New motor need help on set up

[lucky13]

Ive got this 13' 4'' St Martin I put 85hp Yamaha and jack plate on it couple of days ago. It had a ss 17p prop and the battery and gas tank behind the seat. I moved the battery and gas tank to the front after I ran it once and then got a 24p laser 2 prop. Its running great up to 52 mph but after that it starts chine walking. What can I do to keep it strate. Trim tabs?

[Rusrog]

I'm guessing that the boat doesn't have any sort of a pad keel does it? If not that may be a bit of a chore. How is the wheel torque? Is it trying to pull to left? How high is the motor in relation to the bottom of the boat? Watch your water pressure guage and come up on the motor an inch or two.

[lucky13]

There is no pad and i dont have a water pressure gauge. I cant feel any torque on wheel and its not pulling. When the motor is all the way down the prop shaft is 4'' under the bottom of boat. Can i go much higher than that?

[marinetech51@earthlink.net]

There is no pad and i dont have a water pressure gauge. I cant feel any torque on wheel and its not pulling. When the motor is all the way down the prop shaft is 4'' under the bottom of boat. Can i go much higher than that?

The cavitation plate on the lower unit should be somewhat even with the bottom of the boat as a startin point.

[JohnsonM50]

The cavitation plate on the lower unit should be somewhat even with the bottom of the boat as a startin point.
Long ago I put a 50hp OMC twin on a 15' aluminum boat. It wasn't exactly chine walking [they were round] but it would jump & twist needing the wheel corrected back-n-forth to maintain direction. A Stingray 'whale tail' cured it enough so it would jump in a straight line. Later I raised the motor & cut the tail down a little. This went 45-48mph & handled well once right. Good Luck.

[Smokin' Joe]

Ive got this 13' 4'' St Martin I put 85hp Yamaha and jack plate on it couple of days ago. It had a ss 17p prop and the battery and gas tank behind the seat. I moved the battery and gas tank to the front after I ran it once and then got a 24p laser 2 prop. Its running great up to 52 mph but after that it starts chine walking. What can I do to keep it strate. Trim tabs?

Start by strapping the downhousing to the transom with bungee cord, and check the steering for play. Eliminate as much play as possible. You need dual RideGuide as a bare minimum. With cable and pulley steering there's no play, with RideGuide there's always play, and if you aren't an expert driver you'll feel it. Also, replacing the hand throttle by foot throttle will allow both hands on the wheel, where they should be. In addition, a V-bottom without pad is a bad design, is not as stable as a pad boat. Cavitation plate should be well above the boat bottom, with a long shaft motor you should be able to run at least a 23-24" transom height. I recently drove a 14' Allison bass boat (pad bottom, optimal design) with long shaft Merc 700, not jacked up much (maybe 24"). Couldn't trim out w/out danger of loss of control (about 53 mph) b3cause of play in the RideGuide.

[lucky13]

That sound right I will have to try some of these suggestions. I hate to change the stering, its not a race boat but do want to go faster. Will trim tabs not help. I have a set of trim tabs and a bobs stablelizer plate, but didnt wont the drag.

[Smokin' Joe]

That sound right I will have to try some of these suggestions. I hate to change the stering, its not a race boat but do want to go faster. Will trim tabs not help. I have a set of trim tabs and a bobs stablelizer plate, but didnt wont the drag.

Tight steering and two hands on the wheel, not trim tabs.

[JohnsonM50]

That sound right I will have to try some of these suggestions. I hate to change the stering, its not a race boat but do want to go faster. Will trim tabs not help. I have a set of trim tabs and a bobs stablelizer plate, but didnt wont the drag.
Smokin Joe's very likely to be on the money, the non padded V wants to lean off into a turn so play will work against you. Trim tabs, whale tails are band aid fixes & a wild guess. Even if you get both hands on the wheel that wont compensate much for play, A dual cable will minimize it. How much faster will it go?

[lucky13]

If i keep both hands on the wheel I can keep it strate with a lot of steering for a while. Its picken up speed the whole time Im triming out till it gets to scary and i back off. It seems like I could 60 mph if it would stay strate.

[mayflyIII]

If i keep both hands on the wheel I can keep it strate with a lot of steering for a while. Its picken up speed the whole time Im triming out till it gets to scary and i back off. It seems like I could 60 mph if it would stay strate.

Sorry, my son logged in, I deleted this post.
SJ

[Smokin' Joe]

If i keep both hands on the wheel I can keep it strate with a lot of steering for a while. Its picken up speed the whole time Im triming out till it gets to scary and i back off. It seems like I could 60 mph if it would stay strate.

Listen, without tight steering you don't need to run 60 mph, 'scary' is not what you want.

One of my brothers has a stern-drive non-pad V with tight steering, I can hang the boat
on the tail, 63 mph, and I don't like the way that it feels. Without tight steering I wouldn't try to run it fast, period.

[Doubleeagle]

First of all there is nothing wrong with a full v bottom and you do infact have a pad it the outside of the two strakes I doubt very seriously at 50 to 60 you have run out of bottom
You do want to make sure your steering tight Secound you should install a w/p gauge a speedo and a tach My hunch is you have very little seat time in the boat I am thinking you start up on the trim button and just keep going you have the right idea going tell you feel the problem then down just a tap let it stablize You said you cant feel any tourque on the wheel you should feel some so once its stablized turn wheel against torque of the motor until you feel it in athe wheel then bump trim up you will fill differance in pressure if it starts to drive boat off the strakes a quick movement against tourque will general hold it up on the pad (strake) A easy way to see what this should feel like is to drive boat against current or into the wind with the nose about quarter into with the non torque side against the current or wind (acts like a training wheel and will let you feel what its like) I think if you get some seat time and a feel of what the boat is doing you will master it Two other suggestions you are probley triming to quick and to high If the engine is to low or to high props weight etc I think you were wrong moving weight forward I would go back to orginal set up and spend some time getting to know the boat