This piston has a tapered, conical metering rod usually referred to as a needle that fits inside an orifice jet which admits fuel into the airstream passing through the carburettor. This second paper deals solely with su theory and tuning, the latter being the. They should be removed from the engine for cleaning. Manual choke hd carburettors have an external lever which pivots on a. Tuning your su carburettors by scott fisher ive been meaning to write this up for some time, ever since i did the su performance tuning 101 a few months ago. If the dirt seems to be baked on, use some of your carburetor cleaner to free it up. Pdf su carburettors tuning tips and techniques download. Su carburettors the su carburettor is a relatively simple design but has proved to be very effective. Completely covers overhaul and tuning of slide, constant velocity and fixedjet carbs.
A determined individual can cure finetuning glitches normally resolved at the factory. Skinner union carburettors, many motor mechanics still encounter difficulty when tuning and adjusting these relatively simple units. Since the needle is tapered, as it rises and falls it opens and closes the opening in the jet, regulating the passage of fuel, so the. This is due the su being analogue and the vast array of needle profiles available.
This is very high compare to a typical wire mesh which has a free area of only 30% 40%. Article 7 adjusting the carburators new hill garage. The first is to set the fuel level in the float bowl, the second is to centre the needle in the jet, but only with fixed needles, not spring loaded ones, the third is to balance twin carbies. Before proceeding to synchronize your carburetors and for best results, some preparation is in order. Some sus also have exhaust emissioncontrol devices to comply with antipollution laws. Provides sound knowledge of the principles of carburetor function and details the practical aspects of tuning and correcting maladjustments. Check the throttle for correct operation and signs of sticking 3. Pdf download haynes manual on carburettors free ebooks pdf.
Rivera primo su eliminator ii carb kit harley davidson 1955 to 2006. Before tuning the carburettor, carry out all the checks in checking and. Reconnect the mixture control wire with approximately 116 in free movement before it starts to pull. Recheck fuel mixture, and carburetor synchronization. Balancing hif su carburettors morgan owners club of australia. Stromberg ww carburetor manual stromberg ww carburetor manual 1955 edition. The mixture strength of each carburetter should be checked, one carburetter at a time, by the method previously described in the section on tuning single h type carburetters. A chassis dynamometer, of the proper type, is the best way to solve tuning problems or misfiring. Haynes su carburetor manual thank you for downloading haynes su carburetor manual maybe you have knowledge that, people have look hundreds times for their chosen novels like this haynes su carburetor manual, but end up in malicious downloads book haynes su carburetor manual haynes weber carburetor manual. Construclion and functioning of basictype carburetter. The following should be checked on the engine prior to setting up the carburetor to determine if the situation will lend itself to optimal timing, or. Unlike other types of carburettor, which have fixed jets, the su has only one jet, so the mixture setting affects the engine throughout its speed range. Here, then, is an explanation of the principles of tuning, fol lowed by a simple. Adjust the pegs on the ends of the interconnecting linkage until there is approximately 116 inch clearance free play before the peg contacts the slot on the carburetor tab.
Su carburettors tuning tips and techniques repair manual. To carburate or carburet and thus carburation or carburetion, respectively means to mix the air and fuel or to equip. The information presented is from my experience, it is not intended to take the place of an su manual, or even just the carburetter section of the shop manuals out there. Haynes motorcycle carburettor manual pete schoemark.
It is sometimes colloquially shortened to carb in the uk and north america or carby in australia. These instruments are essential when tuning vehicles equipped to conform with exhaust emission regulations. Curiously, given that the whole book revolves around altering needles to suit sus with no or little spring or damper, the book makes no reference at all to early su carburettors brass piston which had no spring or damping rod. In essence, this book tells you how to modify su needles should you wish to tamper with the dashpot spring. A carburetor american english or carburettor british english is a device that mixes air and fuel for internal combustion engines in the proper airfuel ratio for combustion. Free carburetor repair manuals mikes carburetor parts. It is the ratio of the free volume inside the cylinder at. Pull the mixture control knob until the linkage is ab. The trick to tuning su carbs is to understand that there are two things you need to get right. Your carburetors should be in peak condition with no play in the throttle shaft bushings. The often underrated su offers good versatility and reliability.
The su carburettor high performance manual speedpro. A few years back, a genius over at developed a handy charting and searching tool for just that purpose. This position is set when the carburetter is tuned for idling. Tuning su carburettors including full needle charts, 1968 speed and sports publications ltd acorn house, victoria road, acton, london w. Covers tuning tips and techniques for su carburetors as well as all su fuel pumps for numerous classic cars, including the mini cooper, sprite, bentley, jaguar etype, jaguar mk 2, daimler v8, land rover, mgb, rolls royce, tr4 and tr7, spitfire, rover and volvo 1800. Unscrew the fastidle adjusting screw 2 to clear the throttle stop. Manchester xpag tests fuel and tuning part 2 choice of. Tuning your carbs need help figuring out which skinner union su needles you need to keep your car running right in all throttle conditions. This is a home brewed tuneup procedure written in laymans terms for the doityourself mechanic with a limited tool inventory.
Unscrew the throttle adjusting screw on each carb until it is just clear of the throttle lever with the throttle closed, then turn the screw clockwise one turn on each carburetter. It has only one jet except in a few special types and very few moving parts. I created my own pdf after someone sent me what i thought was a xerox of the actual book but is more than likely a printout of the. Background su carburetors are marvelously simple devices that work wonderfully well, despite everything you have heard or even have experienced on old, wornout british cars that are decades away from the condition they were in when they left the factory. Tuning su carburettors sterling british motoring society. Follow the instructions in the tuning guide for establishing a base line, make sure linkage is loose and reset idles making sure that the fast idle screws are clear of the fast idle cam. Setting up and tuning su carburettors tools screwdriver spanner adjustable spark plug spanner jet adjusting spanner early cars carburettor damper oil length of tube or hose carb balancer optional the su carburettor is a simple design proven to be very effective. When all the carburetters have been checked and any adjustment made, it is necessary to recheck because of the influence of each carburetter on all cylinders. Make sure all components of the ignition system timing, plugs, points, and wires are properly adjusted and working well, and that the valves are adjusted to specification before trying to adjust the carburetors. Su carburettors can theoretically perform better than modern computer controlled fuel systems.
All british cars austin healey 100, 1006, 3000 classic mini jaguar etype jaguar xj6, xj12 jaguar xjs jaguar xk120, 140, 150 mg midget, austin healey sprite mg tc, td, tf mga mgb mgc morris minor triumph gt6 triumph spitfire triumph stag triumph tr2, 3, 4 triumph tr6, 250 triumph tr7, 8. On some su carbs, enrichment of the mixture when accelerating is provided by a. A vacuum gauge is the best way to reproduce an exact load condition for a given engine speed and gear. Mine was a rust free canadian car with an amazing history that i imported in 2003. Many of the parts of su carburettors are interchangeable between sets. Su carburettors featured a variable venturi controlled by a piston. Adjustment of these is described in adjusting an emissioncontrol carburettor. Even a firsttime novice should be able to precisely tune carburetors in 15 minutes or. These instructions do not cover tuning su carburetors. Frazernash blackburne engine 1934 su hv2 prewar triple set. Tuning su carburettors even though a large proportion of modern motor vehicles are now equipped with s.
Setting up and tuning su carburettors classic car hub. Rivera primo su eliminator carb kit harley davidson 1955 to 2006. It is very reliable, but it can become dirty and choked and some parts wear out. To achieve the best results when tuning, the use of a reliable tachometer. This one is more like basic su adjustment for happy driving. Pdf haynes manual on carburettors download ebook for free. Download pdf su carburettors tuning tips and techniques book full free. The idiots guide to tuning su carburetters there are four distinct phases to tuning su carburetters carbies. If after resetting idle, one carb still appears to draw more air, you most likely have an internal engine problem. Moss part numbers 215 and 2145 are two such guides. Engine tuneup the casual way cf120 after years of resisting the temptation to rewrite the shop manual, i am posting this by popular demand. Print page harvs norman supercharger thread maybe guys on here could take some tips from developments this ability of su carburettors to have a small i would recommend tuning su carburettors by austin riley gumtree australia free local classifieds find austin riley ads. Su carburettors tuning tips and techniques available for download and read online in other formats.505 369 1624 273 1100 77 655 509 539 844 413 1144 576 1365 385 684 482 263 370 602 456 602 1031 177 1370 55 865 1095 761