Re: Onan genset trouble code "seven blinks"
If you put a zip tie around the impeller and tighten it it makes it pretty easy to insert the impeller. Start with the zip tie toward the end you are inserting.The zip tie slides off as the impeller is inserted. We apply some Lanocote on the metal spindle as well and use silicone grease or the Jabsco grease on the impeller. We keep a zip tie in our kit. They can be released with a jewler screw driver and re-used.
Related--we are big fans of the Impeller Puller sold by BayShore Marine in Bert Jabins Yacht Yard in Annapolis. We use a rag over the edge of the raw water pump if any prying is applied. http://bayshoremarineengines.com/impellerpuller.aspx They are also our very favorite for any Yanmar or Onan parts.
Whenever our generator is not in use (even at anchor now due to solar panels) we close the seacock and run fresh water into the sea chest and through the Onan cooling loop. We also do this with the AC pumps, anchor wash, toilets, Dessalator feed pump,and Yanmar (and the corrosion prone manifold in the process) whenever we can--especially after docking but it is also easy to do at anchor or even underway.
Fresh water helps disolve deposits and salt, decreases galvanic action, and helps eliminate marine growth. We also think that the dried out salt crystals and deposits on the above-water-line Onan raw water pump contributes to the short life of Onan impellers. When we begin to desalinate water we usually divert (using a 3 way valve attached to a short hose) the first 3-4 gallons into jugs stored on the floor of our engine room. The TDS usually diminishes during this period and any odor would be reduced plus we have a chance to manually test the water with a TDS meter and observe for any desalination system drips. This becomes the water we use to flush the generator when we are done using it. We almost always make fresh water when using the generator.
Bob and Suzanne, KAIMI SM 429