Merc 60hp dropping a cylinder...

[saumon]

(please excuse my english, i'm french speaking...)<br /><br />I was on the lake today with my 1993 Merc. 60 hp 3 cyl. (S/N 0D074327) and, suddenly, it loss power at WOT, dropping to around 3000 rpm and hardly idle without dying. I check the plugs and the one from the top cylinder was soothy black (the two others looks fine: light gray). I then start the engine and disconnect the no.1 wire, without change...so there's no spark here.<br /><br />I had to came back so i run it (very rough) on 2 cylinder and, magically, after approx 20 min., it kicks in and everything went normal.<br /><br />A couple of questions for you guys: <br />1- could it be something else than a bad coil or switchbox?<br />2- how could i know as it now run fine?<br />3- is it normal for those critters to fail then goes on?<br /><br />Thanks for your help.

 

[Laddies]

Re: Merc 60hp dropping a cylinder...

First ck compression or at lest a spark gap to know that it is lack of spark. Could be a bad coil, switch coils to see if that don't get spark on that cyl. if you don't you have a bad switch box. Those engines are troubled with ign. problems

 

[saumon]

Re: Merc 60hp dropping a cylinder...

Thanks Laddies, but as i said: how could i do these troubleshooting procedures as the engine now run fine? I dont want it to dies 10 miles from shore but now it is ok, so swapping coils won't help me.

 

[Laddies]

Re: Merc 60hp dropping a cylinder...

Just swap the coils or coil input wires to test the unit not to try to fix it. If the lack of spark go with the coil it's the coil, if it stays in the same place it's the switch box

 

[saumon]

Re: Merc 60hp dropping a cylinder...

Thanks again Laddies, i fully understand this procedure! <br /><br />What i'm saying is that, now, this problem (no spark) no longer exist. Is there's something i could now check or do i have to wait that it happened again?

 

[Laddies]

Re: Merc 60hp dropping a cylinder...

It is almost impossible to find a problem with a system when it's not acting up, even with the best test equipment. I would say that I am 80% sure it was the switch box if a stator winding or coil winding quits they usally are gone for go but if a switch box has a switch stick inside it they will give intermittent problems

 

[saumon]

Re: Merc 60hp dropping a cylinder...

Thanks, <br /><br />on Mercury Parts Express with my S/N, it give me part #19052A 8 for the switchbox at a modest 414.41$CDN (around 400$US)...ouch!<br /><br />Have also seen a Sierra #18-5791 at 209.41$US + S&H and a RAPAIR/CDI #114-9052 at 290$US.<br /><br />i think i'll begin to look on e-bay for a switchbox...can you please give me some hints (other sources, best deals, reliability)?

 

[Laddies]

Re: Merc 60hp dropping a cylinder...

If you buy new Rapair has by far the best part

 

[muskyscratcher]

Re: Merc 60hp dropping a cylinder...

I have the exact same problems with a '95 60 hp.<br /> Why do 'they' sell motors with known ignition<br />problems, that have to be fixed every three years, I'll never buy Merc again.<br /> I'd also like to know why my '97 9.9 Mariner 4-stroke was made buy Yamaha and has oil pressure<br />problem, but can't seem to get a response here.<br />Search Merc/Mariner 9.9 4 stroke and see how many response/answers are there. I think everyone's out on the water.<br /> Bought both motors brand new and less than<br />ten years later neither one is worth @#$**.<br /> Just lucky I guess. Both motors run fine, I just<br />can't go over 2000 RPM..It's wonderful<br />Never had a problem with my Johnson.<br />(intentional pun)<br /><br /><br />