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Starting B&S issues

cpc101's Avatar

Join Date: Jun 2009
Posts: 3

06-15-09, 02:14 PM   #1  
Starting B&S issues

Hi Folks,

I have a 15 HP OHV Briggs 28N707-0121-01 on a 1994 Craftsman Lawn Tractor that is killing me.

A couple of weeks ago I was cutting the grass and it died, as if somone had pulled the wire from the plug. It had been smoking so when I pulled the plug I found that it was bridged. I cleaned up the plug, put it back and tried to start it, it would fire up and die immediately.

I figured at this point it was time to get working on it. Expecting to be replacing rings, I pulled off the head and found that what I really needed was a new head gasket. I cleaned the deposits from the combustion chamber, replaced the head gasket, adjusted the rockers and buttoned it up and added a new plug. There was a lot of oil in the air cleaner so I replaced it too.

I still have the same situation, it fires and dies immediately. When I turn it over and pull the plug, there is gas on it, so I know I'm getting fuel and I checked for spark and I have that too (although it seems a bit weak, is there a way to check that?).

The only thing that I think is odd is that there is air chuffing out of the air cleaner when I turn it over. That would normally tell me that I am out of time. Since there is no timing adjustment on this thing, I am at a loss.

Any ideas would be greatly appreciated.



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cheese's Avatar
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Join Date: Jul 2001
Posts: 16,567

06-15-09, 09:41 PM   #2  
Did you open the lower part of the engine? Did you set the valves to .005" with the engine 1/4" past TDC?

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cpc101's Avatar

Join Date: Jun 2009
Posts: 3

06-16-09, 05:45 AM   #3  
No, I didn't open up the bottom end.

Can you explain the procedure for adjusting the valves at 1/4 past TDC?

I spun the engine until the intake was compressed fully and then set the exhaust, then spun until exhaust was compressed and set the intake.

Also, I'm wondering if the pushrods are mixed up. One is about 1/8" shorter than the other, one is steel and the other is aluminum. I don't think I mixed them up, but I guess the potential is always there.

Airman's Avatar

Join Date: Feb 2008
Posts: 755

06-16-09, 06:30 AM   #4  
The answer to your question is in this link:

How are the valves properly serviced?

cpc101's Avatar

Join Date: Jun 2009
Posts: 3

06-16-09, 08:59 PM   #5  
Excellent, I'll check it out.

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