ready4boating
Recruit
- Joined
- Jul 19, 2008
- Messages
- 1
Ray, I'm posting the latest on my 1986 Yamaha 200hp (non-YMIS).
My dad and I took the boat out to test it. Shortly after the boat planed, there was a sudden loss of power. We tried it again and the same problem came up--it's like half the boat's power was just cut-off. Since it's a two-stroke, we tested the oil level sensors (remote and main tanks) and they proved to be working. While running the engine at idle dockside I touched the port cylinder head and noticed that it was cool to the touch--not a good sign! We pulled all the plugs and got an intermittent spark (weak, when it did fire) from the port side. All the plugs on the starboard side had nice, fat, blue sparks. Further, when the engine was running, I pulled all three plug wires from the port side and it made absolutely no difference in engine performance. However, if I pulled a plug wire from the starboard side, then the engine had a tough time. Also, I should add that the carbs had already been rebuilt and the fuel pumps tested prior to this latest problem cropping up. Fuel pressure is fine.
We tested the charger coil, the lighting coil, and the pulsar coil, all of which tested within range (resistance test). However, the Ignition Control Unit and CDI are coming back with readings in the mega-ohms, when they should be much lower. I disconntected all wires going to CDI unit and Ignition Control Unit prior to testing. I looked for any visible ground problems, but could find none. Please let me know about testing for grounds.
For that matter, I'm open to any suggestions you may have. I am curious about voltage readings, but we don't have the right meter. I just want to make sure the ICU and CDI are truly fouled up before I spend a lot of money replacing them. What do you think?
My dad and I took the boat out to test it. Shortly after the boat planed, there was a sudden loss of power. We tried it again and the same problem came up--it's like half the boat's power was just cut-off. Since it's a two-stroke, we tested the oil level sensors (remote and main tanks) and they proved to be working. While running the engine at idle dockside I touched the port cylinder head and noticed that it was cool to the touch--not a good sign! We pulled all the plugs and got an intermittent spark (weak, when it did fire) from the port side. All the plugs on the starboard side had nice, fat, blue sparks. Further, when the engine was running, I pulled all three plug wires from the port side and it made absolutely no difference in engine performance. However, if I pulled a plug wire from the starboard side, then the engine had a tough time. Also, I should add that the carbs had already been rebuilt and the fuel pumps tested prior to this latest problem cropping up. Fuel pressure is fine.
We tested the charger coil, the lighting coil, and the pulsar coil, all of which tested within range (resistance test). However, the Ignition Control Unit and CDI are coming back with readings in the mega-ohms, when they should be much lower. I disconntected all wires going to CDI unit and Ignition Control Unit prior to testing. I looked for any visible ground problems, but could find none. Please let me know about testing for grounds.
For that matter, I'm open to any suggestions you may have. I am curious about voltage readings, but we don't have the right meter. I just want to make sure the ICU and CDI are truly fouled up before I spend a lot of money replacing them. What do you think?