Mariner 3Cyl 70 LU - Reverse not engaging

Daibheid

Seaman Apprentice
Joined
Jun 17, 2004
Messages
48
Hi, First let me say this is my first post after 'lurking' here for a while. This is an astonishing resource of accumulated knowledge and I'm hoping one of you experts can help me out.<br /><br />The 'new' engine starts fine and engages foward after a little 'clacking' - seems normal but I imagine slightly slower than I've been used to on other OBs. However, engaging reverse it just clacks and will not engage. I've adjusted the remote cable to ensure it's pushing all the way to the back of the slot in the powerhead housing. No difference. I've read all the previous postings on shift and LU problems and learned a lot already. One thing the posts indicate is that reverse shifting may have been fouled up last time this engine got an impeller but the guy I just bought it from said everything worked fine (they all say that I suppose!).<br /><br />I've ordered a new impeller anyway and had hoped to fit it before a real outing but parts take a long time to get over here in Ireland and really want to have the maiden voyage this weekend. I don't want to drop the LU to check the shift shaft without the impeller to replace.<br /><br />My 9 year old daughter has already gone out and bought her own life jacket and fishing rod with her allowance ahead of the weekend so I really want to give it a try. I would appreciate any advice, eg can I go ahead and use it with just F and N for now or do I risk damaging anything.<br /><br />The local Mariner dealer who couldn't look at it for weeks (and might be uaffordable for my old engine as he quoted $130 to fit a new impeller) says it sounds like the clutch will probbaly engage OK in reverse eventually. He saw no problem with using as is for now. He also said he thought the shift shaft had a master spline, ie couldn't upset the gear selection by being out a spline.<br /><br />Engine S/N is 6074129, which I believe makes it a model 7070620 from 'about '81,2,or3. I don't have much history on it but it's supposed to be low hours and laid up for the last 3 years. Used in the sea but flushed afterward.<br /><br />Apart from the cable adjustment I can see little else to affect reverse selection unless the reverse gear is worn. IMHO, it's usually the higher mileage foward gear that starts to expire from wear first. Also the clacking noise is like the usual low frequency clutch noise rather than gears grinding.<br /><br />The only other info I can add is that in F the prop locks solid in gear turning by hand while in reverse it kinda ratchets.<br /><br />Thanks in advance and sorry if this is long but I really don't want to let my daughter down this weekend plus my wife is giving me grief about being suckered!<br /><br />Daibheid (Irish for Dave)
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: Mariner 3Cyl 70 LU - Reverse not engaging

welcome aboard,<br />dis-connect shift cable and shift manually.<br />if this solves problem, install new shift cable.<br />if it doesn't, the clutch dog may be worn and need<br />replacing. cheap little part, but entire L/U needs<br />to be "pulled" apart to install it.<br />a worn control box gear can also cause this.<br />good luck,<br />M.Y.
 

Daibheid

Seaman Apprentice
Joined
Jun 17, 2004
Messages
48
Re: Mariner 3Cyl 70 LU - Reverse not engaging

Thanks MY for your advice. I checked and adjusted the cable to ensure it pushed the shift mechanism right to the back of the track. I don't have a manual yet but can't see any further adjustment between the cable end and the LU?<br /><br />Kinda looks it may be the clutch dog.<br /><br />However I'm curious about 2 things, would Foward not be more likley to wear out first and I'd have expected that Foward gear should have the same problem or is there a separate set of dogs for foward?<br /><br />Either way at least I feel happier I may get this sorted without huge expense and that I won't do any harm giving it a run. I can go to bed now!<br /><br />Regards and thanks,<br />Dave
 
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