B&S 6.5 hp 'smokes'

[pbm]

My 10 year old mower with a B&S Intek 6.5 hp smokes out of the muffler and uses an ounce or two of oil during each mowing. It still runs perfect and doesn't foul the plug. What is usually the cause of this?

 

[daves66nova]

I've tried adding mmo to the oil before,but mine didn't smoke.Go ahead and do an mmo soak to see if the rings are stuck.

 

[Quest]

Originally Posted By: pbm
My 10 year old mower with a B&S Intek 6.5 hp smokes out of the muffler and uses an ounce or two of oil during each mowing. It still runs perfect and doesn't foul the plug. What is usually the cause of this?


smoking usually means 1 of the 2 things:

(1)bluesmoke: burning engine oil due to stuck rings or scoured cylinder wall. Both would typically require a rebuild or at least a teardown inspection to find out.

(2)black, sooty smoke, not oily: carb is running rich.

Q.

 

[pbm]

I don't think it's #2 because its more of a whitish (maybe bluish--I'll watch more closely next time) smoke. Also the plug isn't fouling. I assume the "MMO soak" involves letting it sit overnight?

 

[c3po]

I have a mower like yours that is 11 years old and it does the same thing, I did an Auto-Rx treatment on it and now I have some conventional oil in there to rinse everything out, I let it run for 1 hour today and there was no smoke, I think you just need to clean your's out. I have always run synthetic oil and after putting Auto-Rx in the oil came out black, you might want to try it. I would stay away from MMO, its old school in my opinion.

 

[pbm]

c3po: How much A-Rx did you put in? My sump capacity is 22oz.