# Power issues with a Briggs & Stratton 16.5 HP



## Firefighter615 (Nov 12, 2012)

I mowed my mother -in -laws yard the other evening and pulled the mower on to my trailer and drove about 3 miles to my house. When I started the tractor to take it off the trailer it was running very badly, so I took the top of the air cleaner off thinking that the filter might have been clogged and it ran better but still not the power that it should have. I have put fresh gas in it thinking that the gas might have been bad or a little water in it, but that didnt help either. So I took the carb off and opened it up and used carb cleaner in all of the passages to see if one of them had gotten clogged but nothing. The real strange thing is that it ran fine when I loaded it on the trailer but when I got home it didnt want to run very well. Please help...... Model is 42A707 Type 2238 E1

Thanks


----------



## jhngardner367 (Apr 5, 2011)

Check the oil for fuel.
It may have bounced enough to cause it to flood a bit.
Check the plug to see if it's sooty black,or black and wet.
If so replace the plug.


----------



## Firefighter615 (Nov 12, 2012)

I did change the plugs and gaped them at .030 but I have not looked at the oil. I will check that when I get home. Thanks for the information


----------



## jhngardner367 (Apr 5, 2011)

Is this an OHV engine,or a flathead ?
If it's an OHV,gap the plugs at 0.035,and flatheads at 0.030 .


----------



## Firefighter615 (Nov 12, 2012)

it is a flat head. It is so bad that when I try to ingage the blades it all but stops running. I have changed the oil this evening, still no help.


----------



## Firefighter615 (Nov 12, 2012)

it is a flat head. It is so bad that when I try to ingage the blades it all but stops running. I have changed the oil this evening, still no help.

There is a lot of gas be sprayed out of the top of the carb, I dont know if this is normal or not.


----------



## jhngardner367 (Apr 5, 2011)

Most twins have a bit of a fuel spray, but it's possible you may have a bad coil,or a spark plug or wire shorting.
Start the engine,and run it at full throttle. Then,CAREFULLY,short out first one side then the other.
If it dies,when either one is shorted,the opposite one is not working.
If it just slows on both tests,then it's not spark related,and you should check the timing key,and the fuel system.


----------



## Firefighter615 (Nov 12, 2012)

Well I found the problem. The Exhaust Valve Seat popped out of the block. I tapped it back in flush but if it comes out again how can I keep it from doing that? Thanks for all your help.


----------



## Firefighter615 (Nov 12, 2012)

Well I found the problem. The Exhaust Valve Seat popped out of the block. I tapped it back in flush but if it comes out again how can I keep it from doing that? Thanks for all your help.


----------



## jhngardner367 (Apr 5, 2011)

BEFORE you run it,take a small (3/16") flat - tipped punch and make punch marks all the way around the valve seat,in the aluminum,spaced 1/16" apart . 
This "peens" the aluminum,and holds the valve seat in.
If it isn't done,it will pop out,again,and could bend the valve,or crack the seat !


----------

