No reliable way of distinguishing an original. The copy has changes only seen on late model ones such as lock nuts requiring a special screwdriver on the adjusting screws, but these are easily swapped, so no real way of telling, except that if it looks very new it probably is a copy.Quote:
Originally Posted by dearot
Which is best depends on what is wrong with the one you have. What usually goes wrong with these carburetors is generally:-
1. Badly sealing O-ring. Both seats must be clean and undamaged and the O-ring in perfect condition. Watch for wrong screws or washers or burrs on the screws holding the emulsion block, as there is little clearance and these may be causing lack of pressure on the O-ring. This is by far the most common issue with these carburetors.
2. Warped top cover. Results in air and fuel leaks and contributes to 1. Lap flat on wet and dry on a sheet of plate glass.
3. Worn throttle spindle and throttle body. Needs the throttle body rebushing and new spindle. Unless you have the tools and skills to do this, it will be far cheaper to get a copy.
4. Dirt blocking jets or passages. Clean them, being careful not to damage them - fit a filter just before carby.
5. Damage by previous hamfisted owner or mechanic. Depending on the extent, replacing the carby with a copy may be the best option!
Gaskets may need replacing as part of the above, and the needle valve and seat rarely. Even more rarely, I have encountered a leaking float.
