Engine Snapper RER Knocking Sound

[Beks6745]

I have a Snapper RER Riding Mower with a 15HP Intex that has recently developed a knocking sound. I got it started before I took the video and it made the knocking sound, so out of fear of ruining the mower I quickly cut it; and I haven't been able to get it to start since. I have attached a video while cranking it. Sorry about the bad quality, I shot it with my phone. If any of you know what could be causing the sound, I would really appreciate it.

Thanks,
Ben

 

[Tommyboyxd]

I'm no expert but it sounds like there is some resistance in the cylinder. Have you kept up your oil changes and oil level? If there is something in the cylinder and you keep cranking it, the junk could get wedged in between the cylinder wall and piston and you will be like me trying to find a new engine. I wouldn't crank on it anymore until you can open it up can look inside.

 

[Beks6745]

Thanks for the reply Tommyboyxd. I am pretty sure I have kept up with my oil levels and changes. So it may be the junk in the cylinder, huh? If I open it up; and some kind of junk is wedged in between the piston and cylinder, I'm pretty much out of luck, right? When I shot the video, I took another one with the spark plug removed and it was able to crank under its own power. Yet, it still had the same knocking sound. Would this also be related to the junk in the cylinder? Thank you for your help.

Thanks,
Ben

 

[Tommyboyxd]

Man, I'm not sure now. If it is cranking easier with out the spark plug then it may be the lack of compression letting it crank easier and my best guess would be it is in the "lower end". But I'm really not sure.

 

[Beks6745]

I decided to just open up the head and see what's going on in there. I found out that my piston had chipped and the chips had been pounding up against the head cover with each revolution. They had dented the piston and head cover pretty badly, though. But thankfully, the cylinder itself was completely free of dents or scratches. Now the sound has completely disappeared. Thanks again for all of your help Tommyboyxd.







Thanks,
Ben

 

[Tommyboyxd]

So it is running okay?

 

[scott47429]

glad you got it fixed good luck with it

 

[Beks6745]

Thanks for all the help guys. I did eventually get it running. I also recently did a valve adjustment on it, and now it has been running high at 1650 rpm on idle; with the throttle all the way back at zero. If I increase the throttle, it jumps up to about 3700 rpm. I tried having the idle adjustment screw all the way in or out, but nothing seems to affect it. Any ideas on what it could be?

Thanks,
Ben