I have a question on the carb on my Lauson Sport King single cylinder. First off , is there a gasket between the top plate and bowl Like the Mercurys? I don’t recall removing one. And Second, there is a small notch or slice on the top plate edge. Is that my vent for the bowl? If there was a gasket in place, I think it would restrict the vent. Thanks , Matt.
The lauson model 410 carb is different from the S-300 series motor. The 410 carb needs a gasket to prevent gas from seeping out. That little notch needs to be kept clear for venting. The float/inlet needle and seat needs to be clean and smooth to prevent carb flooding. This motor uses 30 wt non detergent oil (about 8 ounces I think). Set your points at 0.020″, and your spark plug at 0.025. I use the John Deere cornhead grease in the gearbox. These are good running motors that idle very slowly. Good luck with yours.