Yamaha Outboard Stuck in Reverse !

[markpj23]

We must have been quite a funny sight - trying to go backwards in a RIB dink in strong winds..... We'd get about 20 yards then the wind would blow us around so we'd do a 360 deg turn, .... repeat until we were close enough to shore to paddle in. So if you saw those 2 fools doing donuts through the Ft Jefferson anchorage this past weekend - now you know the rest of the story.

Even though it's fun to go backwards.... I wonder where I need to start looking at repairing my Yamaha 15HP 4-stroke (Model F15esh). I can see that the linkage is operating as it should. That makes me think that the lower unit has to come off ....

Any suggestions?

[DaveC]

Maybe you can mount it on the bow to go forwards?

Sorry, couldn't resist. I hope you get it squared away...

[FSMike]

Does the linkage actually move? If that's the case somewhere down the engineering chain something is not moving and you will have to access it. Try manually moving the propellor back and forth. There's a chance that will get it working, at least on a temporary basis.

[GordMay]

Pulling the gearshift lever towards you puts the engine in forward gear so that the boat moves ahead. Pulling the gearshift lever backwards puts the engine in reverse.
Shifting may only be done at low speed and on idle RPM.

See ➥ Yamaha Outboard Parts 2006 and Later 4-stroke F15ESH 66MK-1000001 CONTROL Diagram

[sabray]

trying to remember how mine was set up.
I recall removing one of the water proof plugs just below the head end. Inside that is a clamp or connector that attaches the upper control rod to the lower end control. Probably loosened up hopefully because thats an easy fix. thats how i remember it.

[Captain Bill]

The shift mechanism in the lower unit is quite simple and difficult to jam. What is more common is for the nuts that hold the upper and lower shift rods together come loose or get stripped. The rods push down in reverse so even a stripped nut will push it into position, but cannot pull it into neutral or forward. Some outboards have a small screw on panel just above the lower unit to allow the nuts to be unscrewed and the rods separated so the lower unit can be removed. Others require the lower unit be dropped a inch or so before the nut can be accessed. My guess is that the problem is in the upper shift mechanism or the rod connection rather than the lower unit. The connection nuts are parts 10 and 11 in Gord's diagram. I would make sure that the upper end of the shift rod (9) is in place and moves up and down when the shift lever is moved from forward to reverse. If it moves properly then check the rod connection nuts. If it doesn't go up and down then the problem is something loose in the upper mechanism.

[markpj23]

You guys are great - as usual! I hope the design in 1999 was similar. I will check this out tomorrow.
Many thanks!

[markpj23]

Just my luck - this model has no access plate along the shaft. I'll have to drop the lower unit.

[osirissail]

If you can see the long thin shift rod (#9 in GordMay's diagram) move up and down in response to the shift lever- then most likely you have a problem down inside the lower unit.
I had a motor that would not shift out of forward. After taking off the lower unit I noticed that the shift rod had a plastic wedge on the end that forced two opposing camplates apart. As you shifted from forward to neutral the cam plates separated enough to disengage the drive shaft from the lower unit gear. Shifting to reverse caused the cam plates to separate wide enough to engage the drive shaft with the reverse gear. The adjustment of the plastic wedge was critical to allow the gears to meet. Damage to the plastic wedge or its attachment to the shift rod would cause the drive shaft to stay engaged in the nominal fwd or reverse gear.
- - You are going to have to remove the lower unit. But when you do it - look carefully at how the exhaust systems connects with the lower unit passes to the exhaut through the propeller. There are gaskets or rubber spacers that must me carefully aligned during re-assembly. Looking carefully at how the parts align during dis-assembly makes it easier when trying to put everything back together again.
- - Also the water pump for the cooling water is sometimes down there at the junction between the lower unit and the main body. Again seals and how the pipes align should be carefully noted during dis-assembly so you can remember how to put it back together again.

[sabray]

Originally Posted by markpj23

Just my luck - this model has no access plate along the shaft. I'll have to drop the lower unit.

Haven't seen that before but I've only owned 4 outboards. All 3 had a point to disconnect the shift rod do the lower unit could be removed. My yamagata has a rubber plug that one prys out. Some where that rod has a junctionsnd access point.

[markpj23]

Thanks guys!