Random Warning Buzzer Bf90

[jakepitsville]

Hey All from Down under in NZ again. Currently having a few intermittent issues with a 1997 carb BF90 and its really doing my head in.

Basically the warning buzzer comes on, and the engine goes into limp mode (ie drops a cylinder) during the odd trip out, sometimes its 15mins from the marine sometimes 20miles from the marina. There are no warning lights coming on (oil pressure green light is always on if I remember correctly.) The outboard water tell is running cool, the engine is not super hot to touch, I have oil etc. If I turn the engine off and leave it be for a few minutes it sometimes can fix the problem, other times if I just try drive it goes away after a few minutes or so. I have searched high and low to try and work this problem out playing with the wires etc to no success - I have even removed the wires from the the oil pressure switch and the wire from the thermostat over heat switch and the buzzer still comes on randomly.

Please help!@ Thanks in advance

 

[hondadude]

The common denominator is the CDI unit. It takes the input from the temp and oil sensors and decides to activate the alarm and initiate limp mode.

Pull the connectors going to the CDI and check for corrosion, clean, etc.

If you do not find anything there....hopefully you have a friend with either a BF75 or BF90 (any carbureted year) that may let you borrow their CDI unit to see if the problem goes away.

These CDI's are pretty bullet proof, I have seen a couple of the older ones do some unusual things, that only substituting a know good CDI could solve the problem.

Mike