B&S 21hp burning oil

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Just picked up a used Craftsman YTS3000 with a B&S 21hp OHV engine. It's burning oil and little puff of blue smoke when I engage the blades. I pulled out the spark plug and it was caked in black krud. Other than the oil burning issue, it runs ok. Could this be the head gasket? Any other way to test this before I unbolt the head? Thanks.
 
Check and change the oil. Get the level correct. Overfill will make them smoke,. They do not take an even number of quarts.

Rod
 
Thanks, I should've added that in my initial post, I did do an oil/filter change....used HD30 oil. It's still burning oil more so under load.
 
With OPE engine smoking, always start by first checking oil level.

2nd: if the engine smokes under load, check wet/dry compression and note the difference.

There could be other possible cause of oil burning, such as (a ) worn rings, (b ) scoured cylinder wall, and/or (c ) excessive valve guide clearances.

Good luck.

Q.
 
Originally Posted by Mike141
Thanks, I should've added that in my initial post, I did do an oil/filter change....used HD30 oil. It's still burning oil more so under load.


I'd say the smoke could be some good cleaning going on. Sounds like the previous owner did zero maintenance. Give it a few more hours and change oil again would be my plan...
 
if the smoke doesn't bother you these things run forever anyway. keep good oil in it and cut away. You might switch to a synthetic with a high flash point for less smoke. maybe a 15W40.
 
Don't know any past history. Got a killer deal on it, it had a broken drive belt so the previous owner just bought a new tractor instead of a $20 belt. He did tell me it burnt oil. The thing that concerned me was how bad the spark plug looked when I pulled it out. I've noticed that these engines are known for blown head gaskets, so maybe this winter I will change that to see if it improves.
 
Only used it once so far so it's hard to tell, maybe you're about right with the 2oz per hour because I did have to add some when I was done with the lawn.
 
I would carefully measure the oil consumption before jumping to conclusions. I found the my 20 HP B&S twin will often times puff out some blue smoke on start up but uses very little oil. I also found out that the amount of smoke at start up is dependent on if you let the engine idle down of a minute before shutting off results in almost no blue puff at start up. If you shut the engine off while running at high rpm, then the blue smoke is very pronounced. Probably has something to do with the OHVs.if the oil pools in the valve covers. Ed
 
Is it a single cylinder? I do believe those would smoke pretty good if the head gasket fails. There's a small area between the cylinder and the area where the push rods run. It a small piece of gasket breaks loose it will make them smoke. I've seen it happen.
 
Do your due diligence of course but if it's a big single cyl Briggs, I'm betting it's a head gasket. They ow between the cylinder and where the push rods are.

Fire it up and get it hot, then pull the oil fill cap - if it blows loads of oil/vapor, then it's the head gasket. At least it's an easy fix.
 
Originally Posted by Elkins45
Do they make a 21hp one cylinder? I would expect it to be a V twin.

It is a v-twin.
 
I have a 22hp V-twin that's about 15 years old and has around 700 hours. I can expect to add a couple of ounces after a couple of hours of mowing. So far it still runs very well.
 
They do make a single cyl 21hp intek.
Can the op please clarify this?
The larger single cylinder Briggs Intek engines are notorious for blowing the head gasket between the cylinder and the pushrod galley.
I got one one that did this and it burned oil like crazy.
Head gasket was cheap, and pretty easy to change.
 
It is the single cylinder engine. I've never changed a head gasket before but watched it on YouTube. Seems pretty straightforward. What's the best way to clean the head/valves and such?
 
I looked up the 21 HP B&S engine. Originally listed at 21 hp but, was relisted as a 19 HP. It is a big single. Later b&S went to the Intek 20 HP Twin.
 
I've had several that burned oil, found that they oil control rings were sticky. I'd try a piston soak and some berrymans in the crankcase and see if it improves. Won't fix a worn engine or bad head gasket but it should free up the rings if they're gummed up.
 
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