Hi. What a load of trouble to post! My son bought an 'ancient' Cobra drill and we can find no information on getting it started/petrol mixture strength/ carb settings/plug gap etc. Does anyone have any information on this machine circa 1969??? and are there a set of points that may need attention. Fires up with a drop of 'brandy' in the carb and dies a while later. Many thanks. Concerned Dad.
Sounds like a carby/fuel problem more than points, have attached an operators manual but I don't know what your model is this manual may not be suitable, but google your model and you may find the correct one if this one is no good. You can contact Atlas Copco in Sydney they have a customer help line, they probably have an email address as well. Good luck.
Yep, these were/are all 2-stroke engines. I've seen similar units made by Wacker and Pionjar. Thought about buying the Wacker @ $700, but couldn't quite work out a scheme to get it to pay for itself.
At that vintage, it would have points for sure - easiest way to sort that side, is to bypass them and fit an electronic ignition module.
Thanks to all. This machine was definitely before the age of plastics. Built like a brick ####house! I agree a carby problem -probably a wrong oil/petrol mix. The 50:1 mix in the PDF sounds more modern. Many old machines used a much richer mix -- 1:8, 1:16 or 1:20. If I can find the points, would, like my old Bantam motorbike, fully open might be 15 thou and 7 degrees BTDC be 1.5 thou. Would that be a starting point to get it going? Cheers.
The Petrol/oil mix will not really affect the starting unless you are referring to the gunk in a 2 stroke carby that is left behind when the petrol evaporates. Just to get the thing fired up 25 : 1 would be fine, it wont be doing any work when you start a tune etc, if it was mine I would be cleaning out completely the fuel system, from the tank to the carby and everywhere in between. Once you get it running and carby etc tuned you might then want to check point gap, as NormK has said above and I said in my first post it would appear you have a fuel problem (not necessarily the ratio you use to start), 2 strokes that have been left for a while do gunk up.
