Hello,
I have a 1989 Yamaha 20HP outboard that I bought used and is basically brand new as it was never used, maybe several tanks of gas burned. I am having a problem with #2 cylinder misfiring. Here is what I have done so far:
Before I tried to start:
-Cleaned out tank and lines, changed fuel filter.
- installed new plugs (two sets)
-removed carbs cleaned them completely, they were not dirty at all.
- oiled cylinders
Tried starting, ran, but a bit rough. Took it out for a run on my boat ran ok for 15 minutes and then dropped cylinder.#2 cylinder misfiring, pull that plug cap and engine hardly changes, but pull #1 plug cap and it dies immediately.
Since then:
-checked plug caps and wires, they are like new. Ohms check on caps OK (replaced caps)
-swapped coils around and problem remained with #2 cylinder
- swapped out plugs
- tried different tank with known good one
- checked timing both #1 and #2, both good and advances and retards.
- checked both coils with meter
- removed flywheel and inspected charge coil and trigger coils, again like new and checked with meter....ohms checked good
- rebuilt fuel pump, no change.
- removed carbs and cleaned again. Still no dirt
- checked all wiring connections all good. Cleaned up every ground I could see.
- removed flywheel again and swapped trigger coils around, no change.
-
This leads me to believe that the CDI box may be buggered..Can not find a CDI anywhere.
Added a few pics to show that this engine is like new and not a worn out piece of junk...lol
Please help as I am stumped.
I have a 1989 Yamaha 20HP outboard that I bought used and is basically brand new as it was never used, maybe several tanks of gas burned. I am having a problem with #2 cylinder misfiring. Here is what I have done so far:
Before I tried to start:
-Cleaned out tank and lines, changed fuel filter.
- installed new plugs (two sets)
-removed carbs cleaned them completely, they were not dirty at all.
- oiled cylinders
Tried starting, ran, but a bit rough. Took it out for a run on my boat ran ok for 15 minutes and then dropped cylinder.#2 cylinder misfiring, pull that plug cap and engine hardly changes, but pull #1 plug cap and it dies immediately.
Since then:
-checked plug caps and wires, they are like new. Ohms check on caps OK (replaced caps)
-swapped coils around and problem remained with #2 cylinder
- swapped out plugs
- tried different tank with known good one
- checked timing both #1 and #2, both good and advances and retards.
- checked both coils with meter
- removed flywheel and inspected charge coil and trigger coils, again like new and checked with meter....ohms checked good
- rebuilt fuel pump, no change.
- removed carbs and cleaned again. Still no dirt
- checked all wiring connections all good. Cleaned up every ground I could see.
- removed flywheel again and swapped trigger coils around, no change.
-
This leads me to believe that the CDI box may be buggered..Can not find a CDI anywhere.
Added a few pics to show that this engine is like new and not a worn out piece of junk...lol
Please help as I am stumped.