Hi All! I have had this 1988 Yamaha excel on my 21ft Chris Craft Center Console for the last three years after picking the motor up dirt cheap because it had a bent prop shaft. After repairing the bent prop shaft, I had an amazing running motor for under $500. After running the motor for two years with minimal issues, I was running across a lake at about 4k rpm and the motor seized up. Upon tearing everything down, I found that the piston ring on cylinder 4 had caught on the exhaust port. After further inspection, I found that the oil injection pump had gone bad, resulting in engine failure.
Instead of trashing the motor I found that the damage to the cylinder wall was not nearly as bad as I initially thought. I took the block to the local machine shop and was able to clean and true of the cylinders without needing to re-sleeve or do more than a good boring on them. I ended up making the choice to completely rebuild the power head. #covid19project. I did not plan on the rebuild taking more than a month but life happened and I finished the rebuild about a week ago, 13 months after pulling the power head......... While for most organized and, well smart people would have taken a million pictures of where every wire, ground, bolt, nut, and washer went; I did not <insert facepalm image here>.
I now have the power head mounted, controls, fuel system, and electrical wires ran to the best I can remember and from the limited pictures I have found on the internet. I have every single manual ever made on this motor, to include the factory Yamaha service manual. Even with these resources, I feel like I am missing something somewhere. The engine turns over and I have power to the rectifier and CDI, but I am not getting any spark. I need some help and ideas on where to go now. My thoughts are:
Thanks for reading this novel of a post!
Instead of trashing the motor I found that the damage to the cylinder wall was not nearly as bad as I initially thought. I took the block to the local machine shop and was able to clean and true of the cylinders without needing to re-sleeve or do more than a good boring on them. I ended up making the choice to completely rebuild the power head. #covid19project. I did not plan on the rebuild taking more than a month but life happened and I finished the rebuild about a week ago, 13 months after pulling the power head......... While for most organized and, well smart people would have taken a million pictures of where every wire, ground, bolt, nut, and washer went; I did not <insert facepalm image here>.
I now have the power head mounted, controls, fuel system, and electrical wires ran to the best I can remember and from the limited pictures I have found on the internet. I have every single manual ever made on this motor, to include the factory Yamaha service manual. Even with these resources, I feel like I am missing something somewhere. The engine turns over and I have power to the rectifier and CDI, but I am not getting any spark. I need some help and ideas on where to go now. My thoughts are:
- Missing ground or other connection
- Bad CDI
- Bad YMIS
Thanks for reading this novel of a post!