1250 Coming to a crawl / stalling out under load

[martyrant]

Originally Posted by DeltaCub

http://www.onlycubcadets.net/forum/s...ead.php?t=4630

Engine cradle modification link.

Thank you, that's rather simple. Is there a significant improvement? I would assume so as it's structural.

[DeltaCub]

Originally Posted by martyrant

Thank you, that's rather simple. Is there a significant improvement? I would assume so as it's structural.

To answer your question yes. The oil pan mounting bosses are not damaged because of loose and/or missing mounting bolts. The engine will stay anchored resulting in less wear and tear on the driveline too. This, of course, depends on the mounts being installed properly.

[DeltaCub]

Originally Posted by martyrant

Thank you, spent some time today tinkering and things were going pretty well for a little over an hour of use after I printed section 6 of that manual and followed the instructions for setting the needles.

I didn't clean the carb, and due to the instructions saying to put a load on the motor while adjusting the needle in step 4 there, I changed over to the rototiller and turned on the PTO while I set that.

I had the tiller on so why not do the garden since the wife was asking me about it and that was one of the reasons I started looking at this again. Was able to till the thing and was doing one last clean pass along some grass, ran it to the end and the ground turns pretty hard/rocky (it's where I haven't tilled in past years) so the thing just stalled and turned off rather abruptly. Figured that was a sign that I was done for the day and started up the hill with the PTO off, half speed, and the thing just stalled abruptly again.

Figured at this point something serious was probably wrong so I wanted to leave it but it was on a hill and rather than just let it drift back down I started it again and got it to the top and shut it off.

It was not acting like before where it would get all sluggish (struggling) and stall though, both times it just abruptly turned off -- not sure if it's an overheating issue now?

They are just small wisps of white smoke, so I'll take it that is normal.

(Yes I know I should have a belt cover on the tiller)

You may want to remove the carb to clean and inspect it...Check your fuel tank for crud and debris too. You may have some debris that could be restricting fuel flow. Does the engine seem to run hotter than normal? If yes you need to address that issue. Causes for overheating...1) Lean fuel mixture, 2) Incorrect ignition timing, 3) Fins around block are cluttered with debris or rodent's nest, 4) Exhaust valve sticking. If one or any these conditions exist you will damage the engine. Some care and maintenance will help long term.

[Randy Littrell]

I think you need to go back and give us all the details as to what was done to the motor and if you or someone else did the work. You mentioned rebuild but then said just gaskets and such.

The choke needing to be partially closed could be the throttle shaft worn and sucking air causing it to run lean. Search throttle shaft bushing and you will see what you need there.

I am sure someone with more smarts than me about these motors will come along soon.




Randy

[martyrant]

Originally Posted by Randy Littrell

I think you need to go back and give us all the details as to what was done to the motor and if you or someone else did the work. You mentioned rebuild but then said just gaskets and such.

The choke needing to be partially closed could be the throttle shaft worn and sucking air causing it to run lean. Search throttle shaft bushing and you will see what you need there.

I am sure someone with more smarts than me about these motors will come along soon.

Randy

I didn't rebuild it and it's been quite some time, but it was done by someone who had a long time running business of only rebuilding small engines (this wasn't his first k301). He took it completely apart and fixed what needed to be done, but I am not 100% sure what it was as I don't remember the whole conversation with it being about 3 years later and I can't find the invoice at the moment (probably won't, either).

The reason I had brought it to him to be rebuilt in the first place was it was pouring oil. Turned out it was a cracked oil pan. That's why I'm assuming all that was done was gaskets as if I recall correctly he said it was in rather good shape other than the oil pan issue. In retrospect if I had known a lot more about it and inspected the oil pan I wouldn't of needed to rebuild it all.

The exhaust cover was taken off and painted at the time by the gentleman who did the motor as well.

I think with redoing the needles this morning I was able to fix the choke issue (it doesn't have to be half open to run properly at WOT).

[martyrant]

Originally Posted by DeltaCub

You may want to remove the carb to clean and inspect it...Check your fuel tank for crud and debris too. You may have some debris that could be restricting fuel flow. Does the engine seem to run hotter than normal? If yes you need to address that issue. Causes for overheating...1) Lean fuel mixture, 2) Incorrect ignition timing, 3) Fins around block are cluttered with debris or rodent's nest, 4) Exhaust valve sticking. If one or any these conditions exist you will damage the engine. Some care and maintenance will help long term.

I didn't do the carb because I figured I'd at least try the needles and things seemed to be going okay until about after an hour of use, but I'm seeing it repeated so I'll do that tomorrow or Tuesday when I get a chance.

My neighbor does have a john deere from the same year with the k341 and he said that it would quit after a while from overheating and one day it blew a hole in the exhaust and it fixed his overheating issue, so I'm wondering if painting the shroud (something the person who rebuild the motor did, he painted the whole thing with high heat engine paint) or something could be the issue with it shutting off after an hour.

If I have a thermal IR temp sensor, what is a good way to tell if the engine is overheating? Or is there a safe spot to just do a feel test?

I did add a fuel filter before I went to doing anything today too and it is fresh high test gas.

I'll pull the carb and clean/inspect it next.

[twoton]

All good points there from Ms DeltaCub and Randy "to tall" Littrell.

If it's not runnin' good it's time to start with the basics, pull the plug, it'll give you a good indication of how it's runnin'. Clean and or replace.

I think it's a Champion H 10 C or equivalent, gaped to .035".

Fresh fuel and clean fuel system is a must.

Rebuild the carb;

http://www.mgonitzke.net/cubcadet/to...rb_rebuild.pdf

carb rebuild kit (part # 25 757 02-S)

Randy's right about that worn throttle shaft, it'll cause the engine to hunt.

throttle shaft bushing (part # 25-158-02-S)

And what Ms DeltaCub said about engine timing, clean points and properly timed engine.

Get a set of new Points Kohler (part # 47 150 03-S)

And set the timing using the static method;

http://www.mgonitzke.net/cubcadet/to...tic_timing.pdf

Good luck..

[ol'George]

And drain that hi test gas out and use regular unless you are running a hi compression race engine.
and FWIW,
most hi test you purchase is quite old,
I mean just how many ppl purchase it?
Hell it might be a couple of years old.

The only place I know of that it sells an unusual amount of race gas, is the sunoco station across the street from a local asphalt circle track during the racing season.

[johncub7172]

Hey, f.y.i: Those new Cub Cadet ISO engine mounts are different from factory o.e.m mounts. The new mounts assemble and adjust with simplicity and ease, the only major adjustment being how much to tighten down the lock nuts, in my experience.

Also, I read here a while ago, to spray carb cleaner into/onto the throttle shaft and note any engine speed up or slow down.

But for the main topic, I'd guess a condenser starting to give out. To me, if the engine starts over with out a lot of starter cranking, no major back fires, or over heating, and if the points are correctly adjusted, then I would not suspect timing.

Sounds more like a carb issue to me, as in surging.

[twoton]

Originally Posted by johncub7172

...I'd guess a condenser starting to give out....

Good point there by johncub7172.

and... the importance of proper engine block grounding cannot be over stated.