Posted by: the59bug - 14 August 2008 12:46:45
Hi guys, I've just rebuilt the carb on my '59 1200 30hp. It's a Solex 28PCI (Not PIC or PICT) The emulsion tube snapped when I was nipping up the air correction jet. Looks like it had a hair line crack for quite awhile. I got a donor carb to get a replacement emulsion tube. My problem is now too much airflow, I think. It runs fine on tickover and when you blip the throttle. But as soon as you apply revs and the venturi kicks in, it runs really bad. Misfiring etc. Running really lean. Anyway, the only way I can counteract the problem is to set the choke flap slightly closed to decrease airflow into the carb. This does the job surprising well actually until you get over 50mph (I don't do more than 60mph by the way!), then it starts to rough lean again and runs rough with a few back fires. I've checked timing, ignition etc. Gas analyser shows good % of fuel until the revs increase then it drops really low. My local guy reckons I should try and get hold of a new carb. (NOS) But the car ran absolutely fine for the last 7 years. I don't think it's pulling in air through the throttle shaft, I'm not a carb rebuilder but it doesn't seem to have any play. Maybe a tiny,tiny bit of movement but I don't know enough about these things to know if that could be making such a difference. I'd only know if I fitted a new carb but I want to see what you guys think before I go to those lengths. I think I've explained that OK. Any advice would be appreciated. Here's hoping finding a 'New Old Stock' Solex 28PCI is not my only option! Jay

Posted by: Rich Oakley - 14 August 2008 21:00:44
1. Was the car running fine before? If so, why was the carb rebuilt? 2. Did you use a new/different volume control (mixture jet)?

Posted by: the59bug - 15 August 2008 01:39:57
Hi Rich, It started to run rough after running it low on fuel so I took the top off the carb to check for dirt and it was pretty dirty. One of the jets was partially blocked so I thought great, whip it off, blow out the jets etc. It was while re-screwing the air correction jet in the top of the emulsion tube that the emulsion tube snapped. This is the only part I have replaced, all jets are the originals. Jay

Posted by: Rich Oakley - 15 August 2008 09:53:27
I would strip it down again and make sure the body is blown through thoroughly with a high pressure line again. Sounds like the idle circuit is just fine, but there might still be a spec of dirt in one of the accelerator ports. Inside a 28PCI carb, there are two very narrow accelerating ports drilled into the wall of the throat near to the throttle valve. These ports are a much smaller diameter than the other internal passageways in the carb and can easily get blocked.

Posted by: the59bug - 15 August 2008 12:40:34
I soaked it in parafin for 2 days, sprayed it with carb cleaner and I own a compressor so blew the hell out of it until it was bone dry. However, now you describe those very narrow accerelating ports it has given me a glimmer of hope. I'll let you know how I get on! Anything else you could suggest?

Posted by: 356boy - 30 October 2012 09:21:27
hi, sorry to but in but could you clear up which is the air correction jet and what size it should be please, i have fitted pepco and i need to change the air correction jet to 052 on the same carb you have. thanks