9.9 running on one cylinder

[43_lx_merc_1996]

My 1988 9.9 is running on one cylinder. I have replaced both coils and both plugs... Still have the same problem. Ideas?

any help appreciated!

thanks

Chris

 

[faztbullet]

Go to CDI's website and download the troubleshooting book, test your stator and trigger and see if ok. Usually its a switchbox on the 2 cyider models that fails....

 

[fastjeff]

Has it got spark on both cylinders?

Jeff

 

[guyjg]

http://www.cdielectronics.com/support/

 

[43_lx_merc_1996]

Yes, I have a spark on both sides.

Thanks,

 

[racerone]

Look for an issue with reed valves or crankcase seals.---What does a compression test show?

 

[eclark53520]

Why did you replace the coils? Were they actually bad or were you just guessing? Did you have spark on both cylinders before replacing them?

How have you come to the conclusion that it's only running on one?

It's probably either a fuel or a compression issue if you have good spark but only running on one cylinder.

 

[43_lx_merc_1996]

I was just guessing on the coils. One actually had the incorrect part number. Spark was weak on that one as well. The motor ran the same with the lower coil completely removed...

The motor starts and idles perfectly.

Thanks,

 

[58beta]

Lower crank seal is gone. It won't show on a compression test.

 

[racerone]

This was likely fixed 10 years ago !