Only firing on 3 cyl

[Smittjoe]

Having problems getting my 71 merc running
its a 165 inline 6 thats only firing on 3 cyl

 

[Bondo]

Ayuh,...... Welcome Aboard,...... I'm Guessin' this is an Outboard motor,..??

I'll move this to the Merc Outboard forum for ya,.....

 

[merc850]

Having problems getting my 71 merc running
its a 165 inline 6 thats only firing on 3 cyl
If that's a distributor model the only reason that it won't fire 3 cyls. are plugs and wires or a damaged cap/rotor. From the confusing wording I'm guessing it's a 1965 dual point/coil system; the next dual system is a Tbolt ADI which came later than 1971. Post the serial Nr. or pictures.

 

[racerone]

Sounds like a 165 HP MERCRUISER to me or the HP is not 165 !!!!

 

[jimmbo]

deleted

 

[GA_Boater]

Having problems getting my 71 merc running
its a 165 inline 6 thats only firing on 3 cyl

Welcome aboard, Joe.

Before we move this around anymore - Is this an outboard or a Mercruiser? Part of your problem description points to outboard and part points to Mercruiser.

 

[merc850]

If it is a Mercruiser it still uses point ignition so my earlier post is partly accurate; but there could be valve issues or a gasket problem. I worked on one that ran fine until it warmed up then a crack in the head opened up and doused 2 cyls. Owner did his own "winterizing".

 

[Smittjoe]

Its a sterndrive 165 hp inline 6 merc
1971

 

[merc850]

I think it's a chevy 6 so you use automobile troubleshooting methods; compression, valves, timing, sticking lifters, intake gasket(s) leaking etc.