Briggs 8hp flathead carb compatibility
- Thread starter Bigcat4570
- Start date
I've put a 26mm Mikuni on a 2.75hp flathead and it's totally brought that engine to life. Finding a manifold to fit both carb and block can be a big challenge -- tho I've also had success there with combinations of what's available on Amazon (castings, silicone hose). Note my flathead's intake is only about 21mm, but matching carb size to intake size proved to limit performance. Just my two cents, and not sure this is what you're asking for.
I started with a 22mm Keihin (Mikuni type), and was able to tune it to a great level of performance, although I also learned through much tinkering that the jets I had to use to get there were pushing the 22's limits and it was having a hard time maintaining idle. That idle problem went away with the bigger carb output. It also makes the engine roar more than the 22 did. Keep in mind I'm a beginner and learning through trial and error. Others on here might recommend different. But my point is I think you want to match the venturi body to the block intake, rather than matching the output port to intake port. Not sure what size intake on an 8hp Briggs as I only know 2 and 3.5hp's to date.