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should this boat run dry

J

josh_2562

Well-known member
I picked up my first a/c engine boat to day. It's a 11' gore hull with a 125 hp lycoming engine.the boat has frog spit on the boat but it old. It's turning a 68x30 prop up to 2900 rpms. Should this little boat run dry? As of right now it will not. Could it need a different prop?

I took the boat out for a test run and if I get on the gas hard then let off it starts to hop. it has a trim tab on the back should I move it down some? Thanks for all the help Josh
 
Most likely not. How much do you weigh and how much does the boat weigh. Looks like you will be doing alot of pushing and pulling if you try to run dry alot. You might get a little more out of an adjustable carbon prop, but it's still a 125 hp. You will get Lucky here and there. Just a little water and you will be good to go.

That pushing gets old fast. You will figure it out real quick. Good luck and enjoy!
 
I'm a big guy 280lbs. I pulled up on the bank and it wigged it's self off. But it would not move on dry in the yard.
 
I had an 0290 angle valve on a 12'' Gore and it would run the hill
ok after the dew fell, but on the bone dry you needed to see water
not to far ahead or you were up shi@#$t creek. of course that was
before any one ever heard of poly, or frog snot. I used to hang a
comalong from a tree limb and lift the bow eye so I could wax the
bottom with car wax, and it was great for a couple of hours.
 
my dad had a 125 on a 12'grasshopper hull,did good in the shallow water but he tore it up trying to go where he shouldn't have
 
What should I do about the porpoising. If I hold it about 2200rpms it's fine, but if I run it up to 3000rpms and let off the gas it starts hopping bad.
 
don't let off :D

just kidding

sounds like you have alot of weight forward



edit try putting gallon jugs of water in the back to see if it makes a diff
as you let off there is no more push so the front wants to sink then the buoyancy of the boat takes over and makes it pop back to the surface and repeat cycle see what i'm saying? if adding more weight to the back temporary this will prove out and give you a idea of how much you you need to move (like the gas tank etc.)

good luck
 
I made a trim tab from a pice of 2x2 aluminum angle
mounted in the center of the hull, it worked great, but
but made the torque roll more noticeable . I cut it in
half and put the two pieces about 3' apart and it was
great.
 
it has a old trim tab on the back,But when the guy brought it to my house it was on the trailer on a 5th will trailer. When we rolled it off the trailer it hit the trim tab and might have bent it. should I move it up or down?


would a 4 blade warpdrive be good on this boat? Thanks for the help
 
The one I had was just a piece of 2x2x1/4'' angle ( preaty stout stuff )
and the angle would have been 90 degrees from the slope of the transome.
I never tried to adjust it, just split and moved it.
 
I'm going to take the boat out tomorrow and play with the trim tab. When the boats on dry ground it left the back of the boat off the ground but won't move. Thanks for all the help
 
If it is lifting the back of the boat on dry ground then you need raised the back of your motor. You can do that by adjusting and shimming your motor mount. Once you do that your boat should run the hill alot better. Best way to tell if you got the motor pitch right is when your just above cruising speed the boat will begin to porpoise. This happening while your foot is still on the gas holding it steady.
 
I was looking at the rubber mounts and they are shot. I'm going to replace them and see if it helps. Thanks for all the help
 
josh_s_new_boat_003.jpg


josh_s_new_boat_002.jpg


josh_s_new_boat_001.jpg


Here's some pics of the boat
 
Ok I took the boat for anther ride. If I stay on the gas it does not hop, but as soon as I let off it start hopping till I slow down. I think it riding on the nose.

I'm new to this but could it be pushing the front down in the water then when I let off it pops up making it hop.


I leveled the boat and the engine is down in the back(prop end) about a 1/8 of a bubble on a 4 foot level.


I'm going to lift the back of the motor about 1/2 a bubble like cont520 told me to try.
Thanks for all the help guys
 
you want the rear of the engine to be up about a 1/4 bubble or so, that will lift the nose.

cont520 has you straight :D
 
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