I currently have a 13hp GDlt on a 1436. I am looking to upgrade to a 1542 or something similar. I know I will lose what little bit of speed I do have by going to a longer/wider boat. I am exploring my options now. Would it be more worthwhile to do some mods or just swap the engine out. Can't really afford to just buy a whole new engine so I am considering buying a 16 or 20 hp engine and putting it on the GD frame that I have. What are everyones thoughts and opinions? Any advice is appreciated.

Steve
Blacklabde

I have a 13 on my 1442, I can run 15 with the boat stripped down with just me.

Heavy heavy two man huntin load its subplane 10 mph

When i get the funds I will put it on a 15x40 built for a mudmotor and maybe swap out the power head for a 23.

You can do serveral mods to these single cylinders with go-kart mods (cut out governer and rev limiter, deck heads, port and polish, carb, exhaust ect....)

If you decide to go the engine swapin way pay attention to crankshaft heights and u joints.

I have been looking at a bolt on kit for the gx390 on affordablegokart.com. It comes with an airfilter/airfilter adapter and a straight header. It says with the governor removal and this kit it will really wake up a gx390. It also says I would probably need a larger main jet. The kit costs 70 bucks. I have the resources and ability to do most anything besides headwork myself. I am just worried that I am going to dump a bunch of money into the motor, and still not be enough hp to push 2 to 3 guys and a load when duck hunting.

Steve

a larger block will really be your best bet, you could most likley get that 13 to make 20+ hp but you run the risk of blowin it up.

Blowing the motor up is definitely in the back of my mind. I think I am going to try the bolt on kit and either rebuild the carb and put a larger main jet , or just replace the whole carb. Then go from there. Removing the governor makes me nervous for sure.

Anybody have any experience with a straight header/exhaust system. I am for sure going to be louder, but with a silencer or muffler it should bring it down to a "reasonable" level.

Steve

you might be surprised to know that it might not be any slower just try it