I have just put together a 12 foot Jon boat with a 42" bottom. It is powered by an Arctic Cat 500 twin 2 stroke motor and a 36" 4 blade propeller. I put it in the water for the fist time to try it out and I was really let down. When running in shallow water the back of the boat went down and the front of the boat road a little high. Top speed was about 5 mph. And boat never plained out. I am new at this and I am shooting at the hip.could anybody help me out with this problem?

Hey Jason welcome to the forum. Can you maybe give a little more info as to hp, rpm and pitch and I'm not familiar with that motor but if its a two stroke the usually need reduction drives to let them get in there power range. Also a stupid question but maybe the prop is backwards? Sounds like you may have to either trim your motor to blow down a little which will raise the back up a little bit or maybe place your self a little forward to help even the weight. The bottom may be a little narrow to help plane out but it has been done. Also pictures if you can says a thousand words.

Again welcome to the forum and keep trying it gets addicting :)
Steve

Hi Jason,
I built and ran a 14" jon boat with a 40hp two-cycle JLO snowmobile engine for quite a few years and while it did what I needed (i.e. get me back into the shallow hunting grounds) it never performed up to my expectations as far as speed and it was hella-noisy. This was due to the high engine rpm and the fact that the prop tips were approaching, if not exceeding, the speed of sound which makes it very loud and inefficient! I would recommend running a reduction drive with yours in an effort to slow the prop and make it more efficient (and quiet). Just my opinion ... I'm now in the process of building an airboat with a continental 4a084 engine and running a reduction drive.

I agree with what Steve said, that motor needs to turn at a faster RPM to make it's power so it's not turning the prop at the right speed. Most likely you are right at the verge of getting on top of the water and your bottom is pushing all the water making your front end come up. You may be able to get it going with a reduction drive depending on the boat weight and your weight. That bottom is a little narrow for a mini airboat hull. Ideal is 5ft of bottom but a minimum would be 48inches. A 36 inch prop would be for around 8-10 HP depending on what the pitch is if it is turned at the right RPM which is around 3100 RPM. I never say no, I wouldn't give up on it just yet.

Also, at least put your state in your profile, someone may be close that could help you. Welcome to the site!