G'day,
thanks for all the replies about gear box noises, it's now sorted with a new 3.4 diff and lay shaft + bearings so it now goes faster without a tooth missing off the diff pinion being very evident.
However with the onset of cold mornings in Brisbane I'm having quite a job starting so I checked out the 11/2" carburetta, it appears to me the choke is not really doing much.
When the choke os operated through the pull cable for it's entire length the cam operates the throttle lever but the jet does not drop until the final stages of the cable, it only dropps about 4mm.
I removed the carb and checked the choke mechanism and I can see the lag built into the little levers but when operated by hand to achieve the full range of the jet against it's downward stop the cable attach point has gone past the cable entry point.
So can somebody please tell me 1/ how far out does the choke cable come when you pull it to the max, 2/ how much does the jet drop at max cable pull, BTW the connection pushing the jet down is a stout wire about 2.5mm, is that a very early type, I say that as mu SU booklet and Mini Manual show a pressed metal lever,
regards Joe.

a long time since I've had a choke, but...

1. maybe 2"
2. maybe 8mm

I used to set mine up so that the cam was rotated almost to the point where it contacts the idle screw when the choke was pressed all the way in. That way the whole lot didn't have to turn as far when I pulled the cable out

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G'day Simon,
thanks for that, every bit of info helps.

I was just talking with Matt Reid here in Brisbane and he was sure I had the choke cable in the wrong place, IE. it is pulling vertically instead of more horizontal from near where th throttle cable is attached, I reckon he is correct, I might need to get a bracket from him,
thanks again.

G'day,
OK the choke now sorted and she starts from cold second go no worries, just another question on the SU.
My carb has two attachments for anti polution hoses? one say, 5/16 brass tube pointing up at 45deg quite near the fuel bowel while the other much smaller with a barb end pointing vertically
just behind the butterfly, at the moment they are joined together by a small into larger rubber hose, is that the correct way?
joe.

The small one is for vacuum advance on the dizzy. The large one for crankcase ventilation.

The 5/16" one would have originally had a plastic thing on it that made it 1/2" OD for a breather hose.

Having them connected together doesn't have any effect as they're both connected to the same chamber, but isn't the way they were meant to be set up

If you don't have vaccum advance on your distributor, the little one should be blocked. You might as well block the other one too unless you have somewhere to connect it to a breather.

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did I tell you that I won a trophy?

G'day,
thanks for that, I'll block them both.