1970 Merc 135HP No Forward or Reverse

nelligcm

Cadet
Joined
Aug 8, 2005
Messages
6
I have a 1970 135HP Merc Outboard. It seems as though the lower unit does not fully engage in both Forward or Reverse. I can get it to click in at very slow speeds but once I increase the throttle, even slightly, it seems to slip out of gear. Very similar description to a posting below but I do not figure it to be the prop. Also I pulled the lower unit off and everything seems to be working as it should. Need a little help here.
Thanks
 

jze1212

Petty Officer 2nd Class
Joined
Feb 11, 2006
Messages
156
Re: 1970 Merc 135HP No Forward or Reverse

Have you checked your linkage? Sounds like it is not engaging fully either way, Check the linkage on the motor end, be sure that the gromets that are holding the cables are not compromised..
 

nelligcm

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Joined
Aug 8, 2005
Messages
6
Re: 1970 Merc 135HP No Forward or Reverse

Linkage is working fine. Almost seems the rotation of the shifting rod is maxed out before the lower unit can get into gear.
 

jze1212

Petty Officer 2nd Class
Joined
Feb 11, 2006
Messages
156
Re: 1970 Merc 135HP No Forward or Reverse

Perhaps there is some sort of cam lobe in there that is worn out? OR, have you cracked open your control box? It's possible that someting is out in there..

Could be something in the lower unit though.... worst case scenerio
 

nelligcm

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Aug 8, 2005
Messages
6
Re: 1970 Merc 135HP No Forward or Reverse

Control box is operating correctly. The cam has been suspect of the hole problem. Would the cam be at fault if it only slips out under a load? Or would it be worn gears? Not much chavings coming out when I drain the lower unit oil. There's some, but the thing is 36 years old. Not enough shavings ( I don't beleive) to be of concerne.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1970 Merc 135HP No Forward or Reverse

what i'm going to tell you is not necessarily easy and can be dangeous. ( ihave 71 1350) remove the cables from the engine, reattach the throttle only. using a long screw driver you can move the shift slide all the way to the rear this is forward. give it a test run, if it comes out then there is a problem, the move the slide all the way forward and this is reverves, give it a try. if it stays in gear replace the cables, or complete controler.. just replace the internal and external wiring harnesses, new controler and cable on mine, did Clams linc N sinc, it's like a new engine. now the impeller is out. it was on the list to do.
 
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