8hp briggs flathead

[minibikes4life]

recently acquired an 8hp briggs flathead (1" shaft), model# 190432.

looking into hopping it up a little, nothing crazy, but wana make it as solid as possible.

so im thinking carb swap using the existing manifold, and modifying it by cutting off the angle drop and rubber mounting a carb to it.

although if there was a better manifold to use, i would be interested.

if anyone knows of a header that would work, and some billet components, please let me know.

 

[cheezy1]

The biggest problem with those motors is the crank. Years ago we use to do mods to them and the cranks never lasted when you pushed a higher RPM. Sadly the cranks would let go before the factory rods would. If your building it for torque and lower RPM applications...they are an awesone motor.

 

[minibikes4life]

what kinda stuff did you do to yours when you ran them?

 

[cheezy1]

Milled head..different carbs...removed something I cant mention...friends Dad use to make us cams..etc.

 

[minibikes4life]

its a shame the cranks aren't more durable, thanks for the information.

 

[cheezy1]

You welcome. But like I said...lower RPM and they will run forever.

 

[kc57]

Here is a setup I have on one of my bikes. Mounted an adapter plate, So I could attach a shortened 10hp Tecumseh intake. A 26mm mikuni fit the tecumseh intake with just a little filing. I had to make up a cable for the throttle. It was well worth the trouble. The performance with the stock carb was disappointing . This really made a huge difference, the throttle responce is amazing.

 

[Confused1985]

What jets did u use for the 26mm Mikuni?

 

[kc57]

I used the jets that came with the carb. I moved the needle down 1 notch