Thread: Setting up dual carby Solex

Found and solved a few issues.

Firstly, the brakes weren't working properly once the new manifold went on. Turned out that the vacuum non-return valve was broken.

Once I cleaned up the carbs with plenty of carby cleaner and a clean rag, the car started running better. I gapped the plugs also.

Car still splutters in the mid and high range revs, but I'm hoping more cleaning and the right grade and amount of oil in the carbs will make the difference.


What are people's opinions about holley vs solex twin carbs?

What are you doing with the holley setup?

Hi Jezza89,

What does the aircleaner for your carbies look like.

I have CD175 carbies with the rectangular black aircleaners on mine and there is a balance bar (hollow tube) that runs between each carbie.

The carbies should be set up to draw the same amount of air (balanced) between them and this is done via an idle screw on each carbie.
There was (unsure if still available) a balancing tool that you fitted in between the carbs to measure how much air each carbie was sucking.
If you google balancing solex carbies you will see some youtube videos which are useful where they use a plastic tube and listening to air being sucked by each carbie adjust them till they sound the same. (I'm yet to do this) but will when I start her up.

You can check if the mixture is to rich on the carbies by lifting a piston on one carbie with a screwdriver while running....from memory if you raise the piston and the engine revs then starts to falter (its too rich) if the engine doesent race and starts to falter the mixture is about right.

I use a light machine oil in carbies which seems to work well.

I was having what I believed was carbie issues and was looking at fitting a new Holley + manifold.......but may not be the case.
General consensus by knowledgeable people on this forum was to keep the original carbies and I only just fitted manifold and carbies back after giving them a good inspection and clean and while manifold off replaced all the hydralic lifters with new ones.

May be a chance I will turn her over tomorrow but still have to finish connecting pipes and hoses, New filter and change oil, Flush radiator of old coolant and replace with new.

I was also given a carbie rebuilder in Morley (from memory) who was a great source of advice which I can look up from my post and pass on to you if needed.

Cheers

Baggy

Hi Jeremy

On My 1984 one those fittings you circled in red (on the 15th) go to the charcoal canister via a y piece. Basically all they do is stop fuel vapour from the float bowls going straight to the atmosphere. I would have to see which port if you need it but I think it the C for carb one.

How old are the carby diaphragms? old ones split and make them run terrible.

Make sure the breather pipes are not blocked with carbon. I take the hose off each carb and use a 1/4 inch drill with some grease to clean them out.

Get someone to bring the revs up to about 2500 and make sure the pistons are opening the same. Also get them to rev it a few times (not too hard just easy) and make sure the pistons rise and fall at the same rate.

That small hose on top of the passenger side is supposed to be going to the distributor vacuum advance.

Hose connection piccie ...



the polution crap has "fallen" off this one

Thanks for all the input everyone. Got to the root of the problem.

Biggest error was the orientation of the top of the carb. There is an alignment mark on each, one was not aligned, hence running rough.

Have also given all parts of the carb a proper clean and inspection.
Found the correct oil for the dash pot through Penrite. I gave them a call and they were very helpful in advising the correct product and where to source.

Car is running well again, but sometimes has a 'rattle' under load or throttle that I don't recall it having with the Holley.

At this point I will be hanging onto the Holley for another project, but will see if we actually need it or not.

My air cleaner looks the same as pictured above

Originally Posted by jezza89

but sometimes has a 'rattle' under load or throttle

In your box of tools should be a timing light .....

Now you need to check the Ignition timing ... and also that the vacuum advance unit is actually working.




Mr rattle can lead to burning a valve


Cheers
Mike