#3 & #5 Cylinder (No Spark) Tower of Power

Aight... I have been working very hard to get my grandfathers boat back in working condition. I have a 1985 90cyl tower of power, which has very few hours on it believe it or not. About a month ago i was out on the lake when all the sudden I couldn't get it to accelerate over 2800 rmp and it wouldn't want to idle. So I just thought it needed a carb rebuild etc. So needless to say it now has rebuild carbs, fuel pump, fuel lines etc. Compression also check out too.

So while completing everything and doing a routine spark test I noticed that the #3 & #5 cylinders aren't getting spark. With the little electrical knowledge that I have and some research online it seems to me that the switch box which controls the odd cylinders has gone bad.

The stator i don't believe is the culprit because it clearly has been recently replaced since the wires coming off the stator are much newer that the wires that originally came from the factory. Also, since I'm getting spark in the #1 cylinder it just does not make sense that the problem would be the stator. Which, like I said makes me think the problem is the switch box.

Anyways I'm just trying to get some information from people who know more than I do about this kind of stuff. Any information for trouble shooting or ruling out possible culprits would be much appreciated.

Thanks
http://www.maxrules.com/oldmercs/Wiring/1966ona/37.jpg (Ignition Wiring)

Re: #3 & #5 Cylinder (No Spark) Tower of Power

Hi, Fishin, I had a similar problem with my 1988 115. I suggest you swap the switch boxes to see if the problem follows the box. if it does not, you will want to check you flywheel magnets and the stator assembly. mine was a bad switch box. Good luck!!!!

Re: #3 & #5 Cylinder (No Spark) Tower of Power

SS47, the more I here about people having this problem it almost always seems to be the switch boxes on there old towers.Anyways, can I not just swap the red/red-white wires and the blue/blue-white wires coming from the stator to the switch boxes to check and see if the problem follows? I read that somewhere and it makes sense, I just don't want to mess anything else up.

Re: #3 & #5 Cylinder (No Spark) Tower of Power

I believe that should work, it will be easier than what i suggested!