carb questions/options?

911-m5 · 11-07-2004, 07:17 AM

Hi all,

I just got my car back on the road after a 1 1/2 year rest. I have been driving it for a week and it is broken again.

It started sputtering and backfiring on friday, so I pulled over and had a look. I discovered that my carbs were leaking fuel out of where the plunger rods (?) - the small metal rods that are actuated by the linkage that plunge into the sides of the carbs with the little rubber boots around them. They are the stock Zeniths and I know they have been rebuilt at least once and I'd bet they have been rebuilt at least twice.

That being said, I think I am looking at replacing them rather than trying to rebuild them. Unless somebody convinces me that they can be rebuilt again. However, seeing as I just spent $2500.00 to get my car back on the road, I'm not exactly jumping for joy at the thought of dumping at least another $1000.00 into it.

I know I have three brands to pick from if I buy - Zenith, Weber, PMO. Are the PMOs that much better? And yes I am worried about buying carbs with worn shafts. If you were going to buy Webers or Zeniths where would you get them?

Thanks,
Allan

911-m5 · 11-07-2004, 07:18 AM

Oh yeah, and at the moment, I'm only making $8.00 an hour. Sad but so rediculous it's somewhat amusing.

jluetjen · jluetjen's Garage

Where were the Zeniths rebuilt?

911-m5 · 11-07-2004, 07:41 AM

I have only had the car two years. It spent almost all of its life in California. I dont have the records here - they are in the garage about 30 minutes from here.

911-m5 · 11-07-2004, 11:19 AM

bump

RoninLB · 11-07-2004, 11:36 AM

Some pelicanheads can help with the Zeniths. They say they can be rebuilt to very nice condition. I guess a pro rebuild with the shaft sealing may be over $1,000. I think the key here is the condition of your throttle shafts for your options on what you have to do.

It seems like good used Weber 40s are going for $1,500. I haven't seen or heard of used PMOs for sale. New PMos ++ will cost around $3,000

red-beard · red-beard's Garage

The engine builder I use in San Diego also restores carbs. He will not just throw a rebuild kit in. He will re-bush the linkages and make sure everything is tight. I am not exactly sure the cost, but I expect it is only a few hundred plus shipping.

Motor works on Island. Ask for Sergio.

Halm · 11-07-2004, 02:16 PM

Class act: http://www.eurometrix.ws/

Not sure if Matt does Zenith's but worth a call.

project 911 · project 911's Garage

I'm running Zenith's. They took a long time to dial in, but they've been working fine all summer. From your description, it sounds like you are talking about the accelerator pump diaphrams (three on each carb). If these are leaking, then they must be damaged or the mounting screws are loose. My main throttle shafts have some slop in them, but it still runs fine. Those rubber diaphrams should have been replaced in a rebuild.

911-m5 · 11-07-2004, 04:19 PM

I haven't gotten a chance to take them off yet and have a closer look. I am going to try tomorrow afternoon.

jluetjen · jluetjen's Garage

Before you toss the Zeniths it might be worthwhile to look at who did the rebuild. I've seen a few places advertize Zenith rebuilds agressively, but who have a wide range of reputations. A poor rebuild is hardly unrecoverable as long as the bodies haven't been messed up. If the bodies are OK and the shafts are tight, you can do a rebuild yourself in a few hours for about $100 or less. If you want to switch to used Webers the price can be upwards to 10X that price, and there is no guarantee that they will be in any better shape.

911-m5 · 11-08-2004, 08:18 PM

O.K. I got them off and they are apart. How do I tell if they are rebuildable or should I take them to somebody who can tell me?

red-beard · red-beard's Garage

With the additional information, where is the leak? Is it the throttle butterfly shaft bushing area, or is it on the side?

911-m5 · 11-09-2004, 09:54 AM

It is on the side where the accelerator pumps(?) are? The three little square boots on the sides.

Randy Webb · 11-09-2004, 11:16 AM

PMOs are the most advanced design out there (and the newest). But divide 3,000/8 = !!!

People have said they are very happy with rebuilt Zeniths. Search for posts on that here. And it's your labor vs. your labor to save $$ to buy something else. It's the old HD Thoreau train thing... he said he could walk somewhere faster than take a train (as he had to work a long time to earn train fare). It's obvious what to do, right?

911-m5 · 11-09-2004, 02:02 PM

Yes, I hear you Randy. I dropped them off to a mechanic today to see if they are worthy of a rebuild. I really hope they are. I do have a second job in the works doesn't pay much better but more hours worked equals more dough.