782 cub cadet ignition or carb problem

[Sparky]

The thing about it only doing it pulling the sled makes me think of possibly an air restriction kind of like when the rubber air intake collapses shut on a 1066 and black smokes when pulling the field cultivator......probably way off here, I know, big difference between gas and diesel....just throwing it out there as something to check.

Travis

[MinnesotaFarmall]

3 hours ago, 560Dennis said:

Do you have kill switch ?

No I do not besides the key.

[MinnesotaFarmall]

2 hours ago, Sparky said:

The thing about it only doing it pulling the sled makes me think of possibly an air restriction kind of like when the rubber air intake collapses shut on a 1066 and black smokes when pulling the field cultivator......probably way off here, I know, big difference between gas and diesel....just throwing it out there as something to check.

Travis

That's about the only thing I can think of too besides the condenser.

[snoshoe]

Have already said check valve lash 3 times this makes 4. I am almost positive an exhaust valve is sticking. Even if lash is good doesn't mean they are not sticking but to tight will make them do it. OK I'll shut up now.

[HydroTek]

9 minutes ago, snoshoe said:

Have already said check valve lash 3 times this makes 4. I am almost positive an exhaust valve is sticking. Even if lash is good doesn't mean they are not sticking but to tight will make them do it. OK I'll shut up now.

Can lead a horse to water ...

[560Dennis]

8 hours ago, MinnesotaFarmall said:

No I do not besides the key.

Wow , ok ✅ 

does the front of the tractor lift off the ground ?

Does your daughter wear a dot helmet pulling ?

[Binderoid]

11 hours ago, snoshoe said:

Have already said check valve lash 3 times this makes 4. I am almost positive an exhaust valve is sticking. Even if lash is good doesn't mean they are not sticking but to tight will make them do it. OK I'll shut up now.

Well i don't  have an answer,  just wondering  why valve lash was only  a problem  when  hooked  to the sled. 

He said elsewhere that it was at max load or something during  it's other duties and never  missed a beat. 

But yes by all means,  eliminate the  valves  as the source of the trouble, we got nothing  else to go on. Definitely  a showing problem  for sure. 

[HydroTek]

Could be lash if the extra heat is making the valve longer and holding it open some
-- but more likely valve sticking from carbon can be the issue 

Mowing a lawn rarely puts the engine under much of a load
-- unless that "lawn" is like my neighbors -- then more like a hay field

Hole in the muffler -- blowing hot exhaust back on the carb or intake 

[Binderoid]

He did say mows the grass " as tall as the hood" which led me to believe there was substantial load on it.

Maybe it needs "every last hp" to pull the sled because of all the fuel dumping in, not necessarily  because  of the sled itself.

I feel like some crucial detail  is being omitted,  or a couple  strange coincidences  are occurring. 

[MinnesotaFarmall]

14 hours ago, 560Dennis said:

Wow , ok ✅ 

does the front of the tractor lift off the ground ?

Does your daughter wear a dot helmet pulling ?

No wheelies, off the lawn class so never makes enough traction yet. And yes dot helmet. Blue and silver in colour. 

[MinnesotaFarmall]

22 hours ago, snoshoe said:

Have already said check valve lash 3 times this makes 4. I am almost positive an exhaust valve is sticking. Even if lash is good doesn't mean they are not sticking but to tight will make them do it. OK I'll shut up now.

Not that I don't believe you, but tell me why it won't do it during normal operation like mowing the lawn and such?

 

And I've heard you in the back row yelling. Just haven't gotten there yet. Thank you.

[MinnesotaFarmall]

4 hours ago, Binderoid said:

He did say mows the grass " as tall as the hood" which led me to believe there was substantial load on it.

Maybe it needs "every last hp" to pull the sled because of all the fuel dumping in, not necessarily  because  of the sled itself.

I feel like some crucial detail  is being omitted,  or a couple  strange coincidences  are occurring. 

Can't think of anything else because this is the only thing that makes it do it. I've been through the carburetor enough to do it with my eyes closed, every jet, air vent, bleed, and seal is good and clean, in good shape. The fuel pump pumps a tremendous amount of fuel. Three or four seconds of cranking and there is almost an inch or so of fuel in a pop bottle. Good fresh fuel, she drives it all over the lawn no problems it always fires up and runs awesome. It only does it when hooked to the sled.

[MinnesotaFarmall]

22 hours ago, HydroTek said:

Can lead a horse to water ...

Maybe your hat makes the water smell funny?

[snoshoe]

48 minutes ago, MinnesotaFarmall said:

but tell me why it won't do it during normal operation

Not steady full throttle

[MinnesotaFarmall]

43 minutes ago, snoshoe said:

Not steady full throttle

So unless I'm not quite understanding that running the mower deck with the lawn mower wide open throttle doesn't make the valves stick?

[snoshoe]

20 minutes ago, MinnesotaFarmall said:

So unless I'm not quite understanding that running the mower deck with the lawn mower wide open throttle doesn't make the valves stick?

Carb throttle is not wide open until engine is loaded to full load.

[560Dennis]

Well+from the good comments .

I got this thought .

only does it at pulling correct. 👍🏻 

then how do we duplicate that at the shop to correct it. 
black smoke pulling ,is to much fuel .only thing I can think of is the Governor is pulling the carburetor butterfly to wide open . Correct , how is that giving it to much fuel .how is that possible and how that would happen .

id back off the float height to get less fuel to and accurate measurements . 
well done ,  silver and black helmet ⛑️ 

[Binderoid]

11 hours ago, MinnesotaFarmall said:

Can't think of anything else because this is the only thing that makes it do it. I've been through the carburetor enough to do it with my eyes closed, every jet, air vent, bleed, and seal is good and clean, in good shape. The fuel pump pumps a tremendous amount of fuel. Three or four seconds of cranking and there is almost an inch or so of fuel in a pop bottle. Good fresh fuel, she drives it all over the lawn no problems it always fires up and runs awesome. It only does it when hooked to the sled.

I hate it when simple devices make you pull your hair out. Got  a  Honda Foreman carb under my skin right now.  

A non-technical  friend  once told me sometimes you just gotta put a different  pair of eyes on it... you probably  saw the problem  a dozen  times and it never registered.

[HydroTek]

2 hours ago, Binderoid said:

Got  a  Honda Foreman carb under my skin right now.  

Check the "choke" valve on that carb 
-- the little rubber tip seal dry rots and cracks 
-- other issue is low fuel flow from the tank valve 

[Binderoid]

1 hour ago, HydroTek said:

Check the "choke" valve on that carb 
-- the little rubber tip seal dry rots and cracks 
-- other issue is low fuel flow from the tank valve 

The fuel tap has been serviced, new fuel line, new start valve w/cable, and every piece inside that can be unscrewed is new (slide diaphragm too). No dirt, gum or water in the carb when I took it apart.  

Runs fine anywhere above idle. But set the idle too high and you can't shift it. Low idle it just pops back through through the carb and quits, unless you keep the choke valve cracked.

Had been testing it without the airbox, then was told that entire intake assembly has to be installed because they are so touchy. No go on that one. 

Ran it up on TDC and checked the timing marks,  hoping for sheared flywheel key. Every thing right on the money.  All ignition components are new with the exception of the pulse coil,  which would mean pulling the engine.  

Apologies for hijacking your thread, Minnesota, I just got excited talking to someone who knows anything about these machines. 

 

[HydroTek]

48 minutes ago, Binderoid said:

The fuel tap has been serviced, new fuel line, new start valve w/cable, and every piece inside that can be unscrewed is new (slide diaphragm too). No dirt, gum or water in the carb when I took it apart.  

Runs fine anywhere above idle. But set the idle too high and you can't shift it. Low idle it just pops back through through the carb and quits, unless you keep the choke valve cracked.

Had been testing it without the airbox, then was told that entire intake assembly has to be installed because they are so touchy. No go on that one. 

Ran it up on TDC and checked the timing marks,  hoping for sheared flywheel key. Every thing right on the money.  All ignition components are new with the exception of the pulse coil,  which would mean pulling the engine.  

Apologies for hijacking your thread, Minnesota, I just got excited talking to someone who knows anything about these machines. 

 

Yeah, carb needs the air system intact to get the engine to idle correctly -- it is a pain for sure 
-- you have the 90 degree screw driver to set the idle mixture ?

Been a while since I have had mine apart -- is there an adjustment on the slide needle ? 
I have 2 of those Ranchers on my Farm -- only the one has gave any problems , and I think it was mostly from dirt in the fuel. Had to replace the tank valve because the rubber "swelled up" and blocked the fuel ports.  Replaced the "choke valve" because the rubber seat had cracks in it . Cable once also , end pulled off the plastic

Both of these machines have a mostly "easy" life here spraying fence rows and working cattle 
-- I run a gallon of aviation gas in the tank -- seems to make the engine idle much better than just plain fuel 

[MinnesotaFarmall]

8 hours ago, 560Dennis said:

Well+from the good comments .

I got this thought .

only does it at pulling correct. 👍🏻 

then how do we duplicate that at the shop to correct it. 
black smoke pulling ,is to much fuel .only thing I can think of is the Governor is pulling the carburetor butterfly to wide open . Correct , how is that giving it to much fuel .how is that possible and how that would happen .

id back off the float height to get less fuel to and accurate measurements . 
well done ,  silver and black helmet ⛑️ 

Thanks, the only other thing I can think of is literally the simplest thing, the air filter. Could possibly be that it just can't keep up. Tomorrow of all goes well with the rain, I'll pull the filter out to see if that helps.

[560Dennis]

I just thought this might help you out . I use to use  the advice ,when I was active pulling 25+ years ago .

https://gardentractorpullingtips.com/carbfuel.htm

[MinnesotaFarmall]

Well we went to the pull again after triple checking carb and points. It fell on its face puking black smoke out again. Next step is to check tappet clearance. Pulling the air filter also made no noticable difference.

[HydroTek]

45 minutes ago, MinnesotaFarmall said:

Well we went to the pull again after triple checking carb and points. It fell on its face puking black smoke out again. Next step is to check tappet clearance. Pulling the air filter also made no noticable difference.

Sounds like you need to hook to something at home and figure this out 

-- you for sure there is no hole in the muffler ?