I need some help setting up my 12' Bullet

**Spaceman Spiff** · 04-22-2025, 10:40 PM

Originally Posted by Mark Poole ModVP

I know the mentality with Scream and Flyers is always more motor more speed. The problem comes when you put too heavy a motor on a boat that does not have enough bottom. That short little boat with a long shaft 48 is unbalanced and the bouncing problem is because the hull is not long enough. This is a pic of a boat I used to have. It was a copy of a Kennedy Craft. It was 15 ft. long and probably weighed 250lbs. With a jackplate and a stock 30 Johnson with an SST prop it topped out at 38 mph rock solid with level trim. If I would have modded the engine and put a teenager in it I am sure it would have run well over 40. Less engine, a longer hull and the right set up can result in more enjoyable ride.

Well, I got lucky and found a cherry (no nicks and tons of gloss) 1983 Mercury 40hp. It's listed at 145lbs and that's about 45 lbs less than the 48SPL. With a 17P prop that should be considerably better performance than the 35hp, and better balance than the 48. The Bullet is rated for 40hp MAX.

**Spaceman Spiff** · 04-27-2025, 09:18 PM

I got this 40hp on there and it is just bouncing like crazy above 20mph. This is really starting to piss me off. I even put a 50lb bag of pea gravel in the bow. All I can do to redistribute weight is to put my battery up under the dash and maybe push that gravel further forward. But it just seems like that is just a band aid to cover up the real problem. And I have no clue what the real problem is. This motor is only 145 lbs and is raised maybe 1.5". I haven't shimmed it yet, but it is on the bottom trim hole. No jack plate or whale tale....
I built an 11' Minimost in 2020. Very similar hull with less vee up front and a flat stern. I had a 50hp Mercury 4cyl on it and that thing was just glued to the water. All that weight in the back and a shorter hull and no problems. I even sat further back in that one. It would do 40mph with very little bow lift. I was kind of afraid of stuffing it. I sold it because it wouldn't turn for crap. With this Bullet you can just dump the sheer clamp in the water and turn on a dime. But I have to get it to stop porpoising or it's out the door. Please help.

Stephen

**Spaceman Spiff** · 04-27-2025, 09:24 PM

It kinda looks tucked.

**Spaceman Spiff** · 04-29-2025, 02:54 PM

I managed to cure the bouncing by moving the gravel bag all the way up to the front of the bow and putting the gas tank under the bow as well. Also I shimmed the top of the motor back 1/2" from the transom. Now there is no porpoising, at least to my top speed of only 27mph. My motor stops revving at about 4600rpm. I think I just need to adjust the throttle cable. With a 13P prop(the only one I have at the moment), I should be able to spin it over 6000rpm.

But set up like this, I notice that the steering has become more sensitive to input. And it seems to list in the direction I turn the wheel before actually turning the boat. That's kind of a bummer because it was super fun to turn before, and now that's diminished a bit. Is that likely due to more of the keel line being in the water?

**Spaceman Spiff** · 04-30-2025, 08:03 PM

I got the motor to 5000rpm and only hit 28mph. And it steers like chit. So this motor is a fail, as is the boat. I'm going to put the Evinrude 35 back on there and sell it. At least I got 30mph out of that and had good steering. Thanks for the help. I still have my Tunnel to play around in.

Stephen