Grumpy K301
 

I had my 125 out today working on blowing the yard clear of the 12 inches of heavy wet this evening. it was working fantastically, chewing up even the heaviest stuff. Got the driveway all clear after about an hour and a half, then pulled it off to the side so I could move cars and do the final cleanup. Here's where things got interesting. First, I idled it down slowly, and it started to surge a little bit. nothing serious. after moving cars, I slowly throttled it back up and began throwing the last little bits. However, as soon as I touched anything, the engine would nearly die, and cough and backfire a few times before coming back up. any time engine got a load on it, same thing. I decided to call it a night and put it away, letting it idle down for about 5 minutes. My father came by later and we talked about it, and he thought perhaps it was running lean, possibly due to vaccum building up in the tank from the cap vent not working right. I'll test that this weekend. after he left, I had another thought. Maybe, when the tractor sat idling (it was approx 10 minutes, give or take) i had built up some carb ice, like what can happen in a small plane. it would throttle back up with no load, but no power when needed. any thoughts? it was pretty "humid" here, right on that snow/sleet mixing line. it was running absolutely perfect before idling down. Let me know what you guys think! I won't get to tinker til sunday, so I'll update with my findings then.

That sounds nearly identical to the problem I'm having with my "O". Except the O is pushing instead of throwing. Idles fine, revs up somewhat fine, then I put her in gear and it starts acting up. I have a thread going, with some great info. Maybe between the 2 tractors, we can isolate our problems. Good luck with you're 301.
Rick

Don't know if this helps or not and I don't know why (cold air?), but my snow thrower, which normally works fine would idle rough under load, so I put the choke on 1/2 and it ran just fine under load. Worth a try, maybe?

Cub Cadet 123

Sounds like you could stand to turn your highspeed needle out 1/4 to 1/2 of a turn.

As for the original post we probably need some more information. It could be carb adjustment or ignition system trouble. Try to play with your choke to see if it improves things.

well, didn't get the chance to tinker this weekend, got called in to work on Sunday so lost my wrenching time. had to bartend for a funeral... THAT was a first. :beer2:

anyways, yes, I do think mixture may be a bit too lean, I will try backing out the high-speed screw a bit and see what happens. before I do though, I'll try using it full bore like before and see if there's a power drop or not. As for more info, the engine has never been opened up as far as I can tell. when I bought the tractor it had a bad coil. it got new everything besides the spark plug, which looked good and fairly new. It's run flawlessly since I first got it running 2 years ago.

That night, it ran at full throttle for and hour and a half, never missing a beat throwing heavy wet snow. I then parked and throttled it down to idle for about 10 minutes. it surged a little bit initially when idling down, but stopped after about half a minute. I then throttled back up full throttle without issue, but when I put a load on the tractor it wouldn't maintain power, rather it would backfire a few times then almost stall. once I backed the tractor away from the snow pile it would throttle right back up.

I'll hopefully get some time before thursday (our next snow forecast) to check it out.

Sounds like a fuel issue of some sort. Try adding some SEA FOAM in the gas

That is the last thing I would use.

My tractor with show thrower on it has the same issues. Engine is sucking some snow/moisture in it. Add a little dry gas to the fuel. That works for me.