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Kevin N Bayliss

Hi John, I made a new crankcase door for the right hand side, this houses the Boyer system and I also have a gear driven oil pump from the end of this housing. The system is 6 volt. after more investigation into the poor running I have found that both cylinders have a knock / bang when the engine is running,( if you hold your hand on the cylinder wall). After speaking to several people I believe that the wasted spark that the Boyer produces is actually firing the Scott engine when at or close to bottom dead center, this also looks like it’s causing the big end rollers to skid rather than turn as I have slight wear marks on the rollers, (new coming). also it would account for the noisy exhaust. The residue around the pistons and bores and even in the crankcase wells seems to be quite dark/black colour. This would suggest all the fuel not being burnt properly as if very rich and the cylinder firing twice per revolution. Maybe it’s the timing on the Yamaha that stops this happening? So next step once the engine is back together is to remove the Boyer and fit twin points and coils and see what this does then. will keep you posted. Kev