Hi,
I have a brand new Victa Vantage fitted with a Briggs and Stratton 450 148cc engine. It has a problem starting from cold, if you remove the air filter and pour a small amount of fuel down the carburettor it will start on the first or second pull. When it does start the engine speed fluctuates up and down for about 20 seconds and then settles down to a constant speed. It then idles and revs cleanly from there on but can still need one to three pulls to start again when warm.
