Engine running rough.

[1987_WHEEHORSE312 47]

So i need a bit of advice. My 312 ran great when I got it, put about 3 hours on it, and it seem to be running a little rough and dies off during an idle. Spark plug was shot, replaced it, replaced fuel filter, and air cleaner comes tomorrow. What else can I do, I dont have a shop yet or my tools at my house to tear the carb down, though it does run fine alot of the time. Has the original Kohler in it. May I also add I just bought it, ran through the gas that was in it, and then filled it up with fresh gas that I purchased a week ago, and filled my car up and the gas can at the same time.

[kpinnc 15,689]

If the plug was shot be sure and clean any corrosion from the plug wire. If your tractor is a 1987 with a Kohler it is likely a Magnum with magneto ignition. It works well and is far simpler than the older coil and points ignition. 

 

Can't speak for the weather where you are, but here in NC condensation is pretty rough. As such, I regularly drop the sediment bowl on the carb to clear any water or trash that accumulates there. From what I've seen, tractors with plastic fuel tanks are more prone to getting nasty at the carb bowl. 

 

Also, if replacing any fuel line, you're better off replacing all of it. And also ethanol free fuel will make your life easier. I know some will argue that they use ethanol all the time, but it draws moisture and has a much shorter shelf life than ethanol free. I never put ethanol in anything with a carburetor. 

 

Good luck! 

[1987_WHEEHORSE312 47]

1 minute ago, kpinnc said:

If the plug was shot be sure and clean any corrosion from the plug wire. If your tractor is a 1987 with a Kohler it is likely a Magnum with magneto ignition. It works well and is far simpler than the older coil and points ignition. 

 

Can't speak for the weather where you are, but here in NC condensation is pretty rough. As such, I regularly drop the sediment bowl on the carb to clear any water or trash that accumulates there. From what I've seen, tractors with plastic fuel tanks are more prone to getting nasty at the carb bowl. 

 

Also, if replacing any fuel line, you're better off replacing all of it. And also ethanol free fuel will make your life easier. I know some will argue that they use ethanol all the time, but it draws moisture and has a much shorter shelf life than ethanol free. I never put ethanol in anything with a carburetor. 

 

Good luck! 

Hey I appreciate it! When I changed the filter out and the shut off, I looked the the line and it looks newer and isnt super hard. Ill pull and clean the bowl out and someone suggested I run seafoam through it 

[squonk 44,594]

If it's a Magnum have seen a lot of crazy issues with the coil. A lot of them act like a fuel issue but it's the weak coil. 

[1987_WHEEHORSE312 47]

1 minute ago, squonk said:

If it's a Magnum have seen a lot of crazy issues with the coil. A lot of them act like a fuel issue but it's the weak coil. 

Are new coils easy to find? Im gonna do a fuel system treatment first just to see, cause it runs find at a higher idle 

[squonk 44,594]

I never needed to buy one but other members have had coil issues. @Racinbob

[Racinbob 12,233]

I purchased a mint 314-H 100 hour unit that gave me fits. Seemingly it was an obvious fuel issue. Like clockwork it would shut down as my wife was mowing. I replaced everything fuel related, rebuilt the Welbro carb twice and then replaced it, electric fuel pump. Didn't change a thing. I put a muffler 'test pipe' on it.  I was hesitant to go with a coil because I had only checked for an oem coil at well over 2 bills. Not something I wanted to try as a test. Then I found a knock off coil and tried it. BINGO! I had tested the original coil and it tested good. The heat build up apparently did the number to it. 

[1987_WHEEHORSE312 47]

56 minutes ago, Racinbob said:

I purchased a mint 314-H 100 hour unit that gave me fits. Seemingly it was an obvious fuel issue. Like clockwork it would shut down as my wife was mowing. I replaced everything fuel related, rebuilt the Welbro carb twice and then replaced it, electric fuel pump. Didn't change a thing. I put a muffler 'test pipe' on it.  I was hesitant to go with a coil because I had only checked for an oem coil at well over 2 bills. Not something I wanted to try as a test. Then I found a knock off coil and tried it. BINGO! I had tested the original coil and it tested good. The heat build up apparently did the number to it. 

Interested, im gonna try seafood when I mow in a week or two and see what that does. If that doesnt work ill tackle the coil

 

[953 nut 62,133]

1 hour ago, 1987_WHEEHORSE312 said:

gonna try seafood when I mow

Not too sure that will make the engine run any better but I'm always in favor of seafood.          

[Bar Nuthin 1,480]

1 hour ago, 1987_WHEEHORSE312 said:

gonna try seafood when I mow

 

Autocorrect can be your worst enema.

[1987_WHEEHORSE312 47]

18 hours ago, Racinbob said:

I purchased a mint 314-H 100 hour unit that gave me fits. Seemingly it was an obvious fuel issue. Like clockwork it would shut down as my wife was mowing. I replaced everything fuel related, rebuilt the Welbro carb twice and then replaced it, electric fuel pump. Didn't change a thing. I put a muffler 'test pipe' on it.  I was hesitant to go with a coil because I had only checked for an oem coil at well over 2 bills. Not something I wanted to try as a test. Then I found a knock off coil and tried it. BINGO! I had tested the original coil and it tested good. The heat build up apparently did the number to it. 

Interesting. Ill have to keep an eye on it. 

[1987_WHEEHORSE312 47]

16 hours ago, 953 nut said:

Not too sure that will make the engine run any better but I'm always in favor of seafood.          

Seafoam, though a lobster tail wouldn't be a bad option either 🤣🤣

[1987_WHEEHORSE312 47]

16 hours ago, Bar Nuthin said:

 

Autocorrect can be your worst enema.

🤣🤣

[peter lena 9,452]

@953 nut   https://www.google.com/search?q=seattle+fish+market+throwing&rlz=1C1CHBF_enUS866US866&oq=seattle+fish+&gs_lcrp=EgZjaHJvbWUqBwgFEAAYgAQyCggAEAAY4wIYgAQyBwgBEC4YgAQyBggCEEUYOTINCAMQLhivARjHARiABDINCAQQLhivARjHARiABDIHCAUQABiABDIHCAYQABiABDINCAcQLhivARjHARiABDIHCAgQABiABDIHCAkQLhiABNIBCTE3ODUwajBqNKgCAbACAfEFvk_42bGC4zLxBb5P-NmxguMy&sourceid=chrome&ie=UTF-8   ever been in seattle ?  incrediable  alsakan  fish  sorting spot , also boeing aircraft  factory tour , the  chinese food area  , wear loose clothes , it helps , space needle , pete

[1987_WHEEHORSE312 47]

***Update***

Sprayed seafoam in intake, put some in gas take and performed a slight adjustment to my idle screw and main throttle screw on the carb and she runs perfect! 
 

[peter lena 9,452]

@ e312  ,  that sounds like a  REPEDITIVE  something that you should  regularly do !  simple as it sounds , regularly  try experiments  with   anything   issues , thats how you can  really  dial in reliability , and  minimal issues . years back had regular  fuel related  problems , commonality  was  fuel hose break down , clogged filters  . cleaned out tank  , add filter at tank  , all new hoses , another filter  close to carb , also started  using , STA,BIL  fuel storage treatment  , ounce or two  , to every tank top off . never had another fuel related  anything on my 3  horses .  another glairing  gain  is that all my fuel filters and fuel bowls , are clean/ clear  . just started up stand by generator  , instant start  , clean fuel bowl . regularly suggest this , because its been  bombproof  ,  another thing  I don't  have issues with is spark plugs .  only suggest what  has been  consistently  working for me .  pete