TR2/3/3A RE: Pulling the choke knob all the way out....the carb jets should be down how far?

[karls59tr]

Was it 3/16" or 3/8" from the nut? I can't find the link where I read this. If the jets were not pulled down far enough how would this affect idle? And how would it affect idle if they they were pulled down too far?

 

[mezy]

What Carb are we dealing with Karl, Im thinking SU

 

[karls59tr]

Stock TR3 HS carbs.

 

[mezy]

Thought so, we call them SU here in the UK.
The way I have always set them is push the choke all the way in, push the choke tube on the carb all the way up and connect the cable.
Pull the choke out, push it back in and make sure the choke tube on the carb is all the way up.

 

[CJD]

Hey Karl,

The actual number is something I have never measured. The important thing is that the jet retracts fully (in or up) until it contacts the adjustment nut when the choke is in fully. If it does not go up fully, then your engine will run rich (rough idle with black smoke out the tail pipe), and you will not get any adjustment from the nut to fix it.

With the jet fully up, you connect the choke cable with the knob fully in. The amount of jet movement is now set by the linkage geometry, and you don't have any control over it unless something is bent or damaged.

 

[sp53]

In Washington State where I live in winter, they need to come down about ¼ to 5/16. They should come down equal, but good luck with that because the geometry of the sloppy levers and the rod that connect both chokes is tricky sometimes to get both the same. The front choke wants to pull down a little more than the back probably because it where the pulling starts. Like John suggested it is critical they return fully. My front choke is probably 5/16 and the back ¼.

steve