25hp no spark on bottom plug please help!!

toybuilder039

Petty Officer 3rd Class
Joined
Mar 6, 2011
Messages
84
I have a 1975 25hp model#25502B and for some reason I have no spark or very weak at best on bottom cylinder.I have tried switching leads going to coils then i get spark on bottom so I figure coil is good new points condensors even switched condensors but no change filed points cleaned points with contact cleaner and have replaced the pickup coil under flywheel but still has not fixed problem. I really need some advice so please help this thing is getting the best of me.
 

ultra353

Petty Officer 1st Class
Joined
Jun 21, 2009
Messages
388
Re: 25hp no spark on bottom plug please help!!

Check your kill switch wire(s) and all other wiring for chaffing, could be rubbed through somewhere. Disconnect kill switch and check for spark.
 

toybuilder039

Petty Officer 3rd Class
Joined
Mar 6, 2011
Messages
84
Re: 25hp no spark on bottom plug please help!!

I actually don't even have kill switch wires installed and I ran new wires from points to ignition coils thanks for the reply
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: 25hp no spark on bottom plug please help!!

did you switch the lead from the bottom cylinder to the top to rule out something in that bottom circuit?
 

toybuilder039

Petty Officer 3rd Class
Joined
Mar 6, 2011
Messages
84
Re: 25hp no spark on bottom plug please help!!

Yes I switched the wire going from the points to the coil and I got fire on the bottom then but then no fire on the top.Man this thing has me stumped
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 25hp no spark on bottom plug please help!!

You must have the points set Correctly on this mtr for the system to work properly. And they must be good and clean with no resistance. If I remember right one set of points works for the other for a ground circuit. It was a real horse S**t ignition system.
 

toybuilder039

Petty Officer 3rd Class
Joined
Mar 6, 2011
Messages
84
Re: 25hp no spark on bottom plug please help!!

I set both set of points .020 gap is that right or is there something else to try. I will check it out tonight to make sure gap is perfect thanks
 

toybuilder039

Petty Officer 3rd Class
Joined
Mar 6, 2011
Messages
84
Re: 25hp no spark on bottom plug please help!!

Well it was either one of two things not for sure which one though I sanded the pickup coil which was a new one though and I changed the ground wires on the ignition coils which were in between the coil and block to outside of coil I not for sure what worked but I finally have great spark will jump 1/2 inch no problem thanks guys.
 
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