Trouble starting 129

jimbob200521 · #1 02-11-2014, 07:22 PM

I'm working with a 129 that's been repowered with a strong 14hp Kohler at some point in its life. It's always been a slow cranker but lately, I cannot, no matter what I do, get it to start. It has been being used for myQA42A since my 682 died and been doing a phenomenal job if it! But now...it won't start. I've got good spark, I've checked that much. It'll try to start, it'll kick over once or twice then it'll just keep cranking. Its getting frustrating because now that I have a new gearbox, I need it running. Any ideas, things I can check?

I've already removed and cleaned up all the grounds, I'm wondering about the carb? When it cranks white smoke comes out the carb. But maybe I'm wondering if there's water somewhere in the carb/lines? I just need a direction to go, thanks guys!

Cub Cadet 123 · #2 02-11-2014, 08:08 PM

It sounds like you have water in your fuel system somewhere. You might try dry gas or some carb and choke spray in the throat of your carb to get things started cranking over for you. I pre-mix my fuel with Marvel Mystery Oil and Startron before filling my fuel container, then add that to my cub. One of my 123's is slow to start in the winter, so I just spray some carb & choke spray (not much) in the carb and it fires right up. Hope that helps in some small way.

Cub Cadet 123

J-Mech · #3 02-11-2014, 08:16 PM

Just tore down a K301 motor today with the same problem. Intake valve not seating in it. Exhaust was burnt too. Don't think that had anything to do with it being a slow cranker. But it was why it was puffing back through the carb. It too ran fine, but wouldn't start.

Yosemite Sam · #4 02-11-2014, 09:40 PM

A lot of the time, in cold weather, the hydro tractors engine can not spin fast enough to start because the hydraulic oil is so cold and thick. Try jump starting it from your car or truck.

If that doesn't do it and it were mine, I would spritz a little starting fluid down the throat of the carb. and then try to start it. If it starts, even for a second, then you know that it's not getting fuel/enough fuel.

If it doesn't start, pull the plug and see if it's wet. If the plug is wet, it's getting too much fuel or it isn't getting fire at the right time.

An engine must have air, fuel, compression and fire to start. There must be the right amount of each and these things must occur in the right order and happen at the right time. In a nutshell, that's ICE 101.

Use a process of elimination to identify the symptom/s that is has, eliminate the symptom/s and it should start.

Billy-O · #5 02-12-2014, 12:14 PM

Look at the little and less invasive things to trouble shoot the hard starting problems before digging too deep like valves. For example, check your points (timing). Put in a clean plug gapped correctly

Another thing: As another poster pointed out, the hydro in cold weather can be pretty stiff on the starter. I find that starting with full choke and 1/3 throttle make it easier for cold starting. If I get a pop or two but no go, I back off the choke a little bit. That gets her going usually. Everyone's motor is a little different.

J-Mech · #6 02-12-2014, 12:19 PM

If I'm not mistaken, this is the tractor that I walked you through installing new points on right? So a tune up has been done? If that is the case, there are very few things that can cause a spit back out the carb. Timing, which can be ruled out because it has been done. Running lean could do it.... but in my experience, not when it is this cold. Either your coil is weak, or you have a bad valve. Check spark, but I'm leaning towards the bad valve.

jimbob200521 · #7 02-15-2014, 03:42 PM

Quote:

Originally Posted by J-Mech

Just tore down a K301 motor today with the same problem. Intake valve not seating in it. Exhaust was burnt too. Don't think that had anything to do with it being a slow cranker. But it was why it was puffing back through the carb. It too ran fine, but wouldn't start.

Well I got a chance to give her the beans today making room for more snow and while she performed very good, she didn't do great. When I'd load that thrower up, she'd almost sputter. I took just the bowl off the carb today before I ran it and there was some gunk in the bottom, I'm guessing that from using brake/carb cleaner, it cleaned gunk off and ran down into the bowl

Anyway, I cleaned it out, put new fuel line on it, and fresh fuel. Could the intake valve not seating only cause a sputter a full throttle leaning hard on the governor? And just out of curiosity, more to confirm, the spark plug gap for this motor is .35, correct?

Edit: Now that I know how easy it is, I'm debating removing and cleaning the head up on the 14hp in the 129 and if the valve is suspect to not be seating right, figured I could clean it up while I'm in there.