25 hp Merc....pulls to the right!!

[Mnfisher]

I have a 25 hp mercury, tiller on an older 14' Starcraft, deep hull boat. I had a water pump installed last fall and the engine was "revving" up when planeing. They did some adjusting but can't remember exactly what they did. I didn't get it out but when I had it out yesterday, it pulled very strongly to the right and I had to compensate greatly with the steering to keep it straight. I'm assuming something needs to be re-adjusted. Any ideas would be appreciated. Should I expect a "no charge" adjustment from the shop? Thanks for any ideas.

[TruthWalleyes]

Take a look at your motor, is it in the center of your boat?

Also, If your motor is on straight, there is a small tab directly above the prop to compensate for the prop rotation. That may require slight adjustment. See pic below.

Also, if the boat is weighted more on one side of the boat than the other, it will cause the boat to turn.

[EBass]

Yup that's the ticket. May need to adjust it and try it out then adjust it again. That's what I had to do. Sometimes the bolt will loosen. I found that out too.

[Mnfisher]

Motor is on straight but the tab was leaning noticeable to the right so I moved it to the left but not completely centered. I'll try that and see what happens. Will that affect the "plane" any? I'm assuming the tab should be more to the left and not more to the right. Thanks guys!

[CAMAN]

Actually from what you describe with the "hard pull" the trim tab probably won't do much to help the problem. On my old 25hp Mercury I had the exact same issue and found it to be the mounting pads on the lower-mount were worn out and misaligned. (#20 and #21 in diagram)

Yours may be installed incorrectly or worn out. Or the bolts holding the assembly together came loose.

[Mnfisher]

Camen: So....to fix the initial problem of inadequate planing, would the mechanic have been working in the area you are describing? If so, then it does make sense that maybe something may have been installed wrong or overlooked.

[TruthWalleyes]

Thats possible if he had to pull the entire lower unit off.

[fsnrod]

I think you have move the trim tab to the right you have to move the way it's pulling

[RIPN LIPS]

The trim tab I would say is not the problem. Trim tabs do very little and obsorb the static electricity from the prop and ground it to the boat. With out that the paint would start to fall off the lower unit. Motor mounts sound like they are shot or installed wrong.

[Mnfisher]

Thanks guys for all the good advice. If I end up taking the boat/motor back in, I'll have some "suggestions" for the mechanic! I'll try the trim tab first though. Probably take it out again Thursday. I did read in a book about an eninrude about the trim tab needing adjusting if it pulls to hard one way. Anyone know of a reputable/good motor mechanic around the Cambridge area, any direction? Just wondering if I should try a different mechanic. Thanks

[fsnrod]

That trim tab makes a big difference on the motor pulling one way or the other.

[Mnfisher]

I moved it to the left today and it was worse, so put it back to the right again. It was much better but still wasn't quite right. It was windy too so hard to tell but I'll see if I can move it farther right. Thanks.

[boatfixer]

After you are certain the motor is on straight, think of you propeller as a paddle wheel. As it rotates clockwise, it wants to pull itself in that direction. The trim tab is there to counter that torque. Rotating it so that trailing edge of the tab goes in the direction of the pull counters the torque, acting like a rudder.

Also, if the mechanic removed the lower motor mounts to remove the lower unit, find another mechanic

[Mnfisher]

Thanks Boar. I appreciate any and all suggestions. Jim

[Mnfisher]

After 3 or 4 adjustments to the trim tab and moving the motor over to the left about an inch, the problem is still there. I can only guess that it must be the mounting pads (Caman suggested ) or motor mounts (RIPN Lips) (ARe the mounting pads and motor mounts the same thing? I think I'll take it in somewhere but am reluctant to take it back to where I originally had it fixed. I did stop in there a couple of weeks ago and the mechanic and clerk treated me well but the owner was rude and short with me. Anyone have any suggestions in the north metro from Blaine to Mora, Princeton or Hinckley. You can send me a PM if you'd rather not endorse one publicly. Thanks much. Jim

[amateurfishing]

PM sent