STX38 dies when I turn blades on

[Bison]

My guess is a seized bearing in a blade hub,that you can pull the other blade around is because its slipping on the belt,may lock up trying to turn the other direction cause of spring loaded belt tensioner action
Deck needs an overhaul.

 

[mark65]

i have this same issue, but also motor stops when i release the brake/clutch.. i feel there is something not right in the electrical area.. the local mower shop feels its the governor with out looking at at...but no posts on any forums suggests this with this mower ( black deck) that this is a major issue... motor starts ok fuel filter changed, have not pulled the carby apart..

 

[mechanic mark]

https://drive.google.com/file/d/0B_XZLMkMeCkdeHhPWE9Gd0pYdVk/edit?pli=1 see section 3 troubleshooting

 

[bertsmobile1]

If the engine slows down and slowly stops then it might be a govenor issue.
If the mower just stops dead like you turned it off it is an electrical problem.
Download the manual mark put a link to , correctly identify which variant you have then follow the electrical test proceedures, exactly as laid out in the manual.
Should be a couple of hours to find the problem.
And never go back to the place that profferd the govenor idea.