Almost new Masport Utility Mower belching white smoke

All my own fault but I have wrecked a new Masport Utility 460 push mower by using it way beyond it's intended purpose on a rural property.

Problem is that the tiny air filter kept blocking up because of the very dusty conditions and that meant going back to the house and washing out the foam filter and the plastic covers each time the mower slowed down.

Unfortunately the local dealer didn't have a spare complete filter assembly in stock and I had a time limit so I pushed on, washing the assembly out very frequently. Of course a stack of dusty grunge bypassed the blockage and the carb throat filled up with the dust. So off with the carb and petrol tank, cleaned things up, changed the oil and it was flying nicely again.

With about 10 minutes of work left to do it slowed to just above idling speed and was belching out vast quantities of white smoke and the spark plug was covered in black soot. The oil level was below the dipstick.

I expect I've lunched to bore, rings and piston and maybe the big end too but before I tear this thing down was wondering if there's a crank ventilation valve that's been blocked causing it to suck oil ?

B&S 148cc 450 Series Model 9T502 Type 2040 B1 Code 1105262 DOM May 2011

 

There is a vent, it is piped to the carburetor, but I suspect you are correct about lunching the bore. Might be worth popping the head off to see, but these aren't worth repairing when they reach this point. The breather assy is number 8 on this diagram:
Briggs and Stratton 9T500 Series Parts List and Diagram : eReplacementParts.com

 

Thanks for the advice and those very helpful links cheese, greatly appreciated.

I note oversize pistons/rings are available and cylinder boring is not a problem for me.

Won't be anywhere near the mower until end of this month, will let you know how I get on.

 

Took the head off and the bore is cactus.

I know I sound like a numpty ruining this motor so rapidly but I'm usually very careful with my mechanical devices.

Can get a new motor for reasonable price but won't do that until can organise a better air filtration system than the standard B&S

It won't be pretty but planning to use the bolt that goes into the guts of the nylon carb body to hold an elbow onto the carb inlet throat and run a snorkel to a LARGE oil bath type filter mounted to the mower deck. Then I'll be able to mow thru ant nest piles and dusty mounds with glee.

I've also acquired a brush cutter so the mower will be spared from doing the heavy duty work I was using it for :-} Thanks for the help.

 

OK, a few days after my last post rang the dealer who I bought the mower from. He said bring it in so he can have a look, agreed the motor was shot and said to leave it with him and he'd see what he could do.

Meanwhile found I could get a new short motor for a fairly low price.

My girlfriend was going to town on Monday and asked her to drop by the dealer to ask what's going on. He wheeled out the mower fitted with a bran new motor, no charge, fixed under warranty !

Happy camper ! ! !

Now that I have bought a brush cutter I won't be using the mower for anything else but cutting the lawn. I expect it will last me many years. I will be buying all my equipment and having everything serviced by that dealer in future.

THAT'S wot I call good customer service.