Hello, The problem I have is on start up the dynamo (c35sd) on my 51 sq4 doesn't seem do do anything until after about a minute of running it comes to life, I have to rev the engine and sometimes switch the lights on and off to get a + reading on the ammeter. I overhauled the dynamo during the rebuild. I have a new battery fitted and use a DVR2 regulator. After the dynamo kicks in it charges ok, but I have to go through the same sequence on initial start up. I'm thinking the field coils are weak.