new power

C

cut plug

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just put on a 2003 tohatsu 115 on my 83 18' C=Dory. I dips to left at speed. Any ideas to remedy this? Trim tabs etc... Thanks, Rob (cut plug)
 
One thing to check or adjust might be the trim tab on the engine itself. This may look like a little metal "wing" under the anti-ventilation plate which you can adjust from side to side to compensate.
 
cut plug":1efcl4oi said:
just put on a 2003 tohatsu 115 on my 83 18' C=Dory. I dips to left at speed. Any ideas to remedy this? Trim tabs etc... Thanks, Rob (cut plug)
Click to expand...

Hello CP

Congrats on the new motor. The prop's right-hand rotation is causing a little 'steer' effect. Not uncommon.

To fix it, try adjusting (i.e., rotating) the tab hanging at 12 o'clock above the prop as viewed from the rear. It looks like this...it is sometimes also a sacrificial anode
TOHATSU-TRIM-TAB-ANODE-50-60-70-90-115-140-2-STROKE-OUTBOARD-ENGINE-3B7-60217-1-180954177670.jpg


dave
 
Do you also find it harder to turn the steering wheel one direction as opposed to the other at some speeds? If so, it's very likely the engine tab.

If you're not familiar with adjusting that engine tab, you may want to look at it closely, and read up a little in your manual. The adjustment can be counter-intuitive for some folks. The placement of the tab is behind the pivot point of the outboard as the outboard is steered. As you stand behind the boat, turning the trailing edge of the tab to port will make the engine and its prop swing to starboard, which will make the bow swing to starboard, as well. Think of it as a rudder for the prop, not for the boat. Try small adjustments at a time. It may be hard to find one setting that fits all speeds. I usually adjusted the tab so as to be as near neutral as possible at my normal on-plane cruising speed. (If I've got this all wrong, I'm sure I'll hear about it. :lol:) Good luck!
 
My old Sea Ray would dive left at speed if the outdrive trim was fully down. This was a bit scary! Try adjusting your outdrive trim up, to a position where the ventilation plate is parallel to the bottom of the hull. With the boat on the trailer, adjust the trim to be parallel and note that position on your trim gauge. This "neutral" trim position can be a useful reference in learning to drive the boat in various sea conditions.

That new engine is a substantial amount of power for that size boat!
 
Darkwater":2bdv9x21 said:
My old Sea Ray would dive left at speed if the outdrive trim was fully down. This was a bit scary! Try adjusting your outdrive trim up, to a position where the ventilation plate is parallel to the bottom of the hull. With the boat on the trailer, adjust the trim to be parallel and note that position on your trim gauge. This "neutral" trim position can be a useful reference in learning to drive the boat in various sea conditions.

That new engine is a substantial amount of power for that size boat!
Click to expand...
--->Bolding and underline is mine..Harvey

It may be that Darkwater is onto something there. Seems to me like that would be like putting a V-8 on a go-cart. Just for comparison, that is 1/3 more power than I have on my 22 Cruiser. Curious how you came up with the HP choice? Do you have trim tabs on your 18? And when you say "..at speed" What speed are you making?

Harvey
SleepyC :moon

JC_Lately_SleepyC_Flat_Blue_055.highlight.jpg
 
It's a torque reaction. The prop rotates to the right, viewed from behind. The torque reaction to turning the prop tries to rotate the motor and the whole boat to the left. (The left side of the boat is being pressed down while the right side is being lifted.)

You have more torque applied to the hull than the hull can handle.

Trim tabs could help.

PS: Make sure your transom is in good shape as the motor is trying to twist itself off the boat.
 
Larry H":3tiwhdnx said:
It's a torque reaction. The prop rotates to the right, viewed from behind. The torque reaction to turning the prop tries to rotate the motor and the whole boat to the left. (The left side of the boat is being pressed down while the right side is being lifted.)

You have more torque applied to the hull than the hull can handle.

Trim tabs could help.

PS: Make sure your transom is in good shape as the motor is trying to twist itself off the boat.
Click to expand...

Right on Larry. Re: "Newton's first law of motion" said it best in the 1800's -- something like this:
For every action there is an opposite and equal reaction. Therefore, the action and force in turning the prop to the right means the motor housing absorbs the equal "reactionary" force to the left along with the transom/boat.
 
I'd love to see pictures of the elusive 18' angler. I have seen the Toland 18'8 out on the water, but not sure I've ever heard of an 18 angler before. It sounds really cool!
 
My 1983 22' CD tipped to the left with a 115HP Johnson at high speeds. It scared hell out of me the 1st time.
The little rudder on the lower unit and keeping my throttle pulled back a little fixed it.
Good luck.

Jack
 
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