force 150 91j series outboard QUITS/CUTS OFF on advnacing throttle

[bmaltb]

I have a Force 150hp 91 j series outboard with thunderbolt ignition (not prestolite)...one switch box, 5 coils. I recently replaced the flywheel and stator because the magnets disintegrated. Ran great for 5 d. Then all of the sudden it began immed dying (w/o sputtering or faltering) when I advance the throttle. Idles great. When I advance throttle past a certain point it doesn't sputter at all like starving for fuel or missing on a few cylinders, it just cut off/dead. Starts right back up in neutral. Any thoughts? Fuel seems unlikely (but I changed all filters and re-inspected lines anyway), Candidates would seem to be...converter box, switch box, or trigger assembly. Trigger assembly looks fine but the problem "seems" to be about when the timing advances and it rotates. Thanks for your help

 

[jerryjerry05]

Check all the grounds and connections.
​Unplug and use dielectric grease when plugging back in.
Permatex makes one.
That ok?
​Then go to outboard igniton . com
They have test procedures for your system.

 

[pnwboat]

Does do the same thing when on Muffs in the driveway?

 

[bmaltb]

pnwboat...I don't think I can get up to that rpm that motor cuts off at in neutral.
jerryjerry05...I'll give that a try, i don't have a good dva meter....just harbor freight volt meter...may have to break down and find one though or just start replacing expensive parts...not sure which is cheaper

 

[Derrick Fronckowiak]

From your description of the way the engine dies immediately without sputtering or faltering it almost sounds like something is grounding out the P-leads (primary leads or kill leads) on your ignition. In keeping with the old troubleshooting adage of "check the simple stuff first" this is an easy enough thing to check and eliminate as being a possibility. Not sure how your cabling is configured on your boat or engine, but I would start by tracing your engine ignition cabling through your boat paying particular attention to where your cabling is in relation to your throttle/shifter. Make sure there isn't chaffed wiring with exposed conductor that could be shorting to ground when you move your throttle/shifter. If your cabling runs next to/through your shifter or cabling mechanism on your engine, maybe when you shift into gear and/or advance the throttle to a certain point and your shift mechanism/throttle cabling moves, it could be making any chaffed ignition wiring contact and short to ground (effectively killing your engine the same way the ignition switch would). It's a simple check and a "must-do" before spending any money.

 

[bmaltb]

thanks derrick, great advice