Nikki 791230

[CLStout]

Governed engines are a slightly different beast.
In a race engine you look to get a steep increase in the power curve for maximum acceleration followed by a flat peak torque line so all you have to do is keep increasing the revs and you power on to victory.
But these engines are governed, at 3600rpm, they spin quite slow compared to a race engine doing 3 to 4 times that speed.
So much of what you would do to get more out of a race engine produces little outcome on a governed engine.
The mower factories work out the power requirements of a mower then add 20% to 25% to that figure then go looking for an engine .
Briggs rates engines in 1/2 Hp incriments and they do this by detuning the engine down to what the mower makers want.
The first 2 numbers in your engine model is the capacity in Cu inches which in your case I am guessing is 44 ( 742cc ) which is a 26Hp engine .
Briggs chokes it down to make a 24 Hp , 22 Hp & 20 Hp engine.
Back in the Pre EPA days the simplist thing was to fit different main jets, now days they choke down the engine & fit different governor springs.
AFAIK the jet sizes do not change within a capacity group.

So, the restrictor plate is what's used to detune the engine to the desired HP?

 

[StarTech]

Yes it is limit the overall HP of engine. Just of NASCAR running restrictor plate races where cars are to a certain max hp.

Now Briggs does use a swirl plate to provide optimization of the fuel fuel/air mix. They also can use a restrictor gasket to limit the HP. Most times I just leave out the restrictor gasket.

 

[CLStout]

Can you advise which is which? The restrictor plate is the metal one with the eyebrows? I don't know if I have ever seen the swirl plate.
Thanks

 

[StarTech]

Will someone please with sugar on top fix this damn website.

 

[CLStout]

Thanks for the reply. I don't have the restrictor plate, but I do have the swirl plate. I really appreciate your help with identifying the 2 plates in question.

As for the website, I agree. It's acting up badly.