Switch box blues

[Aggressive Machines]

Hello my ? is is it possible for both switch boxes to go out? Last weekend ran great all the way back to the trailer. set up all week went out today backed in the water to launch fired up running about 2k and when idle down to 900 it would die. wouldnt get on a plain and missing like crazy. brought home pulled plugs marked flywheel for each cylinder got the wife to spin over while checked each cylinder for fire the only cylinder firing perfect was 6, 2 would fire some nothing on 4 ,and nothing on 1,3,5. just seams weird that both could go bad. has anyone had this happen ?

Thanks in advance

Dave

[toyomirage02]

This happened to a buddy of mine the other day only he has no fire on 3 and 6 but he also ran the motor for a day or two on 5 cylinders so I'm thinking I haven't checked it yet but it may be the stator or from running it like that he may have burned up to never know till I check it out

[Aggressive Machines]

This happened to a buddy of mine the other day only he has no fire on 3 and 6 but he also ran the motor for a day or two on 5 cylinders so I'm thinking I haven't checked it yet but it may be the stator or from running it like that he may have burned up to never know till I check it out

Im thinking some trigger issues, going to check out more Saturday. Thanks

[TEXAS20225]

im thinking trigger myself just my .02

[LakeFever]

Im the new fish with one merc repair under my belt and Im going with stator or cracked flywheel magnets

[Cervelo777]

Keep us posted, the stator, Trigger, switch box, or coil, question seems to always be a riddle.

[HStream1]

Change the Flywheel and see if that corrects the problem before doing anything else. If it does the Hub Magnet has moved. its not uncommon here lately. These Flywheels are 20+ years old. Ive had 4 Hubs go bad in Three years and every time its acted different like trigger or bad Switch boxes. .

[Jay Smith]

I just freshened up one of my rebuilds of 15 years ago that was still running great but had mysteriously developed a squeak , like an upper bearing failing but had not lost an rpm in 15 years of trouble free service , I tore this thing down and miked every component to find nothing wrong , even the TDR reeds were perfect , long story short I polish the two tapers on the crank and flywheel and after a close inspection the flywheel hub was cracked completely thru from the bottom of the hub all the way thru the splines , so like Bud suggested don’t assume that the flywheel is ok , call me and I’d be glad to tell you a method I use to check flywheel magnets health..
832 597 2603
Jay @ JSRE

[Forkin' Crazy]

How often do triggers go out though? As far as a stator, I had one go bad and it took one of the switch boxes with it. So I just replaced both. When Merc parts go bad, they can take others with them is what I have experienced.

[Aggressive Machines]

I have an extra 40 amp flywheel, triggers, switch boxes , stator . Being new in to chasing electrical issues has got me stun . I was able to read in the manual and see that the trigger fires the switch boxes, yet the stator supplies high and low power. couldnt work on it yesterday, but about to go turn wrench's today. I had to order a DVA adapter so i cant really do much on checking parts unless someone knows a trick. I do thank all for the info help, and Jay I will call you sir on the flywheel check. Im just surprised how she ran good 1 weekend and the next went to crap before it got off the trailer. Im sure it does not matter but its a 1989 XR4

Dave

[Forkin' Crazy]

My Merc manual said (paraphrasing) if the DVA didn't show the problem, to start swapping parts. I know several good mechanics that keep a spare set of electronics on the shelf just to diagnose. I have a spare set as well.

[Aggressive Machines]

right where the trigger wires come out the fly wheel rubbed in to the wire insulation

[Aggressive Machines]

dont know what happen hereAttachment 419538Attachment 419538

[Aggressive Machines]

Well that was the main problem, I bought this bolt on a while back (xr4) and never noticed this trigger wire issue, installed another trigger and replaced the switch boxes (both) and she is hitting like she should . didnt get to go to the water but can tell the difference . Thanks to every reply it is all good info.

Dave