PMO carbs overhall or rebuild steps or tutorial?

[andy s]

Hey all,

Just picked up a 75 911 with a stock 3.6 with 50mm PMO carbs (and headers). The car had been sitting for a bit. I think the carbs need some work, as it takes repeated 5 pumps and feathering to start, its flat as Texas from idle on up and its spitting up a bit at idle.

Additonally one of the float windows shows fuel 3/4 of the way up the window, while the others are near 20%.

I did check spark and timing (its got msd boxes) and that is good.

I see a bunch of threads on tuning the PMO's but I don't see a thread or tutorial on the proper steps to take off and fully clean them and get to a baseline.

Not sure if there is a specific method or way, but I thought I would check here and see if anyone has created or knows of a step by step to make sure I get it done right, the first time

Thanks!

[911pcars]

Google is your friend:

PMO Porsche 911 Carburetion - Installation

[andy s]

Thanks Pcars, but that is for setting up PMO's... I'm looking for something that address having carbs on a car that need a rebuild and what steps happen when etc, but Thanks for this!

[Gordo2]

Here's some info that may help:

Performance Oriented

Gordo's PMO Carb Tuning

Most info related to Weber IDA's applies to the PMO's, however rebuild of old Webers is far beyond what would be required of your PMO's.

I'm sure your PMO's are still solid / without wear, unlike old Webers that may have worn shafts etc. requiring a no-kidding rebuild.

At most, for your carbs, I would consider removing, disassembling and giving them a thorough cleaning, replacing a few gaskets & possibly new float needles and adjusting the float levels.

Good luck,

Gordo

[RWebb]

why not contact Richard Parr?

you FAX him, and he will call you back

[Quickstep192]

I have about 10% of the knowledge of most of the people here, so this is a rookie’s view.

I had similar issues when I first got my car which has Webers. You basically take the carbs all apart, clean everything with carb cleaner and put them back together. If you get into trouble, someone here will help. There are some expendable parts like o-rings and copper washers that will need to be replaced. They should be available from PMO.

When I did mine the first time, I did it with the carbs in the car because I didn’t want to muck with the linkage.

To me, adjusting the floats was the biggest pain because it’s messy and it’s a trial and error thing.

No matter what you do, you’re going to need to go through the adjustment process when you get it all back together. You’ll need a synchrometer for that.

[Jack Stands]

With today’s fuels, it’s not uncommon for the internal passages and jets to get clogged. Cleaning and replacing gaskets should help. I’d also recommend reading the info that Paul Abbot has provided on the Performance Oriented website before beginning.

[Ryan H]

Originally Posted by RWebb

why not contact Richard Parr?

you FAX him, and he will call you back

That's awesome.