1250 Coming to a crawl / stalling out under load

[J-Mech]

Anyone going to actually tell this guy something he needs to do to try and fix it? Or is everyone just going to post links and their wild guesses?

Why don't you guys give him a list of things to do to diagnose, or fix it.....

[twoton]

Originally Posted by martyrant

I can't remember if it really had this much thrashing/movement to it at idle [I do know the exhaust hood is missing some screws that adds to the drama on the thrashing], but it goes away a bit at higher throttle,.

Worn out, or improperly adjusted ISO mounts can contribute to engine shake as can an engine that is not timed properly.

Originally Posted by martyrant

I noticed it throttling up/down just sitting there,

Improperly adjusted carb and or worn throttle shaft and bushing. Bad fuel. And,..

Re set the Governor. You can find information on this procedure on page 6.29 and 6.30 of the Kohler K series Service manual found here;

http://www.onlycubcadets.net/forum/s...0422#post30422

How's that?

Originally Posted by martyrant

when I'm actually trying to use it (leveling the driveway with the box blade would even stall it after about 15-20 feet)….

Bad fuel, fouled plug, pitted/dirty points, worn/ out of adjustment carb, engine out of time, did I say re set the governor?

Overall sounds like just a lack of proper maintenance. I think we gave him a bunch of useful information to help him diagnose his own problem.

[twoton]

Originally Posted by martyrant

Pretty sure it was just the gaskets / oil pan on the rebuild.

I would also add that the rebuild may not have been adequate..

Sorry martyrant, no offence intended.

[martyrant]

Originally Posted by 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.

I did replace the condenser already -- along with the regulator as well. Both are new.

I'm not experiencing the engine surging anymore. The only issue I'm having after adjusting the needles is that it randomly turned off after an hour of use. I think someone else had a good point that I was running high test gas in there, which of course would make it run hot... (we do get fresh high test around here, I do live next to a raceway so his other point there while valid most places isn't here). I'm going to drain that and try regular gas as well as pull the carb like someone else said.

[martyrant]

Originally Posted by twoton

Worn out, or improperly adjusted ISO mounts can contribute to engine shake as can an engine that is not timed properly.



Improperly adjusted carb and or worn throttle shaft and bushing. Bad fuel. And,..

Re set the Governor;

http://cubfaq.com/govadjust.html



Bad fuel, fouled plug, pitted/dirty points, worn/ out of adjustment carb, engine out of time, did I say re set the governor?

Overall sounds like just a lack of proper maintenance. I think we gave him a bunch of useful information to help him diagnose his own problem.

Thanks twoton, it seemed like adjusting the needles fixed those issues after DeltaCub gave me the manual.

The issue I'm having now is that it turned off after an hour of use abruptly.

[martyrant]

Originally Posted by twoton

I would also add that the rebuild may not have been adequate..

Sorry martyrant, no offence intended.

None taken, if it has to be done again I'll end up doing it myself with my neighbor (who's been rebuilding diesel engines for 50+ years) to make sure it's done right rather than having someone else do it this time.

Just trying to figure out if I can avoid rebuilding it (again) since it seemed to start working a lot better after adjusting those needles other than quitting after an hour of use.

Going to drain the gas like I said in my last post and clean/inspect the carb, I'll check the governor again but it seemed to be sitting ok.

[twoton]

Originally Posted by martyrant

..... it turned off after an hour of use abruptly....

Could be your coil is giving you fair warning...

http://www.onlycubcadets.net/forum/s...707#post343707

[johncub7172]

Originally Posted by twoton

Good point there by johncub7172.

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

Thanks twoton! I have also added an extra engine ground to my 1450, which will ground the engine to start with the starter cable ground removed.

After an hour of run time, and shutting off, could it be carbon deposit? Might need to remove the head, and inspect the situation. If we have an exhaust valve moving slowly, we will loose a certain amount of piston compression, and slow down the 1250 to a crawl. Try a compression test? I recommend to start using Marvel Mystery Oil in the fuel. This stuff will begin to clean up the combustion chamber. Being here since 2009, I have used this stuff off and on and have not ever experienced a slow down in my engines.

Only points of consideration, hopefully we can get some more good ideas on this 1250 scenario.

[Terry C]

I'm not convinced you solved your lean condition (using the choke to keep it running) with some needle adjustments. Need to really clean the carb and the rest of the fuel system. Still too lean and getting hot.
Check the timing using the static method also.

[J-Mech]

I'm sorry.... I should have been more specific. DeltaCub was doing a fine job!


martyrant:

I lost count of the number of time people suggested cleaning the carb (fuel system). I suggest you listen.

Stop saying this engine was rebuilt. Replacing an oil pan and gasket is not a rebuild. Unless you can find proof, or remember what was done, you need to quit saying it was rebuilt. Honestly, I don't know how you could not remember if a motor was just repaired or overhauled. Quite a difference in price. If you didn't pay $700 to $1000 it didn't get overhauled, it got repaired.

I watched your video. Your quite the fool. You held that governor nearly at WOT. Are you trying to blow up your engine??? The engine is governed, and it is only designed to run up to at 3600 RPM. After that, you have to replace key parts to make it run faster. You revved it far over 4000 RPM. Your lucky it didn't fly apart. Keep your dang finger off the throttle unless you know what your doing, or unless you want to see what shrapnel from a cast iron flywheel feels like stuck in your leg. Good grief.


You really just need to do some fuel system cleaning and general maintenance to this thing. Go ask your neighbor to help. Use the service manual. Disassemble and clean the carb AND fuel tank. Replace the fuel line, install fresh gas. Reset the governor, adjust the valves. Replace the spark plug and the plug wire. Tune the carb to run on the motor after installation, not just to "factory specs". The screw positions the book suggests are just for a starting point. The book states that. Set the timing and clean the points. Don't gap them, set the timing. The books tells you how. If your neighbor is a good mechanic, he should know all that though. I think you definitely need some assistance in fixing this.

Go do all that and post back. You've had more than enough "help" to get starting doing something.




twoton:

Do you know how to explain anything on your own? Or do you have to post a link to other sites and other threads to accomplish every explanation you give? Why don't you try actually explaining something without using someone else's information. On another note, you used a cubfaq link to explain how to set and adjust the governor, yet DelaCub gave a link to the Kohler manual AND the OP said he downloaded it! Why not give him a page number or reference the service manual instead of another site? The manual should be the first place anyone looks for information.