Brute with B&S 675EX Series won't start

Good Day. Last June 2012 I purchased a Brute Lawnmower with a B&S 675EX Series engine. It is a simple push mower, with mulching, side discharge and bagging options. It worked fine for the rest of the summer until I put it away for the winter. I drained all the gas out of the tank and stored it in my shed over winter.
This past Saturday, I took it out to get it ready for cutting grass (Spring is late up here in Northwestern Ontario). I put in fresh gas, new oil, checked and cleaned the spark plug. It took numerous pulls to start it (no primer bulb) or throttle. It ran for about five seconds, then stopped. I could not get it running again. I put some gas stabilizer in the tank and tried with no luck.
Today I drained the gas, removed and cleaned the carburetor, put in a new air filter, checked the spark plug again, then reassembled everything. Put some new fresh premium gas in it and tried to start it. It started on the fifth pull, ran for about ten seconds, then quit. I cannot get it going again.
Does anyone have any ideas about what is wrong with it? I had no issues last summer and it was working fine when I put it away.
Specific info:
Brute Model: 7800891
B&S Model: 126M02-0675-F3
Engine built Aug 2011
Fresh Start Model
It is still under warranty and I have put in a contact request at Brute Power asking for their assistance.
All suggestions, ideas and comments are greatly appreciated, as is your time in both reading this post and your response.
Thanks,
Ron.

Good Day,
I called Brute Support today and as soon as I gave the tech guy my Product Number, he told me to get a different spark plug. Apparently this issue is well known to the company and the gentleman said this should fix my issue. Unfortunately I am out of town all week, so won't be able to check it out until Friday night. I will post my results then.
By the way, the correct spark plug for my model is RJ19LM.

Update to follow on Friday.
In the meantime, if anyone has any other suggestions, they are most welcome.
Cheers,
Ron.

I have not heard of that solution to the problem. I suspect you will need to replace the float needle and seat.

Rivets: I completely disassembled the carburetor yesterday and cleaned everything. The float and needle look brand new (only thirty hours of use last year). But I will certainly keep this in mind if the proposed solution by Brute doesn't pan out.
Thanks for the suggestion!

Success! I bought the spark plug that was recommended by the Brute Help person and the mower started on the second pull. It worked perfectly all weekend, I cut my lawn plus the two next to me and it started on the first pull each time I had to stop it.
So this issue is resolved, all because of a bad / wrong spark plug in the mower. It is kind of strange that it worked for three months last year, but wouldn't start this year with the original plug. And even stranger when I called Brute and the tech guy knew what the problem was as soon as I mentioned the model number of my unit.
FYI, the new spark plug is RJ19LM. The old was is an RJ2xxx - can't remember the rest of the model number.
The model number of my mower is 7800891.
Thanks for everyone's suggestions and ideas. One thing I will do is service my carb at least once a year, as well as use a fuel stabilizer even though I drain the gas tank each year.
Happy mowing to everyone!

Briggs have had a batch of engines fitted with the RJ2 plug and is causing lots of non start problems.
Set your gap to 0.020" on the RJ19LM.
The RJ19LM will be replaced by another plug when stock is available.
The new plug will be copper core and a hotter plug.

pugaltitude: Interesting news, thanks for the information. How will we know when the new replacement plug for the RJ19LM is out? Will they put out a general announcement or what, and how will they notify all owners of affected engines?
Cheers,
Ron.

So then, do you really need to use a "fuel stabilizer" if the remedy for the Brutes not starting is attributed to the wrong spark plug being installed? Is B&S providing replacement plugs to owners that haven't trashed their mowers yet? Thanks!

Re: Fuel Stabilizer and Spark Plug

B&S didn't supply a new spark plug, they just told me which one to get. Once I had that in the machine, it started fine and has been working fine ever since.

As for the fuel stabilizer, I don't think that had anything to do with my problem. However, I will use some in the last tank of gas I use before I store the machine for the winter. I usually drain the fuel tank, but I know there is still some left in the carb bowl. This way, any fuel left will have the stabilizer in it and hopefully won't cause any problems when I go to use it next year.

So, the solution for me was to buy the new plug. As for scrapping the machine, I was all ready to do that ..... but I managed to overcome my urge to do that. Glad I did, I now have a working mower.

Strange that B&S would ship units with the wrong plug, I expected better from them.

pugaltitude said:

Briggs have had a batch of engines fitted with the RJ2 plug and is causing lots of non start problems.
Set your gap to 0.020" on the RJ19LM.
The RJ19LM will be replaced by another plug when stock is available.
The new plug will be copper core and a hotter plug.

Click to expand...

I put in a e-3 plug but i am still having the same promblem, it will only run with the air cleaner off