I have an HP .61 with a slide accelerator pump carb. I am having difficulties getting it to run rich enough. Once it has gone lean it is very difficult to get it to come rich again. It needs to be set very rich, almost 4-stroking, in the horizontal for it to continue running in the vertical while tuning. I have cleaned the carburettor as best I can, however cannot clean inside or through the pump. Is it possible to remove the brass pump from the aluminium carb body for cleaning and/or maintenance. Has anyone else got any advice on how to remedy this problem. I am running a APC 12/6 prop at approx. 12000 RPM on 18% oil, 6% nitro, Coolpower Blue synthetic oil.
Thanks for your suggestions