Max II engine upgrade

[jwelch973]

I have an older Max II that came stock with a 12.5 hp B&S motor. I want more power so I would like to put in a 23 hp B&S. It seems that the 23 is a direct bolt in except for the exhaust. What are the easiest options for exhausting the 23? Is the only difference on the 23 the distance between ports and can I use the old manifold by modiying it? Any other issues with the 23 that someone can see?

[mad_max_500cc]

i have seen people cut and weld in an extension to the pipe between the ports to make a 14,16,18 hp vanguard exaust work for a 23 verry strait foward and simple

[coosaridgerider]

You can get a muffler that bolts to the engine on ebay for around $80 then run a pipe from the muffler out the back or side.That is what i am doing with my 25 kohler.

[greggv2007]

I purchased a muffler from Paul Sammut Silent Exhaust Systems Mississauga Ont. With shipping , was about 60-75 dollars. His ph.# 905-875-3790. I'm not sure but I think it was made for a 23 hp Briggs, but I have to modify the pipes to fit my 18 hp.