Trim Tabs???

[Danny in CO]

I just bought a 1986 Mach I Challenger 19' with a 5.0L OMC Cobra about 2 weeks ago. I've had it out once since. When I had it on the water the driver's side of the boat would come up way more than the left. Would trim tab help resolve this and make it ride more evenly?

Thanks,
Danny

 

[Solittle]

Re: Trim Tabs???

Yes if hydraulic. They will also allow you to adjust how it rides under different loads and ride conditions.

 

[Boatist]

Re: Trim Tabs???

I agree any type of adjustable Trim Tabs would be able to correct a lean to either side. Also can adjust the boat for the best safe ride in any conditions.

Does it lean when stopped in the water? If it does then you need to adjust weight in the boat and make sure the bilge is dry.

Does the boat only lean when on plane and does it get worse with more speed?

Does the boat have power steering?

If it is only when on plane then check the boat bottom. if it looks good you might want to look at the trim tab behind the prop on the cavitation plate.
This is to correct for different type of props to make the steering even and stop it from pulling to one side. Most have marks on them to help you line it up. Note the position it is in then adjust all the way one way and try a run to see if it is the same, better, or worse. If it gets worse then try the other way.

The outdrive trim tab is to adjust to where the wheel turns with equal pressure in each way at your favorite speed. If your boat has power steering then you may not notice it turning harder to one side or the other and if the trim tab is off it can make the boat lean to one side or the other.

One last question. When you did your test ride and it was leaning was it windy with wind blowing from one side?
Both my boats will lean into the wind when I have strong cross winds. This is normal and can be corrected with adjustable boat trim tabs.

Bodega Bay Weather On May 14 2008 Improving at 10 PM
Winds North at 350 degrees true at 9.7 knots, gust to 11.7 knots. Water temperature 47.1 degrees F.
Swells 7.2 foot every 10 seconds Chop at 6.8 seconds Wave steepness = average.

 

[Danny in CO]

Re: Trim Tabs???

"Does it lean when stopped in the water?" No, it sits level when stopped and bilge is dry.

"Does the boat only lean when on plane and does it get worse with more speed?" Yes, it gets worse with more speed.

"Does the boat have power steering?" Yes.

"If it is only when on plane then check the boat bottom. if it looks good you might want to look at the trim tab behind the prop on the cavitation plate." The boat bottom is clean and smooth. I'll look at the trim tab behind the prop.

"One last question. When you did your test ride and it was leaning was it windy with wind blowing from one side?" No, it was not windy.

Thanks for your inputs. I'll check the trim tab and try different settings.
Danny

 

[Boatin Bob]

Re: Trim Tabs???

I would also try trimming up the drive some once on plane to see if that makes any difference.

 

[LubeDude]

Re: Trim Tabs???

It is a natural accurance with most all boats to list to port because of the torque of the engine. More pronounced with more power. Trimming the engine up after on plane should all but eliminate the problem.

 

[Jdeagro]

Re: Trim Tabs???

If you have a hydrofoil on the O/D remove it.

 

[Danny in CO]

Re: Trim Tabs???

If you have a hydrofoil on the O/D remove it.

Jdeagro,

I've never had a motor with a hydrofoil. I think it is the "whale tail" looking thing above the prop, right? Why would it cause the boat to list to the left? I'm a big guy (230 lbs) and it seems like the drivers side should ride lower. I'm thinking the torque of the motor is causing it, right?

Thanks,
Danny