K241 running rough

[grine_22 145]

So I recently acquired a nice 310-8. The grandpa-in-law said the carb was acting up.  Got it home, adjusted and it will idle just fine, I throttle up and take off and it will intermittently start stalling or backfire. But if I throttle back down to idle it runs OK.  Switched out coil condensor and plug as well.  Next step is the carb, either rebuild or find a new one.  Any other ideas or advice welcome. 

[tunahead72 2,549]

Personally, I would check the air filter first and probably replace the pleated paper element and the foam prefilter, and then see how it runs after that.

 

An easy thing to check is the main fuel needle, the one on top of your carb.  You can unscrew that completely (don't lose the spring) and spray it with a little carb cleaner to clean it off.  Depending on which carb is on your engine, that needle probably has several sets of very tiny holes along the shaft, they all need to be clear.  You can blow through one end and should get air flow through the other holes, but be very careful, that sucker is sharp!

 

If that doesn't help, I'd probably remove the carb, clean it thoroughly and rebuild it.  That could make a world of difference just by itself, but as long as you have the carb off the engine, it's also a good time to remove and clean the breather system and adjust the valves.  I'd also replace the entire fuel line and add a fuel filter while I was at it.

 

If that doesn't solve your running problems, and especially the backfiring, I'd remove the cylinder head and check for carbon buildup in the combustion chamber and on the valves and piston.  You would want to clean that off real good, install a new head gasket and torque the head bolts properly.

 

Has the engine oil been changed recently?

[grine_22 145]

I don't know how recent the last oil change was, I plan on doing that once I grab some oil, fuel line will be replaced, I figured I'd end up resetting the valves just wanted to hear other opinions 

 

[953 nut 60,224]

I have had great success with Seafoam clearing up this type problem on neglected . Use the liquid fuel additive in the tank and after removing the air cleaner, spray the Seafoam Carburetor Cleaner into the air intake while the engine is running at half throttle several times. It has done wonders for a couple of mine.

[pabird 40]

Hello all, 

I'm also having the same problem with a K341. It started to miss and cut out at full throttle while cutting. I found out that some of the wire connectors at the ignition switch were corroded. If i jiggled the wiring it would run fine. I replaced the connectors at the switch and the ignition switch. I also had a head gasket leak so i changed that at the same time and adjusted the valves. Also cleaned and adjusted the points and installed a new plug. Now it runs worse than when i started. It seems to die and then catch again and backfires. I haven't changed the coil and condenser or messed with the carb. yet. I'm wondering if I should go over all of the electrical connections. Could this be caused by a bad connection somewhere other than the ignition switch?

[grine_22 145]

I'll hafta give it a try. I know the I need to replace all the seals on the trans but that's no big deal 

[Tuneup 1,452]

Yeah, that carb is filthy. I expect that the filter is same and can handle the air on idle but chokes it on throttle. Still, backfire sounds like LEAN to me so the main circuit is in play and the needle clean is a good place to start. Does her running change when you open and close the top screw? A carb clean, filter replacement and carb adjust should work wonders.

 

pabird - the old trap of finding one thing that's bad which may or may not be the cause and then repairing it but finding others and going all over the machine could create an additional cause. Being lost is normal. Try to isolate it. I don't know your tractor model but you can disconnect the (+) coil wire and run a jumper wire from the battery (+) directly to it. If she starts and runs smoothly, the engine and its electricals are fine. It's then somewhere prior to the 12V wire to the coil. Electrics are always fun. Mine was red-necked to the point of distraction. If you were in Georgia, I'd help you with it. Move on down here with everybody else.

[gwest_ca-(File Mod) 11,510]

Got another condenser you can try? Have seen rough running and backfiring thinking it was fuel related and it ended up being the condenser. 

 

Garry

[pabird 40]

You got that right Tuneup! Shoulda fixed one at a time to see which one had an effect. Anyway this morning I got out the manual and adjusted the carb, Made a huge difference. Still has a very slight hiccup but not constant. Maybe a dose of seafoam or remove the carb, take it apart and clean it. Is it possible that the throttle plate bushings are worn allowing to much air in?

[grine_22 145]

Already put a different condenser on it and still the same issue. I'll fiddle around w the carb tonight

 

[Tuneup 1,452]

Hey PA, if you want to check the bushing, squirt a light stream of Gumout into the gap while she's at throttle to see if there is a change. Spray away from the exhaust and you can always use a less flammable spray like WD-40.

[pabird 40]

Thanks Tuneup, I'll give it a try tomorrow. Any kind of a change means excessive wear in the bushings? Are the bushings repairable?

[Tuneup 1,452]

That throttle bushing is a bother with controlling throttle. If yours has play, it's best to get it fixed. Maybe the listers will say it's very important - I don't know much about it in my lack of experience around Kohlers (I could only afford Briggs and Tecs in my minibike days). My personal K301 has more play than I like and I'll get to it I'm sure after all the other rigged stuff on my machine is corrected.

[953 nut 60,224]

15 hours ago, pabird said:

Are the bushings repairable?

@Ed Kennell did a little tutorial on how to do this and what is needed. I have put a drop of gear oil on the shaft to see if the bushing is sucking too much air.

[pabird 40]

Thanks Tuneup and 953 nut, I'll check this out asap. I did pick up a new condenser per gwest's suggestion but right now I'm fixing a garage door opener. Would rather be working on the horse!!!!!!

[Tuneup 1,452]

I hear ya. I have to power wash and seal the driveway today. I could have the Horse running by noon with the dash now done and the cables re-riveted and attached. Sigh.

[grine_22 145]

OK question for the more knowledgeable around here, I tore into the motor and got to the valves, clearance for intake was good, but exhaust was down to .16, would .02 difference possibly cause backfiring and rough running beins the exhaust isn't opening enough to burn all the fuel going into the chamber? 

 

Edited May 17, 2016 by grine_22

[grine_22 145]

Good news, adjusted the valves cleaned breather out new gaskets and she runs great.  One question tho, I didn't put the hood back on for a test run in case, I noticed the muffler got cherry red, I know they get warm but that warm? 

 

[wallfish 18,188]

Running lean will cause that. Try adjusting the carb.

[953 nut 60,224]

9 hours ago, grine_22 said:

muffler got cherry red

  Too lean, like @wallfish said.

[grine_22 145]

OK update, adjusted carb, still muffler gets red, had a new carb laying around, threw that on and I'll rebuild old one in the future for another tractor, adjusted it, new fuel lines and filter as well. Muffler still gets red.  Note though, only time I've been working on it is after dark and that's when I notice this, can't see it during the day.......any thoughts?

[sorekiwi 761]

Timing too far retarded can make the exhaust get really hot too

 

[953 nut 60,224]

Give this a try.

Kohler static_timing.pdf