WEBER 40 - 914-6 or 911T Carbs, They seem to be the correct carbs but not stock? Options

[brant]

I don’t know what stoddard was doing

Assume they were increasing vents from stock to improve the top end


But like Mark posted.
I run IDS carbs on the race car for higher rpm fuel enrichment (jetting)
They have an extra passage to feed an aux enrichment tube at high rpm

Believe that carb was only made for 2 years

[mate914]

I had Paul Abbot(sp) convert a set of carbs to IDS.
Matt

I don’t know what stoddard was doing

Assume they were increasing vents from stock to improve the top end


But like Mark posted.
I run IDS carbs on the race car for higher rpm fuel enrichment (jetting)
They have an extra passage to feed an aux enrichment tube at high rpm

Believe that carb was only made for 2 years

[brant]

I had Paul Abbot(sp) convert a set of carbs to IDS.
Matt

I don’t know what stoddard was doing

Assume they were increasing vents from stock to improve the top end


But like Mark posted.
I run IDS carbs on the race car for higher rpm fuel enrichment (jetting)
They have an extra passage to feed an aux enrichment tube at high rpm

Believe that carb was only made for 2 years

They work so well for high rpm
I can see the AFR go lean at 5k, then fatten up all the way to redline in real time on the track

[ctc911ctc]

****UPDATE****

Sooooo.......it would seem that one of the previous owners had the carbs sent-out for rebuilding and there was either a swap of the originals were treated as a core and replaced with PMO carbs.....

Out of curiosity I found a set of 914-6/911T carbs that are originals, completely re-refreshed and rebuilt. Asking Price? $10k+ - YOW........Very interesting but not for me right now.

I received no feedback as to the state of the carbs so here is the plan

1. Static Calibrate the floats
2. Dynamic (with the sight-glass method) calibrate once I can hook the fuel pump up to them.
3. Each of the two calibration screws in each of the carbs to their factory presets.
4. Start Car
5. Go through the tuning as shown in this video

https://www.youtube.com/watch?v=p3qwIbRdcvE&t=60s

Any Suggestions?

Thank you Teeners...

[rgalla9146]

Those are replacement newer production carbs.
The previous owner (to me) was in failing health.
I suspect his wife had a local shop replace the carbs so he might be able to drive it.
It was dormant for more than 15 years plus another five in my posession
As a side note, I see it has larger venturies (stock were 27mm)
I'd check all the other changable 'adjustment' parts and compare to stock.
Rory

[mskala]

You can borrow my float level gauge and I have some random jets and emulsion tubes
that are at least reasonable for 2.0 - 2.2L engines.

Also when everything is running you need to set the idle airflow, I have the choke air meter.

[Graydingo]

Yeah those aren't PMO, Carter was making those repops in the US in the 90s. You can always tell by the silver finish and the rough outer casting compared to the greener metal of the Italian webers.

Richard Parr, PMO, made a somewhat different carb design that has now been bought out by EMPI. PMO are easy to identify as they have a fuel window in the float bowl (It's a big brass nut)

Nothing wrong with these carbs you have. Probably better that they are only 35 years old as opposed to 60 or 70.

Enjoy your journey getting these to run right. Be patient. It takes a lot of reading and fiddling.

[DennisV]

Are 914-6 carbs NOT market like 911 carbs are???????

I went down this rabbit hole when I took the Zenith carbs off our 914-6 engine. Here's what I found:

The 914-6 part number adds a “1” after IDTP, whereas the 911T does not. So

914-6 70-76
40 IDTP 13 C1 – 901.108.115.00
40 IDTP 13 C – 901.108.126.01

911T 69-
40 IDTP 3 C1 (left 911) – 901.108.118.01
40 IDTP 3 C (right 911) – 901.108.118.01
The distinctions, like the model number, are quite subtle.

The Webers themselves look identical from IDTP to IDTP1, the only real difference is the location of the main fuel jet installation. The main fuel jet location for the middle barrel is towards the front of the car so for 914/6 the location of the main fuel jet is relocated from that of the 911, nothing more that that and a part number difference.

Paul Abbot from Performance Oriented

[sixnotfour]

Yeah those aren't PMO, Carter was making those repops in the US in the 90s. You can always tell by the silver finish and the rough outer casting compared to the greener metal of the Italian webers.

Richard Parr, PMO, made a somewhat different carb design that has now been bought out by EMPI. PMO are easy to identify as they have a fuel window in the float bowl (It's a big brass nut)

Nothing wrong with these carbs you have. Probably better that they are only 35 years old as opposed to 60 or 70.

Enjoy your journey getting these to run right. Be patient. It takes a lot of reading and fiddling.

Richard Parr Sold 1000s of the Carter webers,,that's why people get confused when stating PMO carbs .. His redesigned Weber style carbs are the lastest ,,go around .labeld PMO.. sold company now EMPI... So PMOs should be EMPI PMO Weber style carbs... as of today...

[sixnotfour]

"S" is Best..

[sixaddict]

Just an FYI
I have a set of original set of 914-6 carbs that have been completely rebuilt (to stock configuration) including shaft bearings etc. many new parts as they had been significantly cannabilized.
Have complete list of all new parts. Looking for $2500.
If any interest, pm me contact and I will send pics and more information.

[sixnotfour]

He has it handled Im just messin around...

[sixnotfour]

(IMG:style_emoticons/default/beerchug.gif)

[ctc911ctc]

[ctc911ctc]

(IMG:style_emoticons/default/icon_bump.gif)

[ctc911ctc]

SORRRY - pictures are in the Preview but not in the post (IMG:style_emoticons/default/WTF.gif)



I over analyze everything!

Over-Analysis working theory

If you are reading this you are up to speed as to what I am chasing.

I cannot get the car to start when cold (60 degrees F or hotter) without 10-15 tries.

Each try is the same.

Idle handle - full ON
PUMP the gas peddle twice
Grind the starter
Pump the accelerator
Engine immediately starts and then dies.
Repeat 10-15 times
Then engine will start to stay running
Once it is warm and starting it is running smooth, occasional pop and also Smells VERY rich, VERY, VERY rich

This makes little sense too rich and I need to pump it to get it started?

Perhaps the downflow of the carbs (veturi effect) is so weak that I need to keep the fuel pumping from the accel-pump circuit since the jets are not supplying the fuel?

NEXT

Looking at the spark plugs, I see that one side is VERY rich, the other is not.

IDEA

Perhaps once side the carb is working properly (RICH) and the other is running LEAN and the leanness or fuel starvation is causing this hard to keep started effect?

Plugs 1->6, L->R

[930cabman]

One side very rich should provide a clue to what's going on, but could be multiple issues

When warm how does she start/run and the color of the plugs

Float levels ok? needle valve sealing ok?

these can be buggers until they give up their secrets

[ctc911ctc]

Fixed the pictures within the last post - BUMP

[Superhawk996]

www.914world.com/bbs2/index.php?showtopic=376092&st=20

Post 33 (carbs are not tuned properly - all plugs are rich. There are no lean plugs)

@ctc911ctc

Easier to keep history if not bouncing between multiple threads

Cold start always needs to be richer to start. This is true whether carbureted or fuel injected.

Every carbureted car is slightly different on how it prefers to be started but having the fast idle lever on when trying to start isn’t likely to be helping. At cold start it is usually more effective to have throttle plates fully closed. The fast idle lever is cracking them open.

Similarly in the owners manual for cold start you won’t see any reference to use of the idle lever

Regardless of all this your carbs aren’t tuned properly and all cylinders are rich.

Bottom line; carbs aren’t tuned properly.

[73-914]

China now making replacement carbs.

(IMG:style_emoticons/default/lol-2.gif) (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/stirthepot.gif)