Oil mystery on 2004 Johnson/Suzuki 140 4-stroke

[ggduff]

Last spring I took my Johnson/Suzuki 140 4-stroke to my local mechanic to get an oil change. Since then I've been losing oil. About every 8-10 hours of operation it will overheat, go into panic mode (cap out at 3000 rpms) and even shut off. I'll check and sure enough I'm almost a quart low on oil. Unfortunately my low oil and no oil indicators are not working. Hopefully I have not caused any damage after this has happened 4 or 5 times. When I top off with oil and restart, everything is fine. What I don't understand is that with losing this much oil I have never seen one drop of it in the water. There is no evidence of it anywhere I look on, in or around the motor. I asked my mechanic about it and he said that 4-strokes burn oil. I'm not buying it. Any thoughts on what it could be or where I would even begin to look? Thanks for any thoughts or advice.

 

[JB]

Re: Oil mystery on 2004 Johnson/Suzuki 140 4-stroke

You may have damaged your engine by continuing to use it after you have evidence of serious trouble, ggduff.

First, get your oil sensors working. Then run a compression check to see if a.) there is significant damage to one or more cylinders and b.) the oil you lose is being burned because of blow by.

Other ways you could be losing oil is via damaged valve guides.

 

[reeldutch]

Re: Oil mystery on 2004 Johnson/Suzuki 140 4-stroke

how do the spark plugs look like?

if they look charcoal black you are burning oil.

you might want to do a decarb before you change the oil.

if its burning oil it might help to clean off the rings to prevent blow by.
if the plugs look clean and its not burning oil you have a oil leak somewere.

 

[JRJ]

Re: Oil mystery on 2004 Johnson/Suzuki 140 4-stroke

Definitely not normal. If you can't find a leak, then it must be burning it and I would think there would be smoke and oily residue at the exhaust. Check your filter and make sure he installed the correct one. Good luck.