Carb options.

[haz]

Having recently cleaned up & re-gasketed my stock Solex 32-34's Im wondering abut the amount of play on the spindles and if there would be any worth in considering replacing them all together?

Cars a stock engined 1600 twin carb, not rebuilt or in top notch condition but running reasonably well.

Im in Nz and simply due to the cost & availability of parts & services here it prob cheaper and defiantly easier to simply replace with new carbs!!

Im wondering about a conversion such as webber dual 34ICT's, seen these for about $400us as a complete kit, most likely cheeper than having mine repaired.

Guess the first questions are, how much play is too much in the throttle butterflys and does it matter for the choke butterflys?

Cant say Im overly keen on foam filters instead of the oil pan though.

Any thoughts?

[miketyp3]

Just take the throttle bodies to a machine shop and get them to bush the spindles, it will cost less than ICT's which are rubbish.
There should really be no detectable play in the throttle, the chokes are less important.

[Marko]

I had my throttle spindles re bushed for £30, bargain really considering how much a a pair of new carbs are! still haven't tuned them yet but the engine ticks over nicely with just base settings! choke spindles should not have anything near the same amount of play..

[corndog]

"ICT's are rubbish" Yes outta the box, but if you set them up correctly IMO they're far superior to overly complicated stock carbs.

I've got the original oil pan on my ICTS (fits perfectly) and a stock looking linkage system which i had to build. That's one problem with the ICTS, the linkage system is crap.

Problems with the ICTs

-Badly bushed
-wrongly jetted
-needle valves are the wrong size
-no fuel cut off switch
-linkage system is poor

Get that sorted and you'll be grinning from performance and mpg!

Initially I spent a week and ££'s rebuilding my stock carbs, and then over a month road testing them with lambda gauge (measures fuel & air ratio), trying every setup, jet etc going. Doesn't matter how they were set they would always burn really rich pottering around town. I've heard similar stories, stock carbs have just as bad a rep as ICTs

[Editor]

If you use carbs without fuel shut off devices (eg the electromagnetic valves), make sure you don't park pointing up a steep hill with a full tank, as it can dribble fuel into a cylinder and cause a hydraulic lock. The starter won't turn the engine, and if you try a bump-start downhill, you may well bend a con-rod!

Before '65 there were a number of such episodes, and that's when the electromagnetic valves were fitted.

[haz]

So,

No further ahead over here~!

I found a spare carb last week and received it to find that the diaphragm arm is about as buggered as mine so will take this to a machine shop and have them weld it & re drill the hole.

Secondly Im looking at having the throttle body's bushed as suggested but see the butterfly screws are pressed over to secure them, obviously I need to grind / file them to remove them but what about putting it back together?, is it safe to try and repeat this myself with a punch or could I simply use thread locker? also do I need a special type of material screw or will any mild steel suit and what is the thread going to be, have little confidence in being able to find a odd ball European size on the shelf here

Ps - Marko, you say choke spindles should have "no were near the same amount of play" do you mean they should have less play than the throttles or that they can have more without it being an issue?

Not exactly enjoying this experience, just hope it pays off when its all back running!!

[Marko]

they should have less wear, the main throttle spindles are constantly opening and closing to suit engine speeds where as the choke spindles open when engine is hot and stay open.

when I unscrewed the throttle butterflies all I did was unscrew them and they straightened themselves out as they unscrewed being a soft material..

Mark.

[haz]

Id say mine have almost the same wear but poss slightly less.

Not keen on forcing them out, they look very well pressed over & goes against the grain to force it through a thread like that, proving hard enough trying to do a simple job without digging the hole deeper,,,,

[miketyp3]

So,

No further ahead over here~!

I found a spare carb last week and received it to find that the diaphragm arm is about as buggered as mine so will take this to a machine shop and have them weld it & re drill the hole.

Secondly Im looking at having the throttle body's bushed as suggested but see the butterfly screws are pressed over to secure them, obviously I need to grind / file them to remove them but what about putting it back together?, is it safe to try and repeat this myself with a punch or could I simply use thread locker? also do I need a special type of material screw or will any mild steel suit and what is the thread going to be, have little confidence in being able to find a odd ball European size on the shelf here

Ps - Marko, you say choke spindles should have "no were near the same amount of play" do you mean they should have less play than the throttles or that they can have more without it being an issue?

Not exactly enjoying this experience, just hope it pays off when its all back running!!

I have always found fileing the butterfly screws flush to the flat on the spindle is enough to be able to remove them without difficulty.
I choose to re-use the screws, but instead of riveting it I "stake" them using a hammer and small centre punch - basically from the threaded side of the screw punch on the edge of the screw to move metal into the spindle.
I wouldn't advise using loctite (or a simular threadlocker) in case its broken down by the fuel vapour and / or heat.
Its very important that the screws are prevented from undoing as they would fall into the inlet tract and be sucked into the engine.

The choke spindles shouldn't wear anywhere near as much because the load on them is a fraction of the throttle, they are also not being contantly washed in fuel vapour, and in any case as they are partally open in service anyway so I would expect the effect of any play in them to be very small.

Mike