Carb Confusion!

[Air Cooled Rookie]

My van is a standard 1600 twin port with a vacuum distributor and a solex PICT 34 carburettor.

The problem with it is that the heat riser is not allowing any heat to rise and the carb has worn spindle bushes and the thread which the mounting studs screw into are very weak, so you can’t really tighten the securing nuts up tightly. A replacement carb I bought 2nd hand is in a similar condition.

In short, I need a brand new carb and a new inlet manifold. And this is where my confusion starts!

My main priorities are:
1. Availability of parts. I need an off the shelf solution that can be fitted over a weekend (preferably in a day) as my van is my only means of transport and I need to drive to work
2. Fuel economy
3. Reliability and ease of setting up
4. Initial cost of the parts

I’ve done a search on carb options on various forums and am slightly overwhelmed by the amount of information and the vast differences in opinions. So my questions are:

1. Are the PICT 34 replacements that Just Kampers sell the dreaded Bocar versions that everyone agrees are rubbish?
2. If so, does anyone sell quality replacements off the shelf? (I don’t have time to buy a used VW/Solex carb and have it overhauled/re-bushed)
3. Is there any difference between Kafer and Bocar carbs?
4. I’ve been put off the idea of a progressive twin choke weber because of tales about carb icing and major problems with linkage. Is this a fair?
5. Would the Solex dual 34mm set up that Speed Shop sells meet my economy/reliability/easy set up criteria?
6. Are these Solexes empi copies or original?
7. Will they fit with the standard fan housing?
8. Can I still run a vacuum advance distributor with twin carbs?
9. I’ve read that the Delorto DRLA 36 are the ultimate set up for a 1600 twin port.
10. Who sells these and is the linkage easily available?
11. Would this set up cost more than the £325 that the twin Solexes cost?
12. If I fit twin carbs, do I have to hack out the original air filter stand?

Sorry for all the questions, but there are so many different opinions out there that it can get quite confusing.

Thanks.

 

[james_stan]

Hi There

Let me start by answering point 4..

I think the progressive is OK. You will need a working choke though in this weather (mine does not have one and thus takes quite some time to kick into life). I believe some manifolds are better(worse!) for icing than others (and there are a few choices -SCAT may be best) mine seems OK but you may have to allow a few minutes warm-up.

The linkage can be a nuisance since the throttle 'arm' requires more travel than the standard carb and also the angle is not great (too acute) coming out of the fan housing. Most peeps cobble together a lengthened arm and extended at the throttle pedal as well - see VZI for linkage ideas.

You will get it fitted in a weekend no problem but you may have to fettle the linkage to get 'full bore'. OH yes and no
need to remove the air filter stand. Economy ? Not too different from stock IMHO.

Good luck

James

 

[currylager]

You could do with a carb and manifold off a blown engine, one you can just bolt on and get you back on the road with a few tweaks. I do actually have these items but the carb is probably a bit worn, anyone else got anything :?:

 

[cyberdyne systems]

I have a bocar fitted and to be honest it runs pretty well and has the correct economy. I found the choke was sticking and the nut that holds the choke cam fell off, but once I had sorted this, its been good.

The only thing i do get is when coming off the power, the idle drops a little low and then comes back up, and some initial stalling when I restart on a warm engine - occasionally. Now whether these issue's are down to the carb I dont know, but as everything else isn't new, I just put it down to general wear and tear/or carb quality. Also I need to give the motor a service, which usually restores it to near perfect.

Gareth

 

[noddy]

Hi Rookie

Take care when buying after market (non stock) carbs and mixing with a vacuum advance distributor. So aftermarket carbs webers etc can produce too bigger vacuum signal and cause the distributor to advance to full at tick over.

I would check out the samba.com I have bought carbs from the US and generally they have been ok once rebuilt. You should be able to find a good 34 pict second hand try these guys http://www.bustedbus.com" onclick="window.open(this.href);return false;.

Good luck

 

[Harlequin]

Carb on ebay
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=170282617810&ssPageName=STRK:MEWA:IT&ih=007" onclick="window.open(this.href);return false;
or try the guys link to Vzi

http://www.volkszone.com/VZi/showthread.php?t=454783&highlight=carb" onclick="window.open(this.href);return false;

 

[Hilly_70]

I have a spare set of new bushes available for the bottom spindle if they would help .. you can have them for what they cost me .. I would stick with the/another original one if possible though .. I have a spare one for parts too should you need any bits off it ..

Cheers

Hilly

 

[ronmidg]

Re your question 4. We have a weber progressive on unheated manifolds and it really is awfull, even with a warm engine, the fuel condenses in the manifolds and pick up by the air is ok at high rpm and not at low rpm, its driveable in the cold as long as you keep one foot on the throttle, but then you need three feet in traffic. Itmay be ok with heated manifolds, I have no experience, I have seen heated manifold kits for for the type 1 installation, but not the 25 which we are running on the bay.

I have twin ICTs on the split (1600TP type 1) with no heating, and no chokes, but with very short vertical manifolds thick aluminium, they warm up enough in a few seconds to idle smoothly. Re question 5, the ICTs are 34mm, throttle response is improved over the stock single they replaced, torque seams better throughout the rev range, suspect use more fuel though. Dont know the solexes but would definitely vote for a twin set up over stock single. Be careful when fitting stock exhaust, some sellers will sell one exhaust to fit 1500 and 1600, the outlet is smaller than the correct 1600 and it noticeably strangles the engine if you have fitted a better intake set up.

Q8, vac advance, yes, you need the carbs to have the fitting, then there is the debate about how much vacuum from different carbs, I dont think I get enough from a single tapping on the ICT, I intend to try a double connection with anti pulse valve etc but thats for the future.

Q9,10,11, Dells are highly rated, but not made anymore, were most recently fitted to the Alpha boxer engines so there is a 2nd hand trade going on, check out ebay, everything else besides the carbs themselves is available new if you cannot find on ebay. About same cost, say £100 for the carbs secondhand plus £200 for all the bits and pieces new. Am going this way for the bay but not completed yet.