Triumph Repair: 1980 triumph tr7, twin carbs, chris moss

Question
i hear that you are the man with the answers regarding triumphs and man i need some good answers. following a question/answer that i had read in a previous thread of yours i am looking to replace the auto choke unit on the front carburetor. shortly after rebuild them we realized the front carb was flowing way to much air through the choke and would not change with coolant temperature. currently the only way to get them to balance and run right is to plug off the inlet to the choke. i have purchased the manual choke unit but fear that it is the wrong one for my application. the part number through mossmotors.com is 386-325 it is for the single carb and I'm guessing that would be the fault but the manual choke for twin carbs is unobtainable. the auto choke unit pictured in there parts diagram(part 12) matches the unit on our tr7 but the pics in the installation guide for the manual choke show a different animal all together. also we have had no luck locating a vacuum advance for her. as far as i can make out we have the delco unit and no one has been able to get me much info on replacing it with a Lucas unit or rebuilding the delco

Answer
Hi Chris,

Moss only lists the 386-325 for up to 76 and they list 386-365 for 77-on but that one is no longer available. I don't recognize the unit they show on their Internet site but I did put several of their units on 7's and even found that they didn't quite fit right but I modified their unit a little to make it work and even wrote to them telling them how I had to modify their unit to make it fit.

The unit they are selling now looks like it only replaces the coolant section of the auto choke with a manual control and they keep the main auto choke unit in place.

I had done a lot of work on the TR-7's over the years and was factory trained on the TR-7 when it first came out. But, that was many years ago. I do remember on the earlier 7, I was able to remove the auto choke assembly completely and the side of the carburetor was the same as a manual and I was able to take the factory manual choke and it bolted up to the side of the carb and worked correctly. On several customer's cars I just exchanged their carburetors with the manual choke version but you can't go to a salvage yard today and even find a TR-7.

It seemed that all the auto choke systems Stromberg made were prone to failure no matter which version. Send me a picture of your choke system so I can see what system you have on your carburetor.

Howard

Distributor vacuum advance. If you are unable to find a vacuum advance unit for that distributor you might try looking on the Net of another brand distributor. I was so tired of their electronic ignition failures I often replaced the distributor with units from other cars but I don't remember which ones fit now. I even removed the cam and shaft from a Lucas distributor and adapted it to the 7 and had to drill and tap holes in the plate to accept points and condenser on one.

As I remember it was easier to just switch the whole distributor with the Lucas and then cut the three wires from the electronic ignition and install one of the aftermarket igniter unites inside. You had to leave the electronic ignition box on the distributor because it supported the vacuum advance unit. But before looking for that distributor I would look to see if that vacuum unit is still available.

However, if you are good at making modifications, I would just look at a lot of vacuum advance units to see if you can adapt one from some other kind of distributor. (Domestic or foreign)