I need help getting mine back together.....I took off the old carb (Nikki) and want to buy a new Walbro....are there step by step instructions somewhere that can help me do it right? Also, after I got the carb off I noticed a flat rectangle box with a rubber looking boot (looks like the rubber cap off the spark plug) hanging off of it....I pulled it off and it looks like a round diafram on the flip side of it....I can see the push rods and springs in the motor when I took this part off....what is it?
That valve spring cover is the crankcase breather. Basically, it is what a PCV valve is for a car engine. Back when I was in the mower business, that tube attached to the carburetor on a Briggs. On some engines it was just open to atmosphere. I've been out of the business for more than 20 years, so my points of reference are a bit dated.
This is probably closer to being correct. I am picturing the old 190700 and 251700 series engines, which actually did attach directly to the carburetor.
