# Has GAS; has SPARK. But won't start. Ideas????



## MonteB

I have an older Magneto Briggs & Stratton small engine hand garden tractor. It won't start.

I have gas. I have spark. Nothing happens. Doesn't even pop. What's the matter? 

Monte


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## billsmowers

MonteB said:


> I have an older Magneto Briggs & Stratton small engine hand garden tractor. It won't start.
> 
> I have gas. I have spark. Nothing happens. Doesn't even pop. What's the matter?
> 
> Monte


do you have compression have you tried fuel in the plug hole to bypass the carb
as you may have fuel in the tank but this may not get to the plug

bill


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## MonteB

billsmowers said:


> do you have compression have you tried fuel in the plug hole to bypass the carb
> as you may have fuel in the tank but this may not get to the plug
> 
> bill


Yes, I have compression. Yes, I've tried fuel in the plug hole. I'm stumped.


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## chuck_thehammer

First I would replace the spark plug...it could spark out of the engine but not under pressure with gas...
check spark timing...
place your hand over the carb and run the starter...looking for vacuum at carb...
are valves opening and closing completely...check cam to crank timing...


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## MonteB

chuck_thehammer said:


> First I would replace the spark plug...it could spark out of the engine but not under pressure with gas...
> check spark timing...
> place your hand over the carb and run the starter...looking for vacuum at carb...
> are valves opening and closing completely...check cam to crank timing...


These are good recommendations. I'll look at the spark plug and everything else you mentioned and get back here with results. Thanks.


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## MonteB

chuck_thehammer said:


> First I would replace the spark plug...it could spark out of the engine but not under pressure with gas...
> check spark timing...
> place your hand over the carb and run the starter...looking for vacuum at carb...
> are valves opening and closing completely...check cam to crank timing...


Update: I put in an new spark plug---nothing. 

It has a magneto, not a distributor. Can you time a magneto? 

This has a pull start, not a regular starter. Old engine. Can't see the valves without tearing it apart. Only has one piston, so I'm assuming it only has one valve. 

Any other ideas?
Monte


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## chuck_thehammer

magneto does have timing...just like a point system...or electronic ones...

yes only one valve for intake and one for exhaust...

if it is a flat head engine...remove the head...and check that the valves are closing and opening...seeing that you could check and see if they are opening and closing at the correct time compaired to the crankshaft...
a new head gasket is like $5.00


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## hdman97

MonteB said:


> Yes, I have compression. Yes, I've tried fuel in the plug hole. I'm stumped.




How much compression?


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## MonteB

hdman97 said:


> How much compression?


Have no idea. I just put my hand over the top where plug goes in. I'm going to next take the head off and see if everything is working alright.


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## hdman97

MonteB said:


> Have no idea. I just put my hand over the top where plug goes in. I'm going to next take the head off and see if everything is working alright.


That won't work, Check with a gauge.
May have a blown head gaset or bad rings.


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## 30yearTech

Post the Model Type and Code numbers off your engine please.


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## MonteB

hdman97 said:


> That won't work, Check with a gauge.
> May have a blown head gaset or bad rings.


Head Gasket is okay. Just looked. But can't see rings. Just piston. How do I find out if the rings are bad?? Because it does have compression....


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## billsmowers

MonteB said:


> Head Gasket is okay. Just looked. But can't see rings. Just piston. How do I find out if the rings are bad?? Because it does have compression....


do a compression test with a gauge or a leakdown test which will indicate if you have a leak and where the leak is


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## buy*david

*Needs*

You need fuel, compression, spark and they have to happen at the right time. It sounds like you have the first three so check timing. Briggs have a key way that can shear off holding the fly wheel in proper time. Depending on the model you might check by pulling off the fly wheel.


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## hdman97

buy david
I think the op is long gone.


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