Tiller Handle Adjustments For accurate “shift/stop” positions

[JohnRude]

I have now completed repairs and restorations on about 15 OMC motors. In all but two, the tiller handle marks never match what the motor is supposed to be doing. What is the secret to putting the tiller handle back together and matching the gears up so that “shift”, “slow,” “start” and “fast” are in the correction position?

[aquasonic]

It doesn’t seem like there is an easy fix for that problem. Maybe swapping out the main gears in the tiller?

[frankr]

Never was a way and probably never will be. Just think of it as”Fast” is this way and “Slow” is that way and it will be right on.

[Steve D]

When shifting you’re usually just listening anyways, for the rpm’s to be low enough to shift, not looking at the indicator.

[fleetwin]

There is no way of “reindexing” the throttle handle gears due to the one large lug.  I fear that if you tried to “reindex” the smaller gears by the vertical throttle rod you would run the risk of the gears jamming or perhaps one gear releasing from the other rendering the throttle useless.  Trying to favor the lower throttle setting by reindexing the little gears might prevent the throttle from reaching wide open as well.

I guess I would look for some older throttle indicator rings to see if perhaps they are labeled differently.  But, in the end, we are never looking at the throttle handle indicator while the engine is running anyway.  The only exception might by turning the grip to “start” before starting the engine cold.

[JohnRude]

It can’t be this complicated. And yes, I usually listen to the revs. But from the factory, the settings were correct. I have two almost new, never been tampered with OMC motors. The tiller ranges from Stop, through every position to fast…smoothly. The gears didn’t change over the years, only people taking the tiller off and putting it back together incorrectly. I’m not talking antique motors here. Just your boring old 5.5 to 18 hp OMC motors.

We seem to be pretty precise about colours, spark, timing, gears, and so on in our endevours to keep these motors running and looking their best. I’m surprised to hear, “oh well, it’s a minor thing. Who cares if the tiller handle is screwed up?” I’ll post again when I figure it out.

[aquasonic]

The two shaft gears did change sometime in 1956 from stamped gears to cast gears, but I’m not sure about the actual gearing itself. From what I’ve read the two types of gears are not compatible but haven’t tried it.

As far as reassembly goes, the two shaft gears at the tiller “elbow” only fit together only one way due to the large lug on one and the receiving gap on the other as fleetwin pointed out.

The remaining two options are the tiller grip assembly and the two gears that mesh at the vertical control arm. The two that mesh at the control arm can be visually inspected to see if there is misalignment.

Lastly is the tiller grip assembly. The shaft gear end fits into the friction block inside of the grip. If the “D” shaped keyed hole in the friction block is distorted, that could affect the orientation of the entire assembly.

At the end of the day, if you solve it, I’d like to hear about it.

[Steve D]

I think it just might be wear and tear on the parts making up the throttle advance. The parts involved with the throttle advance were never made with the tolerance and precision of say, lower unit gears. Plus, there’s play involved all the way through.

While turning the throttle handle if you look closely, there are at least 4 or 5 points where there is play…the first set of gears under the handle (it doesn’t matter if they’re stamped or cast, but the earlier stamped ones seemed worse with more play), then there’s play at the pinion gear and throttle gear, then the pin in the vertical throttle lever moves some, and finally the upper part of the throttle lever itself can move where it’s secured in the bearing clamps.

All those little, consecutive incidents of play in that progression add up to being able to turn the throttle handle a bit before it has any effect on advancing the link and stop arm attached to armature plate. And that translates to inaccuracy in the tightly grouped readings on the indicator.

That’s just my humble opinion.

1 user thanked author for this post.

aquasonic

[fleetwin]

JohnRude wrote:

It can’t be this complicated. And yes, I usually listen to the revs. But from the factory, the settings were correct. I have two almost new, never been tampered with OMC motors. The tiller ranges from Stop, through every position to fast…smoothly. The gears didn’t change over the years, only people taking the tiller off and putting it back together incorrectly. I’m not talking antique motors here. Just your boring old 5.5 to 18 hp OMC motors.

We seem to be pretty precise about colours, spark, timing, gears, and so on in our endevours to keep these motors running and looking their best. I’m surprised to hear, “oh well, it’s a minor thing. Who cares if the tiller handle is screwed up?” I’ll post again when I figure it out.

It does seem like the indicators on the older engines (50-60s) are more accurate than newer models.

[Sputter]

I’m a newbie and not sure if this is relevant, but the throttle “position indicator” ring on my 1958 Johnson 5.5 Hp has a gap underneath with quite a bit of play.

I don’t know if it’s supposed to be glued in place, but it moves when I turn the grip. Is this the kind of thing you’re trying to correct?

1956 Johnson 15 Hp, FD-10
1958 Johnson 5.5 Hp, CD-15

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