Merc 470/170 dies in reverse

[Hic58]

I just purchased a Merc470/170HP. Motor starts and runs great. Shifts into forward normally. When shifting into reverse, the lower unit goes into gear and prop turns. As the shift lever is further advanced the engine dies. I noticed that there is no indication that the throtle linkage moves. Throtle linkage seems to work fine in neutral in reverse or forward. I had my son manually advance the throtle as I increased advanced the shift lever in reverse and the engine did not stall. I think my linkage is misadjusted. I am guessing that initially the lower unit goes into reverse gear and further advance of the shift lever engages the clutch without increasing the throtle and the engine shuts down. I am not a mechanic and have arrived at this by reading my Clymer's manual. Please give me some guidance.

 

[180shabah]

Re: Merc 470/170 dies in reverse

Not sure about this particular drive, but all newer mercs have a shift interupt switch that kills power to the ignition during a shift to lessen wear on drive components( and the audible gear gnash) if the linkage is misadjusted or binding it can hold this switch in the open position, thus stalling.<br /><br />Good Luck

 

[Don S]

Re: Merc 470/170 dies in reverse

Sounds like you have the cable adjusted to far into reverse causing it to activate the shift interrupt system when it shouldn't be.<br />Below is a link to section 2 of the Mercruiser service manual, it will give you detailed information on how to readjust the cable.<br /><br /> http://www.boatfix.com/merc/Servmanl/6/6A2R3.PDF <br /><br />Also, here is a link to the complete manual for your drive.<br />The links aren't obvious, so just scroll your cursor over the page to find the links.<br /><br /> http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf <br /><br />Forget the Clymers, not worth the paper it was written on.

 

[gmcjohnny]

Re: Merc 470/170 dies in reverse

sounds like its time for a shift cable from motor to drive

 

[achris]

Re: Merc 470/170 dies in reverse

The thing that I have found a few times with 'dies in reverse' is that the upper shift shaft seal is leaking and water and crud is getting in to the shift slider cavity. As the slider tries to move further back (as reverse is selected) it stops against the packed up crud, then pushes the shift cutout switch. <br /><br />Remove the leg, clean out the slider cavity (in the leg), replace the shift shaft seal, disassemble the cable and clean it out, reassemble it all then enjoy some boating. <br /><br />Chris.................

 

[Hic58]

Re: Merc 470/170 dies in reverse

You guys were right on target. I needed to make a slight adjustment to the micro switch (kill switch) and she is shifting fine now. I also hit it with some "Corrosion Block" which seems to correct a multitude of areas. I particularly appreciate the website on how to adjust the switch. My manual did leave a lot to desire in this area. Thanks again and happy boating.