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DYNO TESTING A 13HP HONDA

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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,738
Location
AMES, IA USA
DYNO TESTING a Honda GX390 Stock is 11.7hp/13hp@3600rpm. Looks like a Stock Carb with a better Air Filter with just a Header Exhaust and run up to about 5000rpm.
https://www.youtube.com/watch?v=sTBq3bRRQqE

Some Comments below the Video.
The Timing is Advanced and the Cylinder is finished with Torque Plate, but you must remember that it is running a Header and less Restrictive Air Filter as out of the box they are 11.7 net hp.

UT1 engines have .045 Composition Head Gasket and UT2 have .010 Steel Shim Gasket easily seen from looking at where the head joins the block.

This is the old style engine(UT1) and requires up 2 jets for Header and Air Cleaner change, the new engines (UT2) are perfect for Headers out of the box with 13-1 a/f ratio.

Idle was 1500rpm!

Made 11.7hp@ around 2500rpm.

Made 13.0hp@ around 2785rpm

Made 17.0hp@ around 3500rpm.

Made 18.2hp@ around 4900rpm.
 

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