# SPARKS COMING OUT OF THE EXHAUST.



## waterdragon1960 (Sep 28, 2012)

Howdy,

I own a 1975 manufactured Lawnmower with BRIGGS & STRATTON Engine, reconditioned around 5 years ago.
The last time the Machine was used, there were small sparks coming out of the Exhaust and the Engine started running erratically.
It won't start at all now and I suspect it's a Valve problem, as the Mechanic said 5 years ago, the Exhaust Valve needed replacing.
What are the symptoms of Valve trouble in a Lawnmower ?. It also smokes slightly as well.

I intend getting new Valves and Springs replaced. Could Valves not seating correctly cause these symptoms ?. What about the Ignition Points ?.

Hoping someone can help.

T.


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## Basementgeek (Feb 7, 2005)

Hi and welcome to TSF

The sparks are most likely caused by a engine that is running to lean (hot).
That in itself will eat exhaust valves/seats.

As you know the smoke is from rings not making a good seal. It could be just rings or cylinder bore worn or both.

Since you seem to like, like me, old B&S engines, I would pull the engine off and and take it a good small engine rebuilder and have them totally rebuild it.

BG


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## waterdragon1960 (Sep 28, 2012)

The Engine was rebuilt about 5 years ago, could the sparks be caused by Backfiring ?.
What are the symptoms of Valve trouble in a Lawnmower Engine ?.
Yes, I love the old B & S Engines with a passion, but Spare parts or old Motors are getting had to source.
If you give me your E-Mail address, I'll send some Pics of how the machine looked after the Chassis and Motor was reconditioned.


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## Basementgeek (Feb 7, 2005)

Yes bad intake valve could be the cause of the back fire.

Bad valve(s) cause loss of power, hard starting.

May want to check this link out, just for fun if it:

Antique Engines and Old Iron Tractors on SmokStak

You can post you pictures here if you want.

BG


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