Mountfield Mower / Briggs engine burning oil

[Alan]

I have a Mountfield Laser Omega 42 HP mower I've acquired recently which is producing clouds of blue/grey smoke and dripping oil from the exhaust silencer.

According to the sticker on it it's product code MP88901 made in 1995 with a

2.6Kw Briggs & Stratton engine.

I've only just got this mower and have no idea of it's history.

It seems to start easily enough but is either sucking oil from the sump and burning it, or may have had a load run into the cylinder from improper storage?

The oil level is between the dipstick marks, the fuel is fresh stuff and the smoke / oil dripping is irrelevant of the choke position.

So far I've only run it for a few minutes due to smoking out the neighbours!

Does this sound like a seriously worn engine, or just accumulated oil in the cylinder that should soon burn off?

If worn engine, what is the solution, will a new set of rings do it (does it have any??) or is the cylinder likely to be excessively worn?

Thanks in advance,

Alan.

[meow2222]

If it starts and runs fine, yet produces clouds of smoke, I doubt the oils in the cylinder. If it were it would mess with the spark plug too much. I'm more familiar with cars, and on a car engine the prime suspect would be a gone oilseal on an exhaust valve stem. If B+S uses the same sort of valve arrangement then this would be the no 1 suspicion. These seals cost pence, therye a rubber grommet that goes round the valve stem, with a small spring wrapping round it to keep it in place.

NT

[Alan]

NT, good thinking, I'll investigate. It starts on the first pull.

[Dave Liquorice]

Has someone added oil to the petrol like one would do for a 2 stroke?

If you dig about on the Briggs & Stratton website you should be able to manuals for your engine. You'll need the Briggs engine number and type that is stamped on the engine somewhere rather than a mower model number. The Briggs site has info on where to find the number(s).

[Alan]

Thanks, will look out the model number and then find the manual.

Alan.

[The Natural Philosopher]

[Alan]

I've flushed the tank with fresh fuel, so no to this one.

This sounds likely. Not yet sure if the guides are removeable - B&S "classic" sidevalve engine.

Agree.

I'll pull it apart over the weekend and investigate.

Alan.

[Pete Cross]

When I last had to change the blade on our mower ( don't have large pebbles as borders ! ) I laid it on it's side for about an hour, it smoked for about three cuts before it settled down again. Was it transported upright ?

Pete

[Clive George]

Is there a side you're supposed to lean it on? On our honda, if you put it on the wrong side, the oil leaks into the air filter.

(Having experienced the Honda, I'll never have another B+S engine)

cheers, clive

[Alan]

It ws transported horizontally in the boot of my car from the previous owner's to my house, however I don't know if he had it stored on it's side for a while.

I'll run it for a bit longer to see if it clears before investigaing further.

Alan.

[Alan]

I have a Honda engine'd generator - it seems a world apart in refinement compared to the Briggs! However, the Honda is OHV and teh Briggs sidevalve, so hardly a fair comparison.

Alan.

[normanwisdom]

Same here - run it longer and it'll probably clear. Mine did similar after I leaned it up to clean it.

cheers Jacob