No compression on 108

[Dustin Wilson]

Hi all,

The 108 I am picking up tomorrow doesn’t run. Any guesses as to what I should try first based on the following fb marketplace listing for it?

Cub Cadet 108 garden tractor. This tractor is not running and I did not have it running. The engine spins free and the piston is moving but does not have compression.

Thanks!

 

[gary noblit]

If it were me ,I'd first pull the head to check for stuck valve, or hole in a piston..I would also try my own comp. test first....My first clue is "piston is moving"..How would he know that???

 

[Dustin Wilson]

Thanks. This is all new to me.

 

[bwstevens]

I'm a guy who would crank the thing and listen to the exhaust and intake to see if there is any air movement.

 

[hydroharry]

Unless the PO removed the head how would he know the piston is moving (I guess he could remove the breather/valve cover and possibly see it moving thru the little breather hole into the bore). I would NOT start by throwing a battery on it and trying to start it. It might just cause more damage.

My guess is the PO was able to rotate the crankshaft and just claimed piston is moving rather than saying crank turns freely.

1st thing I'd do is rotate the crank. If it turns really freely then you know it's a broken rod. Next step would be to remove the head and have a look see if the piston is there or broken into pieces.

If crank turns somewhat freely then seems to build compression and gets harder to turn then the piston and rod may be intact and you could attempt to start with a battery.

If you rotate the crank and it just stops and some point and locks up then it's likely a broken rod or piston and those parts are jamming the rod or crank from rotating. Do NOT hook to a battery to attempt starting. It might cause further damage. I'd remove head and have a look see.

 

[charles germer]

another vote for removing the head first, IMMO there's a good chance a valve is stuck from sitting for who knows how long

 

[PACub100]

Me 3... remove the head.
Gasket is cheap and while you're in there, if it turns out nothing is wrong, you wiggle the piston to get an idea on rings, clean and check the head and valves...

 

[mfrade]

Basics for me would be see if the crankshaft turns. Just feel if it makes compression. If it does, then pull the spark plug and inspect for cleanliness and gap, spray/ squirt some lube into the cylinder, connect the spark plug to the wire and ground the threaded portion, crank it and see if it sparks. If it doesn't, inspect / clean /gap points. Re-check for spark, if it does then verify cleanliness of gas tank. If clean and use-able, add gas. Set choke and add some throttle, crank it and let it fire up. If it runs - great. See if it will idle. Will it move on it's own power? Shut it down and let it cool. Use the test run / evaluation to decide how much you need to do. Pull the head for cylinder inspection & de-carbon cleanup. Make a parts list and have fun!

 

[dschwandt]

All this and more.....IF the seller will allow you to do that!!

 

[1811Cub]

All this and more.....IF the seller will allow you to do that!!

Sounds like he already bought it and is bringing it home

 

[mgwin]

Even though all the suggestions are very good, it would be impractical to perform most of these in someone's yard that you do not know. You could be there all day! I also doubt he would let you take his tractor all apart.
I would suggest to look at the tractor and see what kind of condition it is in overall. Yes, you could turn the crank to see if there was any compression. Any oil leaks will be obvious. Basically that would be about all you could do without spending the day with a stranger.
I would bet the owner just wants to sell it and get it gone within an hour. You would just have to determine if it suited your needs for the price he wants. More than likely they will come down some on the price, you will just have to negotiate.
After you get it home, you can do anything you want. You will just have to decide if it is worth it just by looking at it.

 

[mfrade]

Hi all,

The 108 I am picking up tomorrow doesn’t run. Any guesses as to what I should try first based on the following fb marketplace listing for it?

Sounds to me that he's already bought it!

 

[hydroharry]

Even though all the suggestions are very good, it would be impractical to perform most of these in someone's yard that you do not know. You could be there all day! I also doubt he would let you take his tractor all apart.
I would suggest to look at the tractor and see what kind of condition it is in overall. Yes, you could turn the crank to see if there was any compression. Any oil leaks will be obvious. Basically that would be about all you could do without spending the day with a stranger.
I would bet the owner just wants to sell it and get it gone within an hour. You would just have to determine if it suited your needs for the price he wants. More than likely they will come down some on the price, you will just have to negotiate.
After you get it home, you can do anything you want. You will just have to decide if it is worth it just by looking at it.

Ya, I agree Marty if he hadn't bought it already. Other thing I like to do is have a good look see around the S/G mount section of the block for any windows or cracks.

As for the price, agree with that to. Only ever went to look at one where the guy actually raised the price after I had the look see and probably did a little to much checking and making it run a little better. Kind of a smart a_ _ if ya know what I mean, but ended up agreeing to the original asking price. Always have to be aware that if you happen to unintentionally fix something for somebody it might cost you.

 

[mgwin]

That's why I say: "buy it first, take it home, then tinker with it!"
A guy tried that with me once, when I bought a Brinly planter. It was the first thing we looked at, and he said it was $100. I said I will take it. After looking at all his other stuff, we added up the cost. He then said the planter was $200. I told him "you said $100 for it." He said if he told me $100, he would let me have it for that. Long story short, I made two trips to get all the stuff!

 

[Dustin Wilson]

Thanks much for the suggestions! I bought it for $100. Hopefully, with your suggestions I can get her running.

 

[mgwin]

I know you can.

 

[Dustin Wilson]

another vote for removing the head first, IMMO there's a good chance a valve is stuck from sitting for who knows how long

The PO said it sat for nearly 15 years, hopefully that's all it is.

 

[hydroharry]

Gol dern it, just remove the head and see if you have a stuck valve or whatever is going on. I really doubt it just sat for 15 years for no reason. And besides, Kohler recommends decarboning the head and piston ever 500 hours of use. Who knows if it was ever done. Replacing the head gasket is pretty cheap to get a look at what you really have. (Make sure you get an OEM Kohler gasket to - some of the aftermarket ones have been known to fail almost immediately). And if you have a broken piston or hole in it, or a broken rod you can just throw the old gasket back on until you decide what you're gonna do.

 

[RayF]

Surely, I cannot be the only one on here that knows the K241 engine has a "compression release" system during cranking.... The engine does NOT build any real pressure at slow cranking speeds (by hand)... though you CAN feel a slight push/pull of air circulation.... IF you can spin it fast enough.
No need to remove the head just yet. I would get her home, remove spark plug, put in an oz of Marvel Mystery Oil, crank it over by hand a few times (while checking for spark)... shoot some ether down the carb and see if you have any fire at all....
Share the results and we'll take it from there.

 

[hydroharry]

Surely, I cannot be the only one on here that knows the K241 engine has a "compression release" system during cranking.... The engine does NOT build any real pressure at slow cranking speeds (by hand)... though you CAN feel a slight push/pull of air circulation.... IF you can spin it fast enough.
No need to remove the head just yet. I would get her home, remove spark plug, put in an oz of Marvel Mystery Oil, crank it over by hand a few times (while checking for spark)... shoot some ether down the carb and see if you have any fire at all....
Share the results and we'll take it from there.

Ray - that slight push pull of air is compression. If you ever spun one with a broken rod you would know the difference. Sometimes they turn so free they will keep on going after you release your hand.

Far as I can tell Dustin hasn't told us anything yet except the PO saying it has no compression but the piston moves. If it does in fact have slight compression upon rotation by hand, then yes I basically agree with you and he should attempt starting.

But if it just spins freely I'd still remove the head for a look see.

Dustin - what's your true evaluation of the compression now that you have it home??? We're all tired of waiting and will soon loose interest and you'll be buying your wife a new pair of shoes with the proceeds from the 108.