please someone help me

[chef master]

ok i have a 1975 browning fishmaster 1 16ft aluminum boat with a mercury 85hp outboard (max hp for boat of that year) and my question/problem is when i go half throttle my boat planes out well but as soon as i go to full throttle the bow goes down to much in the water and stops plaining out thats with just me in the boat and or other people in the boat. I have messes with the tilt it dosent have power tilt so ive put the rod in all of the holes to see if any would make a diffrence and none have my prop is a 13x19 can anyone help me out???

 

[roscoe]

Re: please someone help me

Makes no sense.
One of those trim holes should have been good.
PRobably any of them SHOULD keep the boat running level.

Is the bottom of the hull damaged or dented in any way?

 

[chef master]

Re: please someone help me

Makes no sense.
One of those trim holes should have been good.
PRobably any of them SHOULD keep the boat running level.

Is the bottom of the hull damaged or dented in any way?

no not at all bottom is perfect condition, i think maby a diffrent prop might help but not sure

 

[oops!]

Re: please someone help me

agreed ...this makes no sense....

the boat is reacting like it is hooked just before the transom.

however, (and im guessing here) is this a stern lifting prop?

 

[5150abf]

Re: please someone help me

Is your transom solid, you should be able to stand your entire weight on the outboard and have it not flex more than 1/8'' or so, don't worry, under full throttle the engine is putting many times that weight on the transom.

Try to get a pic or 2 of the boat, get the engine and hgull from the side and maybe on of the back bottom, this is an odd one.

 

[Philster]

Re: please someone help me

Yep, we need pics of the engine mounted so we can see height, position, etc.

Wonder if this motor is too low/high or wrong length....

 

[chef master]

Re: please someone help me

how do i tell if its a stern lifting prop new to the prop world

 

[chef master]

Re: please someone help me

i went and pushed the motor back and forth this morning and it moved enough to know that the transom is rotting so im going to replace that in the next few days, i will post picts of it today will a rotton transom make the boat not plane out??? and ill post picts if someone could help me and let me know how to get the old transom out and a new transom in ive looked at it it dont look to hard but not easy eather

 

[Texasmark]

Re: please someone help me

i went and pushed the motor back and forth this morning and it moved enough to know that the transom is rotting so im going to replace that in the next few days, i will post picts of it today will a rotton transom make the boat not plane out??? and ill post picts if someone could help me and let me know how to get the old transom out and a new transom in ive looked at it it dont look to hard but not easy eather

You just nailed your problem when you noticed that the transom was rotten. At lower speeds, the twisting force on the transom is less so the top of the transom is not being pulled backwards by the torque of the prop all that much.

At high speeds, the prop torque is pushing hard forward which is pulling hard to the rear on the engine which pushes the top of the transom out. This is in effect "tucking your engine in" which is what you do with an engine when you want the bow to go deeper in the water which is just what yours is doing.

Fix your transom and be on your way.

Mark

 

[chef master]

Re: please someone help me

thank youill give it a shot and post back within a few days if it solved my problem

 

[chef master]

Re: please someone help me

how do i remove my transom board there is about 2-3 in on both sides that is aluminum covered i cant move without cutting and about 6-7 in from the inside bottom of the bot to the wooden transom





and when putting a new transom in how do i secure it to the aluminum

 

[roscoe]

Re: please someone help me

remove engine
remove transom cap corner pieces, I see one is missing, allowing water to enter and rot the wood
remove transom cap trim
remove all bolts and screws holding wood in
slide wood out
replace all screws, bolts, and rivets that were removed.


You would benefit from reading some of the transom replacement threads, here:


http://forums.iboats.com/forumdisplay.php?f=22



or here:

http://forums.iboats.com/Starcraft_Boats?boatid=243