[Luc]

My engine on my boxer 318 is on its last legs now and I'm thinking of maybe replacing the 18 hp vanguard Engine with something a little bit bigger.  Is this possible and will I get any better benefits from it?  The machine itself is perfect even tho its done  3400 hours now. If it is possible what size engine could I install if Iwanted to ?  Maybe thanks luc

[richie]

Throw a 20hp Kohler on it mate.  Better than Briggs Engines.  With the bigger engine you should get up to high water temp faster and have better constant heat.  The engine will cope better with the vacuum blower too.

[Luc]

Thanks Richie.  Would it be a fairly straightforward job or would it involve a lot of messing around with the blower and pump?
Luc

[terry barnes]

i suspect the exhaust header luggs will be different? and you may have to do something creative with the throttle cable i would definately check dimensions and clearances carefully before purchase

[richie]

It should be fairly straight forward.  If you want to make sure you have a perfect fit without having any adjustments then simply fit a 21hp Briggs & Stratton engine.

[AshWhite]

B&S 21hp is what's in mine

[nevil]

I replaced the vanguard engine on my old 4.0 with a kohler 18hp. So replacing the 20hp with a lower horsepower. It ran better in every way with the new engine. Hotter, bogged down less under load. Don't know why but I came to the conclusion Kohler engines are just better all round. Someone told me at the time (maybe on here) that kohler engines run hotter than B&S. The crank shaft size and geometry were identical in relation to two of the engine mount holes on the base of the engine. But two of them  didn’t line up meaning I could only bolt it to the frame through two of the four holes. I always meant to drill extra holes in the frame and weld nuts in behind but never got round to it. Didn't seem to cause any problems. Exhaust manifold and wiring was the biggest pain in the ass to sort out. 

[richie]

Id have a Kohler over a B&S engine any day.  So surprised that so many manufacturers choose B&S.  Must be a cost thing.  Kohler do run so much smoother.