Gas straight into chamber...it starts & runs but then.......

[Academical]

Spent a day on Lockdown on a Flymo GL47 which was not running. Stripped carburettor to ensure jet were all clear. Also removed head and cleared carbon gunge. Re-assembled & tried to start. No luck!
Checked I had a spark which was good, so no issues with coil etc/electrics. Must be fuel issue then?
Tried the old trick of putting a little gas into the piston chamber after removing spark plug. Refitted plug, and the machine started right away. Left it running for 3/4 minutes to ensure it was drawing fuel. Fine,
Came back about 10 minutes later having cleaned up all tools and bench and pulled cord on mower.

Nothing, No hint of a start. Tried choke On Choke Off, Still nothing.

Must be something simple but as dinner was called from significant other, I hav eleft this until tomorrow morning. Meantime, any ideas or suggestions? (I didn't have time to try the direct injection gas again tonight!)

 

[Romore]

You know it has compression and spark, only thing left is carburetor. What engine? If it has the English Tecumseh good luck finding a diaphragm kit for the Dellorto carb.

 

[logert gogert]

even though you say you've looked at the carb and it was clean, still sounds like you have a carb issue

 

[logert gogert]

and i hate to ask, but is there gas in the tank?
( we've all done it.....)

 

[Academical]

Yes, Gas in the tank on a ratio of between 25:1 and 32:1. Air Screw opened on the tank and tap switched ON too! There was gas/petrol in the float chamber as well.

Romore suggests a diaphragm for the English Tecumseh engine & itt IS a Delorto FHC 2013 Carb though. There is a part behind the carb which I did not take off. It is a set of stainless steel flaps between the carb and the engine chamber in which the piston & drive are located. Could this be the diaphragm Romore is taking about? The flaps were moving when I gently pushed them with a thin screwdriver. As all looked sound I left that part well alone.

Appreciate the early replies. Thanks.

 

[Rivets]

Please post any engine info you can find. Brand, model and serial numbers. We need to know what you have in front of you.

 

[Romore]

Those are the reed valves, if they fail it won't run at all. The diapragm if it has one, I believe it does, is in the carburetor itself.

 

[Academical]

Those are the reed valves, if they fail it won't run at all. The diapragm if it has one, I believe it does, is in the carburetor itself.

Thanks for clarification.
Now sorted the problem finally so great for all feedback. Cheers.

 

[Romore]

So what did you find? It may help someone else.