Briggs and Stratton V-Twin with 2 barrel Nikki carburetor

[Douglas Lee]

Hello All,
I have an older V-Twin
Briggs and Stratton 407777 0128 E1
type 0128 E1 code 00607 YH
Hello All,
I have an older V-Twin
Briggs and Stratton 407777 0128 E1
type 0128 E1 code 00607 YH
It doesn't have the metal restrictor/swirl plate down stream of the throttle
plate next to the intake manifold.
I have seen these on some newer machines, and have one on hand.
Thinking about adding it to this assembly. What do you think?
From Briggs and Stratton Service bulletin 733, 10/05
Thanks,
Douglas Lee
*

 

[Auto Doc's]

Hi Douglas,

That is a restrictor that some models came with to limit the full engine output potential. They sell more of the same engine by juggling the horsepower numbers around. B&S has had multiple lawsuits regarding their advertised horsepower numbers. The same model engine could be on a cub cadet advertised at 23HP and then the same engine be on a John Deere advertised at 23.5HP or 24HP.

Leave the plate off is my advice.

Much of this also had to do with deck cutting widths. Wider techs needed slightly higher HP.

 

[Douglas Lee]

Thanks for the reply!
This is what and why . . .
It was running rich at lower rpm's
Installed that swirl plate today,
made a huge differance at lower rpm's,
no black smoke!
From Briggs and Stratton Service bulletin 733, 10/05
Douglas Lee
*

 

[Auto Doc's]

Thanks for the reply!
This is what and why . . .
It was running rich at lower rpm's
Installed that swirl plate today,
made a huge differance at lower rpm's,
no black smoke!
From Briggs and Stratton Service bulletin 733, 10/05
Douglas Lee
*

Hi Douglas,

Make sure to check your spark plugs regularly to make sure the engine is not burning too lean. If the porcelain is very white, it is too lean. Ideally, a light to medium tan color means a good mixture.

A lean mixture creates excess engine combustion heat and that is not good for any air-cooled engine. A slightly rich mixture cools the combustion temperatures down and ensures good power under load when it is needed most

I grew up riding and working on old Harley's and small engine equipment. We called it "reading the plugs" back then.