Power Pack Issue...

[bmbecker]

I have a question about my twin power packs on my '88 115hp Merc Outbrd. I had a power pack issue where I had 2 cyls no firing. NO SPARK. I swapped the two power packs around and the problems chased the original bad pack. Moving from for instance...cyl #4 & #6 to cyl #3 & #5 I believe. I automatically assumed that it was my power pack. I bought a couple from ebay and they were said to be in perfect working order. I put one of them in replacing the one that had the 2 non-firing cyl and it didn't work at all. Now all 3 cyl running on the new pack were not firing. Is it possible that I had something going wrong and blowing my power pack or is it just that I bought a piece of crap from ebay. I have one part left and im leary about putting it in if something could be blowing the packs. If there is something else anyone has for me to try I would be all ears. I have ohm'd the stator and looks to be OK. I dont have a DVA meter either but an entire arsonal of multimeters. Anyone that can help....shout it out. Im up for anything. Thanks....

PS - Is there some kind of test I can perform on my switchboxes that will allow me to see if my part is bad or not. I have yet to find that kind of test in all my research. THANKS!!

 

[Laddies]

Re: Power Pack Issue...

Disconnect the bias wire between the 2 black terminals on the boxes and check the spark if the bias fails in one box it will cause the other box to not work sometimes. Also if the engine is equipt with a idle stabilizer disconnect it.

 

[bmbecker]

Re: Power Pack Issue...

I havent read much on this idle stablizer but i will check into it. I went ahead and put the other switchbox in and I now have spark on ALL cylinders...im just nervous to start the motor now cause I dont want my last good switchbox to blow out. My biggest prob is that I dont know for sure if there was something wrong with the first one I put in or if I blew it out. Kind of hard to imagine that it would happen to blow out the one that I just replaced and not the other one though. I did ohm out the stator real quick again when I had the wires off and it ohm'd good according to my book. So, as of right now, I have fire on all cyl....do you suppose im good to start it and run it to running temp? Or, do you think I should check something else before hand?

 

[Laddies]

Re: Power Pack Issue...

You might OHM test the rectifier before start up to check for a short as that can ruin a stators output but is sounds like there was a bad bias in one of the boxes.

 

[bmbecker]

Re: Power Pack Issue...

Thanks, I will research that and give it a shot. I appreciate your help. I have seen alot of your posts and seems like you have a ton of experience with this kind of stuff...I totally appreciate your willingness to spread your knowledge with us less experienced boaters.

Thanks and have a great day and I will let you know what I come up with. I will say this to help out. I had a hard time keeping a charged battery before this all happend. I dont know if that would give you any other thoughts about where to begin looking.

THANKS!!

 

[Laddies]

Re: Power Pack Issue...

That does sound like a shorted rectifier here's the test.

 

[bmbecker]

Re: Power Pack Issue...

I tested out that old rectifier...didnt look good at all. So...I bought a brand new one...in a package and all...I tested it the same way and there isnt continuity at all. Is that test usually good on just the original equipment or is it a standard and the new part I just bought doesnt work either? I can imagine buying a new part in a package and it not working at all but I know it is possible. What are your thoughts?

Thanks, Look forward to hearing back from you.

 

[Laddies]

Re: Power Pack Issue...

The new rectifier should pass the test just as a used one would, remember there is only continuty one diretion thru the rectifier and if you reverse the OHM meter leads it won't give you a reading.

 

[bmbecker]

Re: Power Pack Issue...

Well, I have NO CONTINUITY with any test that I do with my new one. I am going to take it back down there and get a different one and try it.

 

[Laddies]

Re: Power Pack Issue...

If your OHM meter is OK then the rectifier is bad.

 

[CharlieB]

Re: Power Pack Issue...

Don't throw those old switchboxes away just yet.

Chances are that the first one you changed, with the non-sparking cy;'s is fine, that the second one you changed has the bad Bias circuit causing the first one to no-spark.

Mark the boxes "3 Cyl Only" They both should work fine on the 75 - 90 HP three cyl motors.

 

[bmbecker]

Re: Power Pack Issue...

CharlieB,

The first one I had was the original equipment. It ran odd cyl and the other one run the even cyl. I didnt have fire on 3 and 5 so I changed it out. Are you saying that it may not have been bad? What would have caused it to fire #1 but not #3 or #5? Also, if I changed it out with one of the new ones and it didnt fire at all...how do I test that one to make sure it is the BIAS circuit and not just bad? I put a new rectifier in and ran the motor for over 30min and everything is running good so far. The even cyl's still have the original box on it and the odds now have the replaced box that was in working condition. Im not doubting you in anyway, just trying to learn a little more about this all.

Appreciate your help and wisdom...

BMB