Help.... 9.8 will not plane a 12' jon boat

[Arrowhead74]

I bought a 1981 9.8 at a yard sale. A couple days ago I put it on my 12' alm. jon boat (rated for a 10hp). The motor starts easy, runs smooth and seems to have good power out of the hole. I can not get it to completely plane the empty boat. The trim is correct. The prop looks good, appears original and has P8 on it, so I'm assuming 8" pitch. It's sparking on both cylinders. The compression is 125lbs on each cylinder. I took the carb apart some, it was spotless. Any ideas would be appreciated.

 

[reddogg]

Re: Help.... 9.8 will not plane a 12' jon boat

Try shifting some weight forwards.

Red