Mercury 25hp wont select reverse.

[mark1961]

I have question for the knowledgable folk here......my friend has a 2002 model 25ML Mercury motor, last time out he went to select reverse with no luck and ever since the situation has been the same, no reverse, selects forward gear fine. This motor has the two shift cables coming from the tiller arm pivot. They both appear to be in good condition and working but the reverse side comes to stop before selecting reverse. The tilt lock was activated, so it should be going in reverse, tried all the obvious stuff too like rotating the prop with no joy. Any ideas what could be causing his problem?

Thanks in advance for any help you can give.

 

[orbanp]

Re: Mercury 25hp wont select reverse.

Hi Mark,

I take you have the electronic copy of the service manual, there was a pointer to it here on iBoats. If not, you should get it! May be someone else can chime in with the link.

There are linkages between the first cam gear (activated by those cables) and the shift mechanism and throttle mechanism. Those linkages can be adjusted (the length of it). You could start by checking if that adjustment is correct. For the shift linkage the manual asks to set the shift link rod to a length of 5-1/2 in. (13.9 cm) as measured between ball joint centerlines.

Good luck, Peter

 

[mark1961]

Re: Mercury 25hp wont select reverse.

Thanks for chiming in Pete, is the linkage you refer to the one with the plastic ball joints which connects between the upper geared wheel and the throttle cam?

 

[quicktach]

Re: Mercury 25hp wont select reverse.

Check behind the carb too. The linkage goes horizontally to the starboard side there it connects to a vertical rod that goes to the lower unit. Make sure everything fits ok and isn't loose or out of adjustment there or binding. Could just be that 5 1/2 inch adjustment too!

 

[orbanp]

Re: Mercury 25hp wont select reverse.

Thanks for chiming in Pete, is the linkage you refer to the one with the plastic ball joints which connects between the upper geared wheel and the throttle cam?

The rod with the two plastic ball joints activates the throttle. That is on the primary gear (actuated by the cables).
You want to check the other rod, it connects the secondary gear to the lever on that horizontal shift shaft.
And yes, check if the rest of the mechanism works freely, as suggested by "quicktach".

Peter

 

[mark1961]

Re: Mercury 25hp wont select reverse.

Ok copy that.....the horizontal shaft looked fine when i was over there, all appeared free......will check out the other linkage as suggested.

Cheers and thanks again both of you.