1989 Force 85HP, no spark and then spark?

devl

Seaman
Joined
Apr 2, 2010
Messages
72
Sorry if its a long read, Ive summarized below if you'd like to help but dont like reading!! lol

Ok this is driving me nuts. We finally got my buddies 85hp Force running great, 4700 RPM at WOT and about 32 MPH on his 17' bass boat. All was well for 5 or 6 trips then we went out and ran WOT for about 5 minutes and shut her down for maybe 30 minutes, went to start and she would crank fine but thats it. We checked the fuel bulb and it was soft so we cleaned the inline filter out, checked the engine filter and it appeared she wasnt getting gas so we trolled in and took it home. On the muffs she fired right up...we chalked it up to something in the line and cleaned out the filter and lines properly. Took her out again today and ran her for maybe 10 minutes at WOT then shut her down for maybe 10 minutes then started her up and ran like 2 minutes at idle just to cross a river. Then shut her down for about 20 minutes and went to start and it wouldnt fire. I checked the spark on 2 and 3 and there was no spark. So we started trolling towards civilization for about 20 minutes and were about to switch batteries when we tried to start it just for the hell of it and it fired up. Took it back to the dock and let it sit for 10 minutes, started it and ran fine....shut it off for another 5 minutes, started and ran fine. Took it back out at WOT for literally like a minute and shut her off for about 45 minutes. Started and ran fine. The only thing I can think of is some kind of heat issue with the stator or maybe trigger?

Stator, trigger were just cleaned, ohmed and wires checked recently. 2 New CDI boxes, 1 new coil. Both batteries are new.

Summary:
1 - took boat out on 5-6 trips with no issues
2 - next trip, WOT for 5 minutes, shut off for 30 minutes, would not start
3 - took it home and ran fine on muffs, cleaned fuel system
4 - went out today ran at WOT for 10 minutes, off for 10, on for about 2 off for 30
5 - would not start, checked spark, none on 2,3
6 - let sit for 30 minutes then started right up
7 - ran for 10 min. on WOT, shut down for 10, started, shutdown, started and ran for 5 at WOT then shut down for 45
8 - ran fine on way back to dock
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
Re: 1989 Force 85HP, no spark and then spark?

Neutral saftey switch not being properly engaged or disingaged? Loose switch or shifter not position right.
 

devl

Seaman
Joined
Apr 2, 2010
Messages
72
Re: 1989 Force 85HP, no spark and then spark?

foodfisher: Thanks for the reply but if it was the neutral safety switch wouldnt it not crank at all? And we did try moving the shifter back and forth as well as check the safety switch. Is there something in the ignition switch, safety switch, or something else that would prevent spark to the plugs?
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: 1989 Force 85HP, no spark and then spark?

Check for worn or frayed wires under the flywheel. The trigger and stator wires that come out from under the flywheel can be rubbing on the flywheel. Also, loose or frayed connections on the 12 position terminal strip that connects the CD Modules, stator and trigger wires. If you don't have the terminal strip and have plug in connectors, check those for loose or corroded connections. Check the ground wire that goes from the coil mounting bracket to the block too.
 
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