Questions for the experts from a rookie

A friend of mine has a 1442 Alumacraft with a 15" transom and 20" sides. He has a Beavertail with a Honda GX390 motor that is supposed to get 13hp @ 3400 RPM and 18 lbs of torque with a 8X4 prop, year of manufacture around 2008. What speed should he be getting from this combination? Right now he feels like a decent headwind will stop any forward movement. He plans on installing a tach to see if he is running in the correct RPM range.

Any advice on things to check for better performance?

(edited: I had the make of the longtail wrong, its a Beavertail)

I have a homebuilt LT powered with a Honda GX340 on a 16x48 and it will push me my daughter and my dog along through the lake at 14mph. With a full hunting load it does slow me down significatly but I was still able to push up a strong current under full load 400lb+ at about 5mph. Checking the RPMs is the first place to start IMO. Maybe the throttle or governer is not adjusted properly. Be aware this is comming from a novice not a expert, but it is what I experienced also. Good luck.

1542 with Honda 390. I had a set up with no universal joint so I believe it was 13 hp. I was getting 13 mph. That was 2 guys,dog and decoys. That was a Thailand setup

Thanks for the feedback guys. We will see what the tach shows and maybe GPS it to check the speed.

I ran the same motor on a gdlt and a alumacraft 1448 rivited. Got about 14mph with no load. Went downhill real fast with any load at all. I now run a 20 honda on the same boat and will get 17-18 and it will carry a load much better.