[ladydi110460]

We have a 17hp B&S that ran fine for about 30minutes then backfired and died. We can restart for a minute or 2 before the same thing happens again. I hope someone can help. The tractor is about 9 years old but hasn't been used as much as it should. It is in mint condition except for this problem.
HELP!! My husband is ready to buy new.

[thebriggsdude]

Can you tell me if it's a single cylinder OHV (over head valve, has covers on the front that's stamped ohv)
OR flat head? Apposed twin? V twin?
I'm leaning towards a carb problem, which is a lot cheaper then buying new to fix.

[ladydi110460]

Ohv

[thebriggsdude]

Whens the last time the valves were adjusted?
I'd also like to ask if it starts right back up after it dies?

[ladydi110460]

The mower starts right back up. Sometimes it will idle great and then shut down with a "bang". I don't know if the valves have ever been adjusted. We really appreciate your help.

[thebriggsdude]

Man that's weird.. the easiest (well if you have a thickness gauge and a few tools) is to adjust them yourself.
http://faqs.custhelp.com/cgi-bin/faq...ted=1101860144


The bang, almost sounds like maybe fuel being dumped into the cylinder at a too high of a rate... (which means carb rebuild)
But its weird to start right back up indeed.

[ladydi110460]

Ok, adjusted the valves. Everything looks fine on them.Now it looks like its getting way too much gas and won't even turn over. What now? It acts like its flooding out.

[thebriggsdude]

OK, if it was getting too much gas... it would blow some black smoke.. is it indeed blowing black smoke? This would mean a carb rebuild... Because this may have a barely adjustable carb on it (epa regulated)

[ladydi110460]

No black smoke. It won't even turn over now after the valves were adjusted. Could the adjustment be wrong? At least it was turning over before then. The only reason I say too much gas is because the person that adjusted the valves said that. My husband says it acts like its not getting any gas now.

[thebriggsdude]

Yes too much gas will give you black smoke... husband is right, it sounds like not enough at this point (which means a carb rebuild)

As for the person that adjusted the valves... I'm hoping this was a small engine mech? And you had a receipt? Because he certainly misadjusted them... that link above is the page that tells you how, and gives you a link to the exact specs...