All the linkages etc were free and lubricated with no signs of sticking. There was no signs of any air leaks and all the breather hoses are connected and in good condition. Next thing was to put a flow meter on the carbs, and sure enough the front carb was drawing much more air than the rear one. The next thing was to loosen all the links between the carbs and set the idle on each one but even with the throttle stop completely undone the front carb was still drawing way too much air.
|Synchrometer, air flow meter I use.|
Next thing to look at was the float levels. The newer types of SU carbs have a one piece plastic float which is non adjustable. Some folks put washers under the needle valve to alter it but I decided I might as well fit the best new ones from Burlen Fuel Systems. These are called StayUp Floats and come complete with a new needle valve and gaskets as well so should be an answer to the fuel level problem. They also have a metal lever so are adjustable as well if needed.
|Burlen SU StayUp float kit|
The engine now runs much smoother and I can actually adjust the tickover to a nice 750/800rpm. It also drives nicer and pulls strongly from low revs. I popped into my local garage and checked it on their emissions tester. CO2 levels were a little high so I set them down to a comfortable 4.5% .
We are out on a little Sunday tour with our GLAVON TR Register group tomorrow so it will be interesting to see how it goes in normal driving.