Yesterday, I noticed some non typical behavior from my outboard, and I'm wondering what the forum members think. I have a '98 Suzuki 85 hp, converted to a jet.
At the Deshka landing, when I started my boat, I noticed that it was shaking quite a bit and the exhaust was sputtering. To me, these are classic signs of a plug misfiring or not firing at all. These signs weren't totally new, I saw similar symptoms back in May (last time I used it), just not as bad. I quickly changed the plugs, but the shaking persisted, enough that it made us decide not to head down river. I wen through steps to isolate the problem, including testing each plug for spark, testing each coil wire, testing each cylinder, etc. I concluded that one of the connections coming from the CDI (ignition computer box thing) was not working. Crud, 2 outta three isn't a good ratio, so w pulled the boat and headed for Southport in Big Lake, since they deal/service Suzuki. Got there, talked to a mechanic who agreed with my diagnosis, and found out a new CDI is $700!!! I decided to stomp around the parking lot while the shop was tracking down the part. A friend called, who used the boat in June while I was away, and told me "Oh yeah, it idled really rough, but ran great when I revved it up" HUH! How could that be if a cylinder isn't firing at all? So, I quickly threw the boat in the lake, and, I'll be ****ed, it did indeed run much better when in gear and opened up beyond idle. Weirdly, it didn't smooth out when I was using the choke lever to up the rpms, only when it was in gear. When I would slow down, the motor would idle smoothly for 5-10 seconds, then go back to missing and sputtering. What is up with all this? Could a motor run well on 2 out of three cylinders? Could I just have messed up the diagnosis? If so, why the rough idling?