By the time the 402XS came out Mercury was moving away from the "Direct Charge: Pistons, and building V6 motor.

Most 402 XS's that I knew about broke the sleeves around the exhaust ports. We kind of surmised that the exhaust was getting out fast enough and the engine developed enough heat to crack the struts in the ports.

My dad being the engine builder that he was, noticed a drop in RPM when the engine warmed up. HE SPENT MANY HOURS RUNNING MY MOTOR IN OUR TEST TANK.

In the spring of 1977 I broke Kilo records in 35 SS Hydro and 35 SS Runabout. I out ran BOB WARTINGER'S TIME IN 35 S HYDRO.

The one thing we didn't know was that gapped plugs would run in a surface gap motor. Clark Maloof taught me that after he beat me at the 1977 National. I could beat him o the turn but my surface gap plug would load in the corners, and Clark would drive around me...

Replacement locks were expensive and didn't last very long. Most 402 XS's got switched to 55-H's or D Motors, a fishing blocks were made legal and powerheads were everywhere, cheap!