'09 Cub cadet LTX1040 - won't start-

[motoracerx]

I've been posting in this thread, http://www.tractorbynet.com/forums/cub-cadet-l-g/338880-ltx-1040-wont-run.html, but figured I'd start my own.

I bought the mower knowing that it didn't start. I was told that they mowed the grass last friday, shut it off and attached the hose to the mower deck to clean it, then tried to start mower and nothing but a single backfire. Motor cranks but does not fire.

- There is spark
- No OEM fuel pump on this sv590-0220 19 HP Kohler, so there is no 'bad' fuel pump to contend with
- Good fuel flow from inline filter to carburetor
- New spark plug and correctly gapped at .030
- Clean air filter/breather assembly
- Removed and thoroughly cleaned carb with carb cleaner and compressed air
- Installed new carb solenoid repair kit from dealer
- New carb solenoid was tested by connecting the electrical connectors and the plunger engages/disengages with the key off and on
- I have 12 v going to the carb solenoid connector
- Battery is new and strong and I keep it charged after a series of 'cranking'.
- Fresh gas, 3/4 tank.
- Oil level is good

-If i throw some gas into the carb so that it gets into the cylinder, it will make one big backfire and that's it. Same goes for a shot of carb cleaner into the carb/cylinder.

One other point, apparently I have a fixed main jet and needle carb. However, the needle isnt seated squarely. Is that an issue? Here's a pic of the bottom of the needle, looking up through the bottom of the carb.


Any other thoughts, suggestions?
I feel I've covered everything except for some internal problem.

I have a compression tester but it doesn't fit the Kohler engine. Guess I could go buy one to check the compression.

 

[motoracerx]

....and, getting no fuel to the tip of the spark plug??? wth

 

[motoracerx]

0 psi compression

 

[motoracerx]

Took the valve cover off....the rocker arm on the EX side practically fell off the valve spring and push rod.

When I turn the motor by hand and the valve opens or closes, the rocker will become tight again.

The IN side doesn't have any looseness or play.

Did something break on the other end...?

 

[amaxwell]

Is there a cover over the valves to remove, so you can check to see if they are opening and closing properly. The backfire could have bent or broke one . Both valves open = no compression. Another possibility is a hole blown in a piston. (hopefully not).

 

[motoracerx]

Is there a cover over the valves to remove, so you can check to see if they are opening and closing properly. The backfire could have bent or broke one . Both valves open = no compression. Another possibility is a hole blown in a piston. (hopefully not).

Yes, I took valve cover a bit ago....EX rocker arm literally falls off the push rod and valve spring. Here's the pic.

When I turn the motor by hand, the EX valve isn't pushing outward. It retracts a bit and then extends just a bit...maybe broken valve spring.

IN valve is right at spec @TDC.

 

[amaxwell]

Is the push rod broken or bent ? It should be as tight as the other one.

 

[motoracerx]

Is the push rod broken or bent ? It should be as tight as the other one.

Nope. Push rod is fine. EX Valve is in tact as far as I can tell by looking through the EX port. Research and a youtube video is telling me it could be the valve guide on the EX side. Apparently when the engine gets hot or too hot, the valve guide can come loose and shimmies up the valve. Something is definitely wrong with the valvetrain.

I put the mower back together and been researching all dam n day.

Gawd, I didn't know these Kohler courage engines are the worst ever made...that's the consensus anyway. Can't find one positive review about them.

 

[Bob_Bainbridge]

The "bad" valve looks to be lower in height than the good one. Is that normal? If not it would indicate a stuck/bent exhaust valve which could also indicate piston damage.

Bob B.

 

[oldpilgrim]

broken valve spring ? Something stuck in the chamber, holding the valve open?

 

[motoracerx]

broken valve spring ? Something stuck in the chamber, holding the valve open?

Winner winner chicken dinner! Took the head off today this is what I found. Piston looks fine.

Before I took the head off today, I found a 20HP Kohler courage local to me....Rod broke and came out of the cases. After researching part numbers, it checked out that the 20HP and 19HP Kohler Courage engines are the same as far as I could tell....Only thing I could find is that the 20 had a fuel pump. The 20 came off a LT 1045, mine is a LTX 1040.

So for $50, I got the complete motor...starter, carb, exhaust, etc...

Pulled the head off the 20HP Kohler, and it looks great, piston is good, no apparent PTV contact issues (piston to valve).

The head/cylinder gasket and valve cover gasket looks good...I want to re-use them but I guess I'll buy new and make it right. I already have new exhaust and carb gaskets from the carb solenoid repair kit I already put on the 19HP.

 

[oldpilgrim]

That doesn't happen very often. I would think that it overheated to allow the steel seat to come out of the aluminum head.

glad you got out of it cheap.

 

[motoracerx]

That doesn't happen very often. I would think that it overheated to allow the steel seat to come out of the aluminum head.

glad you got out of it cheap.

UPDATE.....I put the new/used head on, new gaskets, studs, torgued properly, etc....

It was a 'hard' 1st crank when it turned over, but it fired right up and sounded good.

BUT, the oil light is on. Yes, it has fresh oil and to the full line.

I thought maybe I should run it for 20-30 secs to get the oil circulating throughout the engine, and maybe the light would go off....so I did just that, ran it for less than 30 secs but the light stayed on. I shut it off in case I do have an 'oiling' problem.

Any thoughts, ideas?

pilgrim-Concerning your overheating suggestion with the valve seat popping out, could the original problem possibly have been an oiling issue that caused the engine to overheat to begin with?

I guess I'll start researching 'engine oil light'.

 

[motoracerx]

When i turn the key on, oil light is on and the display shows 'change oil'....I read that that is a change oil warning light and will stay on for 5 days and then doesn't reset for 2 hrs after you change the oil...

Anyway, took it for 1/2 lap around my yard, less than a minute, and it started to struuggle/lose power, I shut it off.

Oil pump out of it? Oil sending unit, if there is one? Stop now and sell it as is or for parts? lol

 

[oldpilgrim]

pilgrim-Concerning your overheating suggestion with the valve seat popping out, could the original problem possibly have been an oiling issue that caused the engine to overheat to begin with?

I would think it possible, but if it overheated sufficiently to do that, then I think there would be other issues as well, like bearings.

It could have just been a mfg issue where the seat wasn't seated, pressed or machined properly. But based on this:

When i turn the key on, oil light is on and the display shows 'change oil'....I read that that is a change oil warning light and will stay on for 5 days and then doesn't reset for 2 hrs after you change the oil...

Anyway, took it for 1/2 lap around my yard, less than a minute, and it started to struuggle/lose power, I shut it off.

Oil pump out of it? Oil sending unit, if there is one? Stop now and sell it as is or for parts? lol

I'd bet on heat. If it started to lose power, that's a sign of over heating or under lubrication causing the overheating. I'm not familiar with the oiling procedures built into that engine, or if it even has an oil pump, it probably does, but it sounds like a pump problem to me.

 

[Bob_Bainbridge]

Never, never reuse a head gasket. Glad you got new ones.

Bob B.

 

[motoracerx]

Never, never reuse a head gasket. Glad you got new ones.

Bob B.

RIght on. I knew this, but was just anxious to have it running at that point. I would have replaced the gasket once they came in.

I'm going to go ahead and check the valves again...., compression test just to see where I'm at.....an then pull the closure plate to see what I can see.

 

[motoracerx]

Well, I pulled the spark plug and it was black as could be....
Compression test and it cranked over twice to about 100, and then it didn't want to crank. Battery is new.
So I pulled the valve cover and the EX valve was very loose.

Motor cranks freely when plug is out. I read this http://www.tractorforum.com/f284/cub-cadet-ltx1040-starting-issue-17532/ , so I decided to pull the closure plate to see if the hard crnaking was caused by a faulty compression release, ACR.

Everything looks good. Cam gears, the ACR (compression release) mechanism is in place. Oil nice and clean. No gas smell in oil. No metal shavings. Flywheel key and upper crank gear key in tact, etc....

I visually can't see a problem.

I wonder if the EX valve being out of adjustment, caused the plug to misfire hence the motor losing power? Maybe i should have just readjusted the valve, put a new plug in it, and see what happened?

What else can I check for while the crankcase is open? I'm not going to take the crank out and check tolerances and such. I'm not getting that involved with it...I don't have the time or the desire.

 

[oldpilgrim]

I wonder if the EX valve being out of adjustment, caused the plug to misfire hence the motor losing power? Maybe i should have just readjusted the valve, put a new plug in it, and see what happened?

I suppose the EX valve could not be closing all the way and when the engine gets hot, the valve grows longer and compression gets worse, thereby slowing down.

But you say it was loose, so that would mean it's not opening all the way which would indicate that as it warms, gets longer so that it would be more in spec as it heats.

Did you actually look at the EX valve seat and mating valve surface? When you said it was loose, did you check it when you are at TDC when both valves are closed on the compression stroke?

100lbs compression is good. I'm guessing you didn't check it when it was shut down after it lost power?

 

[motoracerx]

When I said the EX valve was loose, I mean 2mm worth of looseness. I paid extra attention making sure that the pushrods were seated in the cam levers and TDC when I adjusted the valves upon install of the head....the only thing I may not have done was having TDC on the compression stroke. I thouught I was 100% certain that i was TDC with both valves closed on the compression stroke? I rotated the crank several times making sure I was TDC every which way possible, so I thought. I'll double check this time arouund.

Yes I inspected the valve seats and mating surfaces. Looked good. Valve guides also appear to be at proper depth.

Like I said, it was a hard couple cranks when it fired up, but sounded good and mowed great for a minute, then loss of power and subsequent fouled plug and loose EX valve.

Getting ready to put the closure plate back on, and give it another go.

Thanks for the feedback.