When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Is the copper socket where the pin drops into in an SU carb offset deeper on the right carb than the left.?
Appears to b on these two sets of carbs I am exploring
You have SU HS8 carby's, that is the jet you are looking at. It is adjusted by the mixture screw.
There is a write up in the "how to quick links" at the top of the XJ forum.
If you go to the link below there is a downloadable PDF in post #14. There are some earlier in the thread but not complete.
Read before, did a quick re read. I think when it speaks of the alloy bridge and the brass jet head being flush, here us where I am after clarity.
Neither of the right hand carbs I have here (aud 2510) comes flush with the bridge but both left hand ones do come flush. So is that a design offset or a remarkable coincidence in two sets of carbs.
Both of mine will adjust to flush with the bridge(or maybe a mm or so below it). Just a thought, maybe the mixture screws are not long enough or mixed up with the idle screws.
Idle screws are 4 BA x ¾” SS cheese head, Mixture screws are 4 BA x 1” SS cheese head. Lock nuts are
4 BA Brass nuts. You can try to source these locally but in Brisbane I found only two 4 BA bolts and they were the wrong length, 5/8” . SU Midel in Sydney had them at a premium price.
I sourced them online for 10 of each idle & mixture screws + 20 locknuts for less than I could get 2 scews the wrong length in Brisbane. Link below, and paid with Paypal. BA Fasteners, Imperial Fasteners, Micro Metric Stainless, Small Screws, Ba Screws, Ba Bolts,
Seems by some act of fate i have the only two right carbs to both be grimed down solid in exactly same position. after some prolonged cleaning and tussle they both came free and now they need a clean and oil.
Those jets MUST side "nice and smooth" in the tube, and when done properly, they will adjust to above the bridge. Not a requirement, but the range of movement is quite long.
Gummed up is a word I have not heard for a while, and fits the fault perfectly.
While cleaning noticed much sticky black stuff in rings around some parts and figured later that this must be all that remains of rubber o rings that have melted.
The newer carbs have a rigid wire between the depression levers that allows both carbs to be engaged at once, and it has a cover that links both carbs with a lever but unclean how these once operated.