Selling a boat and the buyers surveyor sent an oil sample off. This was after an oil and filter change and ran under a load for 1.5 hours. The test came back twice with 10% gas in the oil. This is a 1998 3.0 Chevy motor with a mechanical fuel pump. Boat had not been run under a load for over 5 years. I started it several times a year and let it idle long enough to warm up. I know it’s not good to let it sit. Too late. Did a compression test and all 4 cylinders tested 190+ or -. Plugs looked good. Don’t know if the choke was sticking but after adjusting it is fine. Doesn’t appear to have a float or needle valve issue as there isn’t any excess gas in the carb throat. I sent a sample to a lab last week but they could not test for fuel because I didn’t notice that they need to know what the viscosity of the oil was. Being a marine fuel pump it has a tube that runs to the carb in case of failure and after 25 years was stopped up so we think any excess fuel was forced back through the pump into the crankcase instead of the carb and burned off. I have replaced the fuel pump changed the oil and and filter, I am re having the last company testing it again but looking for suggestions for another lab that might be better.
Any suggestions on how to just test for gas. The surveyor tested it without knowing the viscosity so I’m not sure why knowing the viscosity is important. The other engine was tested twice and was fine both times without knowing the viscosity. He will re-test after I have made sure the problem is solved. I am not going to involve him until I get a clean test from a reliable company. I know Wix does testing but don’t know how good they are. Are there any local labs or suggestions who to use? Thanks
Any suggestions on how to just test for gas. The surveyor tested it without knowing the viscosity so I’m not sure why knowing the viscosity is important. The other engine was tested twice and was fine both times without knowing the viscosity. He will re-test after I have made sure the problem is solved. I am not going to involve him until I get a clean test from a reliable company. I know Wix does testing but don’t know how good they are. Are there any local labs or suggestions who to use? Thanks
