2012 Honda BF90 MAKING OIL?

Checked my oil today and was surprised to see my oil level was high. When I drained some oil to get to the right level seemed to be about half liter too much - 400 mls or so. I think I had it at right level when I changed oil about 15 hours ago. Engine now has 60 hours. Engine oil is dark and smells a bit like gas. Removed both thermostats to see if either was stuck open, very little buildup on them and when submerged in hot water both open. Question for reassembly are new rubber o rings essential, I have no dealer close by. Anyway thinking maybe from reading that it is possible low pressure fuel pump might have a leaky diaphragm. If that is a potential problem, could I test by removing the two bolts and then while holding it, pump the primer bulb to see if fuel appears on the shaft that goes into motor? I may be over reacting and maybe it was a simple overfill however I was careful doing the last oil change. Responses and suggestions would be greatly appreciated.

Anybody had a similar issue?

Anybody had a Honda with this problem or heard about it?

Yes, this has happened before. If you are in the USA and the motor is not a commercial motor, you should still be under warranty. There is a Service Bulletin that addresses this if you block thermostat is 60 deg C. This is a little unusual, where you have to keep a log before the dealer can call Honda to get permission to make the change.

Here is the instructions for the customer in the Service Bulletin.....

The customer must keep a log of the increasing oil level. Check the oil level beforeeach outing using the Oil Level Checking Guidelines on page 2. Measure the level of the oil on the
dipstick and record the date, engine hours, and level. Keep the log long enough to show a definite
increase in the oil level. Usually a 1/2-inch (minimum) rise on the dipstick is a sufficient increase to
allow action to be taken.

Here is a pdf of the form. Fill out the form to document the increasing oil level. Contact your dealer and also discuss with them to let them know what you are doing, so they can be ready for you when the log is filled out.

If it meets all the criteria and Honda ok's the work, the dealer will install a new head gasket and block thermostat.

Mike

Thanks very much, I will start measuring it. A few more questions, can you provide service bulletin number? Also is the solution a higher degree thermostat than 60 degrees Celsius? Final question it is interesting re the head gasket replacement any idea why that would be necessary? I really appreciate the assistance.

The new gasket has some blocked circulating holes to enable engine to heat up better.

The problem you have usually occurs if the engine is operated in cold water or running very slow for long periods.

Mike

Thanks Mike. Sent you a pm.