Slow crank

[Richard Shoback]

So I have an 05 Explorer. Sport trit's my boss's a kid down. The street supposedly was supposed to put just the transmission. That he went through the engine. The engine turns over very slow now. I was told that the kid told my boss that he had to widen the gap on the piston rings. I'm assuming that's why I have a slow crank.Correct and I will be doing a compression test.But I just wanted to know if you guys agreed with me.That that's more than likely one hundred percent the issue

 

[Richard Shoback]

Also, have put a new starter in. I was wondering, does the starter need shimmed?