Setting up the carbs

[JSutton1]

So the answer to my question last week about the leaky carbs was I was missing the aluminum washers under my fuel inlets. Put them on and walla...no leaky, and improved idle. Thanks so much for your help.

What I expect to do next is:

1. Synchronize my idle set screws.
2. Adjust the accelerator screws that link the throttles on both carbs together.
3. Adjust my fast idle screws
4. When I rev the engine, it doesnt slow back down. I believe that has to do with setting the De-accellerator diaphram.
5. It seems the idle mixture screws really dont do much.
6. Lastly look at the needle adjustments

Did I leave anything out?

BTW I drove the car for the first time Saturday on a back lot behind my garage. Big moment although I never got out of 1st gear.




Jim

[jclay (RIP 2018)]

Jim,

I don't know what you have already been told, but I do know that when you synchronize your carbs, you have to loosen the links that hook the carbs together. If you don't do this, any change to one throttle will transfer to the other. Once you have them synchronized, tighten everything back down.

[JSutton1]

Thanks, I had heard that.

How critical is it to use the carb tuning tools? Can you get away with listening to a vac hose placed in the mouth of each carb?

Jim

[Rblackadar]

Yes you can. I however have the synchronizing tool and intend on using it seeming that it's probably more accurate than my ears which are FULL OF NASTY WAX!!!![:p]

[Howard722]

I assume you`re on Strombergs over there?- my tip is forget the vacuum tube trick, never worked for me, buy the air flow balancer tool-you won`t believe how far out they can be and the difference when thay are A1 is amazing-SU`s on my TR but Strombergs on the old Vauxhall beast!

Enjoy& regards

[JSutton1]

Am I correct about the decel valve? If I rev up, it takes quite a while to some back down.

Jim

[jclay (RIP 2018)]

I used to use a four gauge vacuum set-up to sync the carbs on my motorcycle. You would use a single vacuum source to zero all of the gauges, then each carb has an out let just for tuning. You would hook the corresponding hose to each of the carbs and start the bike. then you could quickly set each idle position. Too bad that there isn't anything like that on LBC! Of course, there are no crossover tubes on bike carbs.

[Hasbeen]

Jim, you are probably right about the deceleration valve, but you
should make sure the simple things are right, before you get to
changing anything.

I always remove the EGR valve, [which is a ridicules bit of cr4p], &
fit a blanking off plate, with a tang to take an extra throttle
return spring. This looks neat, & even if it doesn't do much, to
help shut the throttle, it does remove one source of idling problems.

My SUs don't need, or have a deceleration valve, but the return to
idle becomes slow, the idle revs rise, & the application of small
throttle increases at low revs, becomes jerky, about every 6 months.

I live in a dry, dusty area, & these minor problems are caused by a
build up of dust & oil fumes, mostly in the throttle cable.

I remove the cable, disassemble, & wash it out with petrol. After
drying, I lubricate it with a little dry graphite powder. I then
wash the throttle linkages, & the throttle spindles, leaving
them dry. I find contact cleaner very good for this. This always
returns my throttle response to what it should be.

Hasbeen

[flynns tr 7]

Halfords sell carb balance tool not to expensive. Worth the investment considering that you will need to check the carb balance at least yearly prior to your mot plus the fact the splindles wear ,needle wear.I use a crpton balance tool had it for years worth getting hold of if you spot on at an auto jumble