Dellorto Tune Up Using Rubber Pipe

[William2]

I have just stripped down both my Dellorto DHLA40E carbs as I couldn't get the engine to idle smoothly or pick up on acceleration without sounding rough. I blew out all the jets and carb body holes and orifices with compressed air and double checked all the butterflies to ensure they were a good fit in the barrels, etc. I then set all the idle screws to 3 1/2 turns as a starting point. With the carbs remounted and the airbox cover removed I fired the engine up. Although I have a Synchrometer I decided to use the good old fashioned method of a length of rubber hose and listening. I adjusted the balance and idle screw and it didn't take long to get all the carb trumpets singing the same notes!! Took the car out for a spin and it is 100% better. Smooth tickover and no coughing or spluttering. Tomorrow I will have a go at adjusting the idle mixture screws but beforehand I will take the plugs out to check the colour. I was advised by a garage mechanic who had a lot of experience in twin cam engines and tuning to use this method and I must say it does seem to work well.