boats leans badly ..from new etec

[grub_ba76]

this is a question for my brothers boat....its a 7.5 alloy plate boat it originaly had a 135hp ficht ram....which was ok. but since putting on the new 150hp etec the boat leans towards starboard side(left) at high speeds the faster u go the worse even with 3 men standing on one side it leans the other way...boat is balanced with the gear(life jackets ect)...the same holes were used as the ficht 135hp were in.....nothings changed except putting on new motor...it has a stainless prop...dosent make no diffrence if its trimed up or down.....could it be that little trim tab(little fin above prop)....ask a few boat shops no one has a clue why....thanks graham

 

[Dunaruna]

Re: boats leans badly ..from new etec

Is there a doel fin fitted?

 

[Dhadley]

Re: boats leans badly ..from new etec

Does it lean toward starboard (right) or to the port (left) side? Does it have any sort of trim tab (hydraulic, electric or manual)?

 

[grub_ba76]

Re: boats leans badly ..from new etec

a doel fin?
ooops sorry......it leans to the left(port).....only trim it has is the motor trim(hydrolic)it has the trim tab on motor to correct steering.....its only 2 months old.....nothing is diffrent from last motor except hp....boat is 4 year old....tryed it with motor trimed right down and also trimed up....made no diffrence.......thank u for helping graham

 

[ezeke]

Re: boats leans badly ..from new etec

You might want to measure from the extreme upper corners of the transom to the gearcase to assure that the gearcase is centered on the boat. It can look fine at the mount and be off inches at the bottom.

 

[Dhadley]

Re: boats leans badly ..from new etec

Actually I wouldn't worry about it being centered on the transom but rather centered with the keel. Are you sure it's in the same place? Or is it lower? Both motors the same shaft length (both 20" or 25")? Where is the AV plate in relation to the bottom?

 

[DJ]

Re: boats leans badly ..from new etec

Actually I wouldn't worry about it being centered on the transom but rather centered with the keel. Are you sure it's in the same place? Or is it lower? Both motors the same shaft length (both 20" or 25")? Where is the AV plate in relation to the bottom?

Agreed.

I bought new boat once that the OB was 1/2" off center (cockeyed off perpendicular to the keel)). Boy, did that boat handle-weird.

Otherwise, the "trim tab" may be the issue, or the engine is too deep in the setting.

 

[Dhadley]

Re: boats leans badly ..from new etec

Yeah, I got caught up with that years ago. Rigged a very popular (for that era) boat and was very careful to center the motor and guess what? Found out that from the keel to each side was 3/4" different. What a mess that was. Found a few since but not many.

There's a Lake-N-Bay around here that the motor is crooked on. They leveled the boat on the trailer and laid the jig on the top of the transom & drilled holes. Yep, it's not level.

 

[SuzukiChopper]

Re: boats leans badly ..from new etec

Don't want to highjack this thread at all but after reading this a light went off in my head. My boat has a tendency to pull starboard and I'm thinkin' I should check my rigging! Always just assumed my OB was mounted correctly. Thanks!

 

[ezeke]

Re: boats leans badly ..from new etec

To SuzukiChopper: when the pull is to starboard, turn the rear of the trim tab (above the propeller) to starboard in small increments until you adjust satisfactorily for average running.

 

[SuzukiChopper]

Re: boats leans badly ..from new etec

To SuzukiChopper: when the pull is to starboard, turn the rear of the trim tab (above the propeller) to starboard in small increments until you adjust satisfactorily for average running.

already been through that. Thanks though!

 

[grub_ba76]

Re: boats leans badly ..from new etec

yas could be on to somthing here......ok ill start from when the boat was new.....has i said had a 135 hp ficht ram....all was good.....the gear box blow up....so had a new one fitted....THEN it stated to cavatate badly....trimed up or down....the prop would get air and had bad steering (yes the leg was 1 inch shorter)the cav plate was level with bottom of boat when trimed right down....but then after 3 trips the computer blow up....so he replaced with the etec...which got rid of the cav proplem(cav plate now sits approx 1 inch from bottom of boat) and the boat perferms much better with steering ect....but at higher speeds and faster u go it leans........yes it looks very centre(havnt mesgured) but in same holes as ficht ram was in and the ficht didnt make the boat lean......if it is of centred it would only be millurmetres....do yas think that would cause it?....thanks for the replys...graham...ps both motors were fitted by evenrude dealers

 

[Dhadley]

Re: boats leans badly ..from new etec

You mentioned the AV plate sits 1" from bottom. If it's 1" down, it could be a problem.

 

[steelespike]

Re: boats leans badly ..from new etec

If your not experiencing ventiltion the motor is probably too low.
Raising the motor should improve handling,speed and efficiency.
A sofisticated prop ss or something like the Hustler turning point al. can further improve height and handling.

 

[grub_ba76]

Re: boats leans badly ..from new etec

dont people read what u write.....it sits approx 1 inch from bottom of boat as its surpose to any less and it would cavatate......yes its trimed up right and handles excelent....triming and handling isnt my proplem its the way the boat leans....not pull to one side ....its like having 5 people standing on one side.....been around boats for many years...i know about the trim ect.....my question was about boat leaning.....the faster u go the worse the leaning....yes it does go better trimed up.....the motor is hooked up to a computer.....so we can see what fuel is being used,oil, temp ect....so yeah thats how we work out the best spot to trim to......as u said trimmed right has lighter steering better fuel and oerfomance....thanks alll ...graham

 

[steelespike]

Re: boats leans badly ..from new etec

Don't get so worked up. "1 inch from the bottom"could be below or above.Most are good even with or up to about 1 inch above.I would say that 1 inch below is the exception."A 7.5 Alloy plate boat doesn't exactly give us much help.Is it considered a full planing hull or semi displacement or full displacement?More detailed info might help.Its normal for prop torque to create a tendency to lean and some V bottoms will try to run on on side or the other especially when working against a wind.Some props create stern lift some bow lift."Nothing changed" does that mean the prop is exactly the same
brand,style and material?You might try the prop from the 135 if it will fit?
According to your info thats probably the only difference.Obviously not the right pitch but it could be a clue.

 

[SuzukiChopper]

Re: boats leans badly ..from new etec

What about the skeg? Is it straight? I would think that if it's bent to one side or the other, or even twisted it's going to create an awkward force that might push the boat, especially if it's a v-hull style boat.

How about some pictures of the setup? From directly behind and motor trimmed down and from the side. Without seeing the boat itself, what's attached to it, how the motor is mounted, etc... it's very hard to give any concrete advice. Right now it's like stabbing in the dark hoping to hit something.

 

[ezeke]

Re: boats leans badly ..from new etec

If you have a NFB steering system, you can't feel the pull to starboard or port, so you would not be aware of the difference that adjusting the trim tab would make. Try setting the trim tab to neutral (0) and adjust slowly from there.

Most people have not given a great deal of thought to the trim tab, but its effectiveness is due to the fact that it is behind the propeller, deflecting water driven with great force. For example, you can offset the effect of a badly twisted skeg with a small adjustment of the trim tab.

 

[grub_ba76]

Re: boats leans badly ..from new etec

sounds like yas know what yas a talking about.......its a v hole with forward stand in cabing....live bait tanks.....150 litre fuel at back....it does either 59 or 69 kilometres per hour.....yes its a diffrent prop....its bigger then the 135 since the hp is bigger.....my brother has gotting the right pitch for that boat(he went thru that with 135hp)....its getting i think he said 5600rpm give or take a 100rpm.....its build out of 5 mil bottom, sides and top....it gets up and goes well.....can only use full throttle in calm waters......the oceans around here u very rarely get over half throttle.....its build for fishing only with cab right up front and open space down the back......has i said old motor was good untill the gear box blow up and the leg that was fitted was shorter (i know strange hey) which made this boat dangers ...it would cavatate over waves....and when goin down a wave u would have no steering.....with new motor no cavatation.....and handles a 100 times better goin down waves.....can now travel faster down them and have full control....the motor is attached to a pod on back of boat which was made with boat(custom made predator boats)....the pro fishing men use these boats....has 4 times more ribs then most....ribs are spaced about 200 about and are fully weld to floor which is sealed.....so i would take that its heaver then most....its a full planning boat.......i think steel is on the right track....prop torque twisting the boat.....more throttle more twist...is there any way around this? and do yas think its that?....thanks again for the help....graham...ps the trim tab is set straight havnt tryed that yet....i wanna get ideas before we go for a run....sorry im not sure what a skeg is..

 

[ezeke]

Re: boats leans badly ..from new etec

The skeg is the triangular extension below the cylindrical part of the gearcase and before the propeller; it is there to protect the propeller from striking underwater objects when underway.