V4 backfire at idle after timer base replaced

[Bitmess]

1995 Johnson 140 HP. I changed the timer-base and power-pack with new CDI parts. (Motor was surging at highspeed)
I found orange and orange black wires on stator cracked and shorted together when I remove the stator. Anyway. I repaired that too.
I timed WOT as per Joe Reeves method. I set the WOT timing 14 degrees BTDC. The manual says 18degrees. It starts right up but backfires loudly through the exhaust at idle. Above 1500 RPM, backfire goes away. This makes me think the idle timing is off. My Reeves guide says the idle timing will take care of it's self. The ears on the CDI timer base are a different than the ones on the OEM base, so I'm sure the timing is off. I'm not sure what to do now. I looked at the service manual. It says I need a test prop etc. to get idle timing correct. Help please.

 

[SparkieBoat]

Re: V4 backfire at idle after timer base replaced

the idle timing should be about 4 degrees ATDC. but you adjust it to set your idle at about 800-900 RPMs in the water about 1100 on muffs. the back fire is a timing problem, but if you got WOT timing set right then you should not have back fire at all. did you cross any of the power pack wires going to coils? also how do you know your original timer base was bad?? a surging motor could be plenty of things other than that. you have to DVA test in order to diagnose timer base problems. double check all of your wires going to coils and timerbase to power pack. also you should DVA test your stator..you really need to order the DVA adapter in my sig below and download the free troubleshooting guide also linked below. only then can you accurately diagnose your motors electronics.

 

[boobie]

Re: V4 backfire at idle after timer base replaced

The orange, orange/black wires run QS and SLOW from the power coil. QS cuts out after 1500 rpm. Seeing you had to repair the wires you may have something wrong in that system.

 

[Bitmess]

Re: V4 backfire at idle after timer base replaced

The original timer base was damaged by the previous owner. He ran the motor with a sheered flywheel key. The flywheel rubbed against the timer base. It seemed okay with the old power pack but the new CDI power pack didn't like it. As per CDI, I changed the timer base.

 

[Bitmess]

Re: V4 backfire at idle after timer base replaced

I am pretty sure about the wires to the coils but I'll double check. My son removed the orange and orange black wires leading to the power pack from the 0584428 - T/BLK,NUT&STUD AY, but forgot which went where. I'll double check that too.