no spark on 1 or more cylinders, but. . .

[james roach]

Re: no spark on 1 or more cylinders, but. . .

One word of advice here. A bad ground wire, a small knick in a wire somewhere, old plug wires that have corrosion on the connectors and such can drive you crazy. I know you have but double check your triple check before you start replacing parts. A qualified mechanic has seen this lots of times.

 

[BrianTindall]

Re: no spark on 1 or more cylinders, but. . .

Look near the shift linkage for the switch. Do you have the one power pack up top or two packs on the outsides of the block? Also, what year is this engine?

 

[farginicehole]

Re: no spark on 1 or more cylinders, but. . .

As far as I know, it's an '89 (model E150STLCEM, serial R08173240). I have one power pack, and that's on the starboard side. There is one "black box" up top, just aft of the stator, that is about 5" wide by about 3" long and around 1" thick. I believe this is the rectifier, but I'm not 100% sure. I can't find any part #s on it either. After what James said about that shift interrupter switch, do you really think that could be causing it since any one of my cylinders will cut out (not just the starboard three)? I guess I need to keep searching for bad connections and grounds, as he was suggesting.

 

[BrianTindall]

Re: no spark on 1 or more cylinders, but. . .

According to my '88 book, you should have two power packs (one on each side of the motor). If your problem does effect both banks then the problem is most likely farther up the chain (stator or timer base). If it only effects one bank, try switching power packs from side to side and see if the problem stays on that side or follows the pack. If it follows the pack then replace that pack. Maybe someone else has an '89 book to check if it's one pack or two.

 

[farginicehole]

Re: no spark on 1 or more cylinders, but. . .

Mine definitely only has one powerpack, and it's on the starboard side. I have the 35 amp system, but even the 9 amp version only has one powerpack at least for my '89 model. As I've already said, my problem does affect both banks intermittently, so since I only have one pack, I guess I still can't rule that component out. I think the stator and possibly the rectifier (since I also have intermittent tach problems) are up on the list of key suspects. James also has me wondering if there's still not a bad ground somewhere too though. I have a softball game tonight, so I won't get to do anything more until tomorrow night at the earliest. Thanks again for the replies! BTW, how is your motor running now?

 

[BrianTindall]

Re: no spark on 1 or more cylinders, but. . .

Mine is doing better. The miss is gone but the timing advance adjustment knob expensive part thing broke the other day. Picked up a new one and will try to install it Thursday afternoon. I am going to do a complete readjustment on the timing and throttle systems. I also raised the motor to the top hole. Didn't really make too much of a performance change, but now it blows out in the turns some. Going to drop it one hole the next time I pull it out.

 

[GatorMike]

Re: no spark on 1 or more cylinders, but. . .

I'm not a mechanic but I reciently had a similar problem with my 110 Johnson. I would lose spark in the lower right cylinder then it would run fine for a whild then I would lose the uper right. Since mine was on one side only I suspected the timer base and went to my $tealer (sorry just trying to be funny) to get a new one and the mechanic there told me it would more likely be the powerpack because they go bad much more often than the other components. I replaced the powerpack and it cured my problem. <br /><br />PS if he were truly a $tealer he would have let me replace the timer base since it costs twice as much as the powerpack and wouldn't have solved my problem.

 

[james roach]

Re: no spark on 1 or more cylinders, but. . .

I am almost certain your tach problems are unrelated to your spark problems. Lets fix the spark then we will diagnose the rectifier. I made an interesting discovery this weekend while trying to correct a tach problem I have been having. The tach wire connection in the terminal block looked good but I had a hunch so I cut the end off anyway and discovered the wire underneath the neoprene dip had turned green. I guess 17 years in saltwater will do that. I replaced the end and the tach started working correctly. I learned a valuable lesson from this.

 

[farginicehole]

Re: no spark on 1 or more cylinders, but. . .

Hopefully I'll get some time between now and the weekend to double check as many of the wires and connections as I can. I'm in fresh water, but it's certainly an old motor and the intermittent part sure is consistent with a bad connection or ground somewhere! Thanks for the advice, James. I'll keep you all posted. By the way, I should have skipped the softball game and worked on the boat instead. . . .