Setting up dual carby Solex

Update.

Couldn't get the twin SUs to run properly. Tried all sorts of things, from cleaning out and checking the carbies, to swapping oil and playing with levels, to changing timing and idle speed.

Would just keep spluttering from 3000rpm upwards, and wouldn't do a thing.
Considering that it ran fine with the holley, I am just putting it down to dodgey carbies (could've been sitting around in the shed way too long or not balanced right).

Am currently in the process of putting the holley manifold back on.

Found that the car still had it's mysterious 'non starting' issue when the twin carbs were on, so I figured that it has nothing to do with the holley flooding at a particular angle or anything. Will be looking more into the dizzy, ignition amplifier module and possibly even the starter motor.

Its all good fun anyway.

Hey Jezza, are you going to get the SUs rebuilt?

There are 2 possible sources for the poor running at higher revs,1 being fuel flow,if the electric pump is slow then it could be starving, but if you don't have that problem with the Holley then that is out,the other could be the Vacc advance,and or timing,I run 10* advance on our 85 model,petrol/gas and I use 20 grade oil in my dampers,filled to the bottom of the threads, with the carby needles set at the middle setting,the condition of the Vacc advance hose is critical,also the Lucas Electronic ignition unit is designed to only take a 55,000 volt coil NON RESISTOR TYPE, or it will overheat,mine had a Bosch GT40R on it, I replaced it with the correct coil and all poor starting high rev missing vanished :) It can sit for weeks and start (no throttle or choke)in under 30 seconds.

If you suspect vacuum diaphragm, try www.advancediaphragmoptions.com up in Caboolture Qld.he does an exchange unit that is what I have got on mine,it has been ther now for 5 years no problems.

Hope that is of help to you.

cheers

Quote:

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Originally Posted by UncleHo

There are 2 possible sources for the poor running at higher revs,1 being fuel flow,if the electric pump is slow then it could be starving, but if you don't have that problem with the Holley then that is out,the other could be the Vacc advance,and or timing,I run 10* advance on our 85 model,petrol/gas and I use 20 grade oil in my dampers,filled to the bottom of the threads, with the carby needles set at the middle setting,the condition of the Vacc advance hose is critical,also the Lucas Electronic ignition unit is designed to only take a 55,000 volt coil NON RESISTOR TYPE, or it will overheat,mine had a Bosch GT40R on it, I replaced it with the correct coil and all poor starting high rev missing vanished :) It can sit for weeks and start (no throttle or choke)in under 30 seconds.

If you suspect vacuum diaphragm, try www.advancediaphragmoptions.com up in Caboolture Qld.he does an exchange unit that is what I have got on mine,it has been ther now for 5 years no problems.

Hope that is of help to you.

cheers

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with the standard carbs.... mine can sit for months and still fire right up first kick of the starter..... I just let the fuel pump run until I can hear the fuel gurgling back too the tank through the return. Full choke, no throttle and it'll fire to life on a handful of cylinders and slowly pickup the rest. I figure it primes the carbies at different rates, so knocks away on 4 cyclinders on the first carby until the other carby primes itself and starts working.

Just go through it systematically and put everything back too standard........... that's what I did with mine.

You can buy the full plugs/leads/cap/rotor button set out of Tassie on ebay for not a lot of money. However check your dizzie is assembled properly. I always learn everything the hard way .... ie: I pulled on the rotor button and ripped the centripetal springs off ..... Someone may have done this too yours in the past and re-assembled incorrectly.

I also found both caby pots empty, the vacuum advance hooked up to the wrong spot so it was always at full advance.... Not to mention the was a one way valve in the vacuum advance line .... So as soon as there was vacuum there on first startup, the one way valve kept it there.

She sure does run nice now. It's never fast, but always seems to rumble along quite effortlessly. Gotta love the sound that tiny little V8 makes as it drinks every bit of fuel I can stick in it's tank at a horrifying rate :wasntme:

seeya,
Shane L.

That's why mine has a big 80 litre gas tank in the back :D and on carbys it is only the width of the adaptor plates on the carbs the standard aircleaner provides the required vacuum suction.and with extractor exhaust and free flow muffler the sound is music :D one of these days I will find a set of scuba tanks to replace the big one.

cheers

Quote:

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Originally Posted by UncleHo

There are 2 possible sources for the poor running at higher revs,1 being fuel flow,if the electric pump is slow then it could be starving, but if you don't have that problem with the Holley then that is out,the other could be the Vacc advance,and or timing,I run 10* advance on our 85 model,petrol/gas and I use 20 grade oil in my dampers,filled to the bottom of the threads, with the carby needles set at the middle setting,the condition of the Vacc advance hose is critical,also the Lucas Electronic ignition unit is designed to only take a 55,000 volt coil NON RESISTOR TYPE, or it will overheat,mine had a Bosch GT40R on it, I replaced it with the correct coil and all poor starting high rev missing vanished :) It can sit for weeks and start (no throttle or choke)in under 30 seconds.

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I am unsure what type of coil is in there at the moment... Fairly sure it is a standard Lucas item, but could be a Powerspark - although I'm fairly sure they use the Lucas items in their kits also.

I do have a problem with overheating though. Sometimes in the heat, it just refuses to start or even turn over. Usually I can manually crank the starter with a wire straight to the battery - although even this wouldn't work the other day.

Quote:

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Originally Posted by DoubleChevron

You can buy the full plugs/leads/cap/rotor button set out of Tassie on ebay for not a lot of money. However check your dizzie is assembled properly. I always learn everything the hard way .... ie: I pulled on the rotor button and ripped the centripetal springs off ..... Someone may have done this too yours in the past and re-assembled incorrectly.

I also found both caby pots empty, the vacuum advance hooked up to the wrong spot so it was always at full advance.... Not to mention the was a one way valve in the vacuum advance line .... So as soon as there was vacuum there on first startup, the one way valve kept it there.

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Thinking there is a problem with either dizzy/leads/amplifier module.
Probably a combo of a couple. I removed the dizzy to replace those 2 heater hoses behind the water pump - when we put it back in and checked the timing with the timing light, the #1 or #7 lead wouldn't activate the light for some reason. When we pulled them out, the leads would still spark on a metal surface though. After pulling out all the plugs and cleaning & gapping them, I think it came good.

The holley is in and running, although there is still a bit of a miss in the higher revs. The leads that are on it are fairly fresh, but they are cheapies that are fairly thin... We have some decent ones on a spare engine in the shed so will swap them over and see if it makes any difference.
The holley is much more responsive down low though, so can be driven quite well at the lower revs anyway.

Have been eyeing THIS off on ebay to get it all new and running well again, but I would still need to relocate that amplifier module so it was a bit further away from the heat.