1991 Force 150 won't start

[slammin salmon]

10 years and 3 mechanics later. Unable to diagnos an intermitant starting problem. When it acts up it turns over fine but it won't fire. Not a puff of smoke from the exhaust and not even a cough when we shoot it with starting fluid. Everyone who should know believes it to be an ignition problem. By the way when it starts it runs great and doesn't give me a problem while fishing (I typically troll non-stop for 5 hours on average). It only misbehaves for me and NEVER for my mechanic. Any suggestions...I could really use some help.

 

[12Footer]

Re: 1991 Force 150 won't start

Bypass the kill switch,because these kill switches are junk. If it starts ok, replace it with an Amphenol(tm) rated the same.<br />Look for corrosin at the ignition swith too. I think yellow /red st, and orange/red (color code on my 120HP,maybee not same on yours).<br />Unplug harness going to CDs, and check for loose fit,corrosion..Take the female end,and a needle,and "re-stress" the contacts,by bending then inward just slightly. These old<br />"Ford-type" connectors are terrible for marine apps, and sure give us grief

<br /><br />It has to be a connection that is intermittant. A broken wire,bad connector,failing switch. Sorry I can't be more specific, but these are all suspect.<br /><br /><br /><br />------------------<br />Quater Horse; The kiddy ride in front of K-Mart.

 

[ODDD1]

Re: 1991 Force 150 won't start

Ya, SS it sounds like ignition....could be wiring in the boat,or something in thignition itself.....but to guess I need to know WHICH ignition you have....the earlier prestolite system or later merc battrery/CD system....what color are your ignition coils?

 

[slammin salmon]

Re: 1991 Force 150 won't start

Thanks oddd1 and 12footer...The wiring and connectors have been inspected from the ignition switch to the engine. I'm fairly confident it's not wiring. The ignition system is called "Thunderbolt CDI" and I think the coils are blue (but not totally sure on that one). The primary components consist of a ConverterBox, Switch Box, Trigger and Stator assembly as well as 5 coils. Two mechanics have said if they had to take an educated guess they'd start with replacing the Converter Box and then maybe the Switch Box, in that order (focusing on components that could create a completely dead ignition system as opposed to a misfire or rough running condition). Just this weekend I borrowed the service manual and a Multimeter from my mechanic to do the test sequence myself should it fail to start. Needless to say, day one of the weekend it started immediately so I went fishing instead and it ran great per usual, once it starts...appreciate any additional comments you might have.