poland500ex19.5 modelpb1942yt

[sln]

when i start my mower when it is cold it back fiers & sputters until it warms up then it runs smooth i changed spark plug. did not help

 

[ILENGINE]

The only thing I can say is welcome to the world of emission compliance engines. It will only get worse from here. It is due to the lean mixture that the newer engines run on nowadays, and it is too lean to run correctly when cold.

I have worked on several that start and run that way until they warm up, not only your engine either. Others seem to start and run smooth within a few seconds after starting.

I am wondering what the long term life expectancy of the newer engines will be, because of the lean mix the engine runs hotter.

 

[pugaltitude]

Instead of pushing the choke in as soon as it starts, keep it on half choke for a while until in runs smooth without.
It can be a pain when showing new machines as it looks as though there is a problem when there is not.

 

[ILENGINE]

If I remember correctly there is no separate choke. And when first started sounds like the engine is overreving, so people tend to slow the engine down, which compounds the problem.