425 Quit in 7 Degree Weather

[lyle425]

My John Deere 425 (Kawasaki twin OHC) tractor started missing after about 30 minutes of plowing in 7 degree weather this morning. It then just quit and would not re-start.

It's been a very reliable machine and has about 950 hours on it. I have used it without any issues for 2 years although this is my first winter plowing. I'm thinking fuel icing, etc. I treated the gas with Stabil but not an anti-freeze at the beginning of winter (I'm learning now that Stabil does not include an anti-freezing agent.)

So I went ahead and treated the gas with (anti-freeze) solution and checked fuel filter and pump; both work great. I also checked the spark plugs and it has good spark. I sprayed some cold engine start spray directly into the carb and even tried a little raw gas to prime it.

Now when I crank the engine it sounds like it wants to start but in a 5 second crank period I only hear the engine combust 1 or 2 times. I'm a little nervous about cranking too long and burning up my starter, and I'm not sure if I should choke it or leave the carb wide open. At this point, I'm thinking it could be flooded so I decided to stop and come inside, warm up and post to this forum. Any ideas?

 

[thatguy]

Just out of curiosity.. Are you using a winter weight oil in it??

Brian

 

[lyle425]

Yes Dealer recommended 10W -30

 

[lyle425]

Almost seems like bad gas -- everything seems to be working except combustion. I cleaned carb and still only 1 or 2 pops in about 5 seconds of cranking. -- and the combustion doesn't build. It fires and that's it. Any other thoughts out there on what's wrong. Again this tractor started and ran every time I turned the key fro the past two years - although this is first time it's been used by me in such cold weather. It has however been in my garage all day -- 27 degrees -- and still the same performance. Could it be the gas?

 

[Matt_Jr]

Try changing the spark plug/s. Also put the battery on a trickle charger-a fully charged battery will give better spark while cranking. If you think it's flooded it's possible that the float in the carb is sticking. Try tapping lightly on the bowl with the handle of a screwdriver. If that works you may need a carb rebuild. If not check compression. Keep us posted.

 

[Matt_Jr]

If it's been a while since run last the cylinder walls could be dry. Squirt a little oil down in the cylinder through the spark plug hole to raise the compression back up.

 

[lyle425]

Thanks for responding Matt. Actually, I have used the tractor quite a bit as of late -- for several hours yesterday - it ran fine - even with the cold weather. Today it was even colder (single digits)-- after about 30 minutes it sounded like it was missing or only running on one cylinder. I headed for the garage and it quit, and hasn't fired back up since. When I first tried to restart it it sounded like the flywheel wasn't even turning. (Is it possible that 10W-30 oil wasn't the right grade for such cold weather? ) In any case, the starter is now engaging the flywheel and I have been using a jump from my car to keep the battery charged up throughout the day. Should I try charging the battery back up anyway?

BTW - I put new spark plugs in - seem to be OK, and I disassembled and cleaned the carb - everything looks good.

 

[Treemonkey1000]

Are you sure it isn't the carb icing up? That is a gas machine right? I had a truck do that when the heat tube from the exhaust manifold came off. I could drive for a little bit. Then the venturi in the carb would freeze up.

 

[lyle425]

Thanks for responding. I doubt it because I have been working on this tractor in my garage most of the day - about 28 degrees -

 

[jpm]

have you checked spark?

 

[lyle425]

Yes - I am getting spark out of plugs -

 

[john_bud]

Iced carburetor.

Probably have some fuel passages blocked with ice. Heat the tractor up. A space heater aimed at the carb and a blanket over the tractor -- with care that things don't get too hot or touch the heater!!

2-3 hours at 45-60F will probably melt the ice and the stuff you added will work.

jb

 

[lyle425]

Thanks for responding - Do you think this is the case even though I dis-assembled carb and cleaned? - I seemed to be able to blow through jets - although I couldn't actually check all of them

 

[keeney]

In my experience, 90% of all small gas engine problems are carb/fuel related, and almost never the spark, timing, or valves. If the battery is cranking it over, there is almost certainly enough voltage for the ignition to make good spark.

I would suspect bad gas or water in the gas and/or icing in the fuel line. It will take quite a while (like until spring) for an iced carb or fuel line to thaw in a 28 degree garage! Try cranking the heat up in the garage well above freezing for several hours.

Does the gas coming out of the carb smell like gas? If you suspect its bad, drain it all, including disconnecting the fuel line to the carb and draining the float bowl and replace it all with known good fresh gas. A good way to check that the float valve is working and good fuel is flowing through the whole system all in one shot is if the float bowl has a drain on its bottom - you can just drain the whole system from there.

It could also be some contaminant plugged the oriface, jets, or float valve in the carb, but you said you checked all that.

Also, check for any linkage or springs that may have come loose from the carb. Verify that the throttle and chaoke are in reasonable positions while you are trying to start the engine.

- Rick

 

[lyle425]

Wow -- I appreciate your confidence Rick! Just about everyone I talk to is leaning towards this answer - (too bad I can't get my tractor through my front door to warm it up - Somehow I don't think my wife would appreciate it in the living room.)

I connected the float (top half) part of the carb to the gas line and gas flows right through it so no problem on that end of the carb - could I still have a problem elsewhere in the carb ?

 

[keeney]

It only takes a very small piece of ice or some other contaminant to plug the oriface that feeds the jets. The diameterof the hole is measured in thousadths of an inch. Typically on the order of like 0.015 of an inch or so if I remember right.

If you cannot warm the whole machine, you should be able sneak just the carb into the house without your wife finding out.

- Rick

 

[keeney]

I did have an old snowblower once that had a bad cowling on it that let enough snow find its way in to plug the carb air intake completely, but that was a strange case.

 

[lyle425]

I suppose I could just take carb off and bring it (not tractor) into the house - that ought to thaw out any ice in the jets, yes?

 

[Treemonkey1000]

Or borrow her hair drier. Just make sure there isn't any raw gas left around the carb and fuel lines. Or a frozen carb will be the last of your worries.

 

[lyle425]

Ahh - Yes, Rick, I think we were having the same thought at the same time there. Also, I noticed that when I took carb apart earlier this eve I broke gasket -- so that will need to be fixed -- gas is now leaking out of bottom of carb -- Aargh!