Poor handling, hard to steer at full speed

[ShoestringMariner]

Hey everyone, I just did a test run on a new to me boat. It’s a 1976 StarCraft 16’ superport.

at speed, the steering is extremely difficult to turn. Fine at low speed’s but very very difficult at top speed.

The motor is a 1976 mercury 650. There seems to be a fair bit of play in the steering system. The wheel has a little bit of side to side before the motor will move. Third also it appears to be some slop in the motor mount bushings etc. I can wiggle the motor around before the steering seems to react.

The boat also seemed to list towards drivers side while going straight. I’m only about 210 pounds and I was the only one in the boat during the test. The weather was windy and there was a fair bit of chop. The wind was hitting my side door so it’s seem to be counterintuitive to the direction of list that makes any sense. I would’ve thought that wind would’ve pushed it over the other way ( it was listing in the direction of wind)

minimal water in the bilge
Gas and batteries were balanced side to side

 

[Lightwin 3]

What is the position of the trim tab just above the prop?

 

[ajgraz]

Also, how deep is the lower unit? If too deep it can steer funny or want to list. Need side view pics of lower unit in respect to Hull bottom.

I had a 79 70hp merc 3 cylinder, very similar motor I believe. My mount bushings we’re toast too, I recall I somehow taped them up and poured 2-part polyurethane in them and they were good as new. (This was years ago, don’t recall exactly the procedure)

 

[ShoestringMariner]

What is the position of the trim tab just above the prop?

in line with water flow. Like an upside down shark fin. I will post a photo of it.

 

[ShoestringMariner]

Also, how deep is the lower unit? If too deep it can steer funny or want to list. Need side view pics of lower unit in respect to Hull bottom.

I had a 79 70hp merc 3 cylinder, very similar motor I believe. My mount bushings we’re toast too, I recall I somehow taped them up and poured 2-part polyurethane in them and they were good as new. (This was years ago, don’t recall exactly the procedure)

Well that is pretty darn cool. I’ll have to look into that. See the photo. The flat plate above the prop is roughly in line with the keel. It’s a bit of a V bottom here.

 

[ShoestringMariner]

That one was too dark, let’s try another

 

[GA_Boater]

Turn some lights on, Shoestring. Pic is too dark to see anything.

On most motors the trim tab is turned so the rear is a little to the right to counteract prop torque.

 

[ShoestringMariner]

Turn some lights on, Shoestring. Pic is too dark to see anything.

On most motors the trim tab is turned so the rear is a little to the right to counteract prop torque.

Thank you. I posted a second photo. Stormy day here. I will have to adjust it to the right. I have it dead in line with direction or in line with the housing

I also lost some sort of collar flange thing off the prop during the test run. Not sure what it was or how it was attached. I just noticed it was missing when I got back in

 

[ajgraz]

That’s a heckuva deep v, that would contribute to some wander. Motor looks low, I’d want to raise it a few inches.

collar flange? Locking tab maybe?

 

[ShoestringMariner]

That’s a heckuva deep v, that would contribute to some wander. Motor looks low, I’d want to raise it a few inches.

collar flange? Locking tab maybe?

Here is the before photo. The collar (?) is a little bit banged up. I did not realize it was a collar at first as the previous owner dusted this whole thing with a spray can to clean it up. If you look at one of the earlier photos I posted, you’ll see a three eights of an inch ledge that’s not painted. It’s like it was a piece of 3 inch or 3 1/2 inch diameter tube stuck on. no fasteners. Just like a bit of a flange, that is now missing. Assuming it has something to do with extending of the exhaust port? Only thing I can think of

 

[Fed]

The wind was hitting my side door so it’s seem to be counterintuitive to the direction of list that makes any sense. I would’ve thought that wind would’ve pushed it over the other way ( it was listing in the direction of wind)

Completely normal, it happens because the wind is trying to blow you off course towards Port & you are steering towards Starboard to counteract it and maintain your heading.

Disconnect the steering at the tiller and see if you can move the motor from side to side with one finger, if not start greasing the swivel bracket nipple. (Should be a single nipple about 1/3rd of the way down from the top on the Starboard side). Grease it & work it by hand until grease is coming out of the top & it's a one finger job to move it.

Take a clear picture of the leg in relation to the hull when parallel to the hull, it may be a low.

 

[ShoestringMariner]

Completely normal, it happens because the wind is trying to blow you off course towards Port & you are steering towards Starboard to counteract it and maintain your heading.

Disconnect the steering at the tiller and see if you can move the motor from side to side with one finger, if not start greasing the swivel bracket nipple. (Should be a single nipple about 1/3rd of the way down from the top on the Starboard side). Grease it & work it by hand until grease is coming out of the top & it's a one finger job to move it.

Take a clear picture of the leg in relation to the hull when parallel to the hull, it may be a low.

Thanks, I took your advice and disconnected the steering. The motor turns easily with one finger and the steering with motor both connected and disconnected works smoothly and easily. The slop in the steering appears to be caused by play between rack and pinion gear. ( a bit of stab and steer if you will) I greased what I could.
I also adjusted the the trim tab as someone suggested.

I‘m puzzled however. None of this makes much sense as to why the steering was nonexistent at full throttle. I mean it was immovable or close to it. Flat out, but not at low/half throttle. Sort of makes me wonder if there’s binding in the bushings under heavy load.

Theres also fair bit of sloppy play when the neutral/reverse lock is in place. Like it’s worn out. At least 1/2” of “clanky” movement fore and aft. Is that normal? The lock pawls don’t look worn but I’m also a newb
Testing it it again tomorrow. Anything specific I should be looking for?

 

[ShoestringMariner]

Another pic below- pic would not load

 

[ShoestringMariner]

[No message]

 

[ShoestringMariner]

EDIT: motor is sitting straight upright from gearcase oil change. Normal trim position is right up tight against the transom

 

[Fed]

As a test remove the fin but keep 2 hands on the wheel and be prepared for any unexpected behavior.

Mark the fin position at home then remove it in case it's hard to undo.
Allen key or 1/2" AF from above, I can't recall which.

Keep in mind the whole time the fin is not a rudder for the boat, it's a trim foil for the outboard motor.

FWIW I think there were 2 different sized fins (trim tabs) for that motor.

Just noticed you have already moved the trim tab so marking it doesn't mean much now, still need to go about the exercise in a methodical manner.

 

[Fed]

Saw your edit and the pics sorry I can't help with the reverse lock but the motor looks like it would benefit by tilting out one hole, hard to tell from pics though.

 

[ShoestringMariner]

Saw your edit and the pics sorry I can't help with the reverse lock but the motor looks like it would benefit by tilting out one hole, hard to tell from pics though.

Thanks, I will try that. You are right, trim needs to be reset. I changed it to do a gear oil change

 

[ShoestringMariner]

Thanks everyone. I readjusted the sacrificial anode or trim tab, and took it out for another run tonight. I greased the Teleflex rod at the outboard And steetong seem to be reasonable at high-speed’s tonight. That being said it was fairly calm and the water was flat. Very little wind. So far I’m pleased.
Thanks again guys

 

[dingbat]

EDIT: motor is sitting straight upright from gearcase oil change. Normal trim position is right up tight against the transom

If your “normal” trim is up tight to the hull as shown in earlier pictures you’ve found your problem....

The motor should be perpendicular, if not slightly outward from vertical, on plane. Properly trimmed, there should be little to no pull at all on the helm. I can let go of the helm and walk away when trimmed out