Honda-SOHC

Hi. Recently bought my 750k4 privately. Although I couldn’t test ride it it appeared to be going well . There was some paperwork related to carburettor work..Since I have been riding it not all the cylinders seem to want play together. I took it to one place who changed the plugs and said it went fine. It did for a few miles. Took it to another local workplace upon a recommendation. They reckon it is running far too rich and suggested that it would be better off looked at by a specialist. They suggested a Classic Honda near Daventry. They are booked up until end of 2024.
Can anyone recommend a reputable workshop on the South coast. I live near Worthing.

Many thanks Brendan