Chicagoland MG Club Back to Archives Submit an article Cover Intro & Club Officers November Meeting Minutes The Steering Column New Members Fall Tunedown Party Just Simple Wrench Amtrack Trip Club tools for Loan Awards Banquet Classifieds

Just a Simple Wrench by Jake &Ann Snyder Hard Starting, Winter and Summer For the past two weeks the '71 roadster had started almost perfectly on no more than three revolutions before the neighbors knew it was time to face another day. Then, with only the mildest of warnings, starting became impossible. The explanation for the change is that the very warm summer nights with a low of 70 °F had become just a bit cooler with a low of 50° F. And the reason this subtle change in overnight temperatures became important lay directly ahead of the gear selector lever on the carpet of the gearbox tunnel: The T-handle of the choke lay idly with a few strands of the cable still connected from when it had separated from the rest of the cable at the start of the warm spell. Now it was time for more drastic measures. As the car was needed immediately, there was no other solution except to cover the outer rod that runs between the carburetters with a bit of brass shim stock (aluminum from a can will work, also) and then grasp the rod with a pair of suitably adjusted Vise-Grips. The choke connecting rod was then rotated as far as possible in the only direction it would turn, and held there by wiring the handles of the Vise-Grips to the oil dip-stick. Back in the car, turning the key resulted in an instant start - high revs and rough-running because the choke was set too far, but easy enough to control by manual control of the Vise-Grips. A few starting sessions like this showed the wisdom of fitting a new choke cable using the tip learned from Mr. Twist of drilling the old housing out of the dash with a 3/8 inch bit. The cable and housing were reattached to the fittings on the choke rod on the carburetters, and all worked well into the fall when pulling the T-handle all the way still gave starting sessions that took a dozen revolutions for the engine to catch on 35 °F mornings. As the projection of hard starting at 35 °F is no starting at 20 °F and lower, clearly re-examination of the choke cable adjustment was in order. Simply put, if you want your MG with twin SUs to start in the winter, the choke rod must rotate as much as is possible. That means you have to look at and understand how it is supposed to work: There are two cables connected to two rods that run between the two carburetters. The rod closest to the engine interconnects the throttle butterflies and moves when the accelerator pedal is depressed. The outer rod interconnects the choke mechanisms of the two carburetters and moves when the choke cable is pulled out. This outer rod also has a cam-shaped piece (fast-idle cam) that interconnects each throttle butterfly with the choke for the respective carburetter. While a picture should make this description easier, reference to the appropriate illustration in the Bentley, Haynes or Chilton manual generally is not informative unless you already know what components are missing in the diagrams. Maximum rotation of the choke rod using the T-handle driver's control is obtained by getting the maximum distance between the fixed (cable end) and moving (housing end) of the choke cable. In other words, push the choke in (home), loosen the inner cable connection, loosen the nut that secures the housing connection lever to the choke rod and rotate housing connection lever straight down. Now tighten the nut on the housing connection lever, then secure the bolt-with-a-hole-in-it (also generically known as a "trunnion") to fix the cable. This adjustment has proven reliable for us on MGBs operated at temperatures to - (as in negative) 20 °F. For colder temperatures, take along the Vise-Grips to get the most out of your choke rod rotation.

©1999 Chicagoland MG Club, All rights reserved.