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bf15a intermittently sounds severly out of time.

D

dmiller151

New member
Hi all. I bought a pre 1997 15hp outboard and it will run fine for a bit and then all of a sudden it will sound like the timing is way off. (missing,backfiring, unable to accelerate). During this time it will only idle but, very rough. Then just as sudden it will run fine for a minute. Any ideas?
 
Thank you for the reply. Yes, the belts and pulleys are fine and so is compression. Seems electrical to me, I was hoping someone else has had the same problem and figured it out.
Dave
 
Run with a timing light hooked up.-----Observe the flash of the light when it act up.----------Steady flash indicates ignition is OK.
 
Make sure you are using NGK DR6HS or DR5HS spark plugs. Do not use Denso plugs. You could have a cracked or intermittant spark plug.

Also, check the mounting of the spark coil. If the mounting bolt is loose, the spark will be intermittant.

One other issue that may cause a running problem are one of the connectors on the CDI unit. That is the part that is about the size of a pack of cigarettes on the top starboard side of the engine. When the engine misfires, squeeze the connectors with your fingers pushing them into the cdi unit. Sometimes the internal connections on the cdi fail. Squeezing sometimes will make a better connection and that will isolate your problem. Here is a link to a similar but a little more extreme situation ....
http://www.marineengine.com/boat-fo...-BF9-9-won-t-stay-running&p=568264#post568264

Mike
 
I think you nailed it Hondadude. If I mess with the connectors on the CDI it immediately runs good. I ordered a new one, I will see what happens. Thank you!
 
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