BoLongo
Active Member
I’m having electrical problems with backfires and fouling plugs. I replaced the Rectifiers and switched out the stator on one engine. Everything that can be tested is within specs. Mechanically sound 150 psi in all four cylinders. I went out today to test the boat before leaving for Havasu for the weekend.
Ran great for 5 minutes then started missing and random back fire both engines. At one point both engines would not rev over 3500 with the boat in drive. I disconnected the rectifiers with no effect on the problem, voltage seems to be stable and my battery is good. I changed spark plugs, the boat was running better but one engine would hit 7200 RPMs the other would stay at 6500. Then they switched and the opposite engine would hit 7200 RPM and the other engine would stay at 6500. All this is intermittent but seems to affect the port engine more. I am convinced it is the MPEM, probably the rev limiter.
Can I install an aftermarket CDI module to bypass the rev limiter? I read it works on a single 787 but can they be used on a twin engine set up. I do not want to spend the $1500 for a used MPEM, the CDI Modules run about $300 x 2. Everything else works except the intermittent ignition problems.
What aftermarket CDI modules work best for the 787? so far I can only find aftermarket CDI modules for the 1995 & 96 787s
Ran great for 5 minutes then started missing and random back fire both engines. At one point both engines would not rev over 3500 with the boat in drive. I disconnected the rectifiers with no effect on the problem, voltage seems to be stable and my battery is good. I changed spark plugs, the boat was running better but one engine would hit 7200 RPMs the other would stay at 6500. Then they switched and the opposite engine would hit 7200 RPM and the other engine would stay at 6500. All this is intermittent but seems to affect the port engine more. I am convinced it is the MPEM, probably the rev limiter.
Can I install an aftermarket CDI module to bypass the rev limiter? I read it works on a single 787 but can they be used on a twin engine set up. I do not want to spend the $1500 for a used MPEM, the CDI Modules run about $300 x 2. Everything else works except the intermittent ignition problems.
What aftermarket CDI modules work best for the 787? so far I can only find aftermarket CDI modules for the 1995 & 96 787s
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