48 C running rough suddenly

[treesitter]

Greetings everyone. I'm having a little trouble diagnosing a sudden rough running issue with my C that started out of the blue, and it was just running/idling and not working hard at the time. It will "settle in" briefly for a few seconds or so but goes right back to roughness. I put a video on You Tube (link below) a video that starts with it running fine, then rough, then back to fine. I've done several easy things, trying to avoid harder possible fixes- cleaned screen in fuel bowl, fuel screen in fuel intake elbow on carb, drained carb and blew air through idle screw hole- but have not removed carb for a real cleaning/overall (which I have never done since getting the tractor). It is a Zenith carb. On the electric side I checked plugs and replaced, although all looked like they were firing but a couple looked like replacement was due; new rotor (since I had one); checked point gap, which was fine (I replaced plug wires/rotor/points/condenser/distributer cap a couple years ago). Played a little with the bumper spring screw on the governor some (it needed some adjustment when I first got the tractor) but no change/and the nut was tight/no movement to indicate anything different. So yes, I've thrown a hodgepodge of stuff at the wall hoping something easy would stick. Every time I listen to it I jump back and forth on it seems fuel related, then maybe firing issue. I am not a huge mechanic so if I have a compression or timing issue that will be more of an undertaking for sure for me. Any opinions welcomed.

NOTE THIS IS THE WORKING You Tube link (for those of you coming back for a second look:)

https://www.youtube.com/watch?v=1jSn3jTkN-0



Thanks, Andy

[Dale Finch]

It may just be me, but when I clicked on your link, I get "This video is private".

[Bob McCarty]

It may just be me, but when I clicked on your link, I get "This video is private".

I get the same thing.

[SamsFarm]

It may just be me, but when I clicked on your link, I get "This video is private".

I get the same thing.

Mee too! Lol! Private video!

Is your distributer cap have any corrosion on the contacts on the underside? Aluminum contacts on the distributer cap have been known to corrode, causing problems!

[treesitter]

Sorry all. I fixed the video to public. Honestly it was the first time I have ever uploaded a video on You Tube. I knew I should have waited until my kids got home!

[Dale Finch]

Just wait til the kids get home...still the same!

[treesitter]

I know that I think I got it this time! Try this link. Sorry.

https://youtu.be/1jSn3jTkN-0

[Jim Becker]

Reminds me a bit of a dropped valve seat, which I have never seen in a C-113 or related engine. A sticking valve might give a similar behavior (OK for a while, then stick for a while). I'd be tempted to take the rocker cover off and check for a troublesome valve.

[treesitter]

Thanks Jim and I will check that. I will say the longer it runs, the less it is willing to hit a smooth spot, nearly to the point it is all rough and no smoothness. After it starts, goes rough, sometimes a quick fast throttle will "slap it back" and run smooth for a moment. But like I said eventually it seems as though it can't find the spot, so to speak. Not that I let it run too long like that of course.

[Don McCombs]

Check the fuel tank outlet for a partial obstruction.

[treesitter]

Thanks Don. That would be the kind of fix I'm hoping for! But I will say when I put the bowl back on from cleaning the screen etc it filled up pretty fast. But I will still certainly check that.

I noticed in your tractor list you also have a Super A. I just got offered one for free, with free delivery. Sometime in May I'll be going over help get it out of the corner of the barn it's in. Other than it's not running, it's in good shape; kind of an oxymoron I know. He mentioned it was converted to 12V before he got it and he thinks he did something wrong 'with the whole positive ground thing', or something like that , and hasn't ran for couple years. I just need to get it here. I'm sure I'll have a post or two when I start dealing with it.

I would post a pic but don't know how....

Thanks for the tip

[SamsFarm]

I would post a pic but don't know how....

When your in the "full editor and preview" window where you type your message, right below the "save draft" button there is a "attachments" tab.

Click on the "attachments" tab, then "add files" button, then follow through with how it works on your phone or computer!

Hope that helps!!!

*Can never beat a free tractor!* *Running or not!*

[SamsFarm]

Even though you changed your ignition components, the possibility exists that one of them might be defective!

I hope you get it!

[treesitter]

I posted another video that's a little longer. I took the valve cover off and looked that over some, gave a few easy turns with the hand crank. All looked ok, but I'm no expert, and don't have the best view while turning crank. No blockage in fuel outlet from tank and cleaned up contacts some on dist cap.

https://youtube.com/shorts/oL5DWfikYLc?feature=share

[Don McCombs]

Good luck on the SA.