click to view attachment

Eurometrix is another carb rebuild option:

https://eurometrix.ws/

Dave Cheney at DC Carburetor Restoration can restore your Webers. I suspect it won't be inexpensive, but it'll still be cheaper than new PMO's or any kind of EFI.
If the motor is otherwise stock, I would think the simplest and most trouble free route would be the factory CIS....