Bobcat 743 - Wont turn over

[motochriso]

Hi All, New bobcat owner here. Picked up a complete non-running bobcat 743 for $2k and I would like to get it running. Previous owner didn't want to mess with this and went out and bought a new one. I am hoping there is nothing major wrong. The motor will not turn over. I hear a click in the relay but the starter doesn't spin. I pulled the started and turned the key and the starter does engage and work so I fell like the engine is locked up and its not necessarily a starter issue? Does someone have an order of operations they would do? or a thread to start with? I am not all that familiar with the Kubota V1702 engine. I sincerely appreciate all the help. Thanks!

 

[walio123]

Try to drive the engine with a wrench on the crankshaft pulley or with pry bar on the flywheel teeth. If it's not turning it's bad ... you have to disassemble it for diagnosis. If it turns, with not very heavy load it is posiblle starter issue.

 

[motochriso]

Try to drive the engine with a wrench on the crankshaft pulley or with pry bar on the flywheel teeth. If it's not turning it's bad ... you have to disassemble it for diagnosis. If it turns, with not very heavy load it is posiblle starter issue.

Hey Walio - turned over by hand with no issue, everything seemed normal in that regard

 

[walio123]

Try to drive the engine with a wrench on the crankshaft pulley or with pry bar on the flywheel teeth. If it's not turning it's bad ... you have to disassemble it for diagnosis. If it turns, with not very heavy load it is posiblle starter issue.

As soon as it rotates by hand, you have an electric problem. There is another possibility - look at the teeth of the electric motor and those of the flywheel - are good or injured, if they are hurt, it is likely that the solenoid of the starter can not throw away the teeth of the starter. If there everything is ok, you should check the battery, the wires to the starter for loose connections. It is possible that the starter is damaged and rotated without load, and under load can not. Does the gear advance when the starter rotates?Read this http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=105928. Tazza has uploaded pictures, there's a lot written about your problem.

 

[flyerdan]

As soon as it rotates by hand, you have an electric problem. There is another possibility - look at the teeth of the electric motor and those of the flywheel - are good or injured, if they are hurt, it is likely that the solenoid of the starter can not throw away the teeth of the starter. If there everything is ok, you should check the battery, the wires to the starter for loose connections. It is possible that the starter is damaged and rotated without load, and under load can not. Does the gear advance when the starter rotates?Read this http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=105928. Tazza has uploaded pictures, there's a lot written about your problem.

I had this issue with a forklift, starter would just click. Pulled it and it would bench test fine all day.
Turns out the solenoid was wore down (there are two square head copper bolts that make the battery cable circuit) and wasn't letting full power through under load. Burnished everything up, turned the bolt heads so the un-eroded half would make contact with the solenoid disc and it works like new.
Pull the engine through a few rotations to make sure it's free, clean all battery connections and check the solenoid. Chances are it's a free fix on this one, with any luck.

 

[nwilson]

I had this issue with a forklift, starter would just click. Pulled it and it would bench test fine all day.
Turns out the solenoid was wore down (there are two square head copper bolts that make the battery cable circuit) and wasn't letting full power through under load. Burnished everything up, turned the bolt heads so the un-eroded half would make contact with the solenoid disc and it works like new.
Pull the engine through a few rotations to make sure it's free, clean all battery connections and check the solenoid. Chances are it's a free fix on this one, with any luck.

Be sure to clean (sand and/or wirebrush) the lugs on both ends of the battery ground wire as a weak ground can keep the starter from spinning though the solenoid still clicks

 

[motochriso]

Be sure to clean (sand and/or wirebrush) the lugs on both ends of the battery ground wire as a weak ground can keep the starter from spinning though the solenoid still clicks

Well I'm pretty sure this will be a bit of 2 steps forward one step back. Got all the connections and cables clean, bought a fresh battery and tried to start again. Now the starter works motor turns over and it almost sounded like it was going to start then it stopped and wouldn't turn over. Pulled the oil dipstick and what looks like oil/diesel mixture came running out. So I'm wondering if it has an injector or fuel pump issue? Just not sure how so much fuel can get into the oil pan that quick unless rings are bad, so I probably need to do a compression test as well???Any thoughts?

 

[Pizat]

Well I'm pretty sure this will be a bit of 2 steps forward one step back. Got all the connections and cables clean, bought a fresh battery and tried to start again. Now the starter works motor turns over and it almost sounded like it was going to start then it stopped and wouldn't turn over. Pulled the oil dipstick and what looks like oil/diesel mixture came running out. So I'm wondering if it has an injector or fuel pump issue? Just not sure how so much fuel can get into the oil pan that quick unless rings are bad, so I probably need to do a compression test as well???Any thoughts?

Confirm glow plugs are getting power on the rear? It starts on the far back plug and is in series to the front.

 

[walio123]

Confirm glow plugs are getting power on the rear? It starts on the far back plug and is in series to the front.

Check lifting pump, t can cause a rapid rise in oil level/ fuel in the oil/. Remove it without removing the hoses to it and push primer bulb. If there is fuel leak tru lift pump plunger , replase it. If there no leak, check injectors.Do not try to turn the starter until you find out the cause of the fuel in the oil. At a high level, you may cause a hydraulic stroke in a cylinder, which will damage the engine badly.

 

[Tazza]

Check lifting pump, t can cause a rapid rise in oil level/ fuel in the oil/. Remove it without removing the hoses to it and push primer bulb. If there is fuel leak tru lift pump plunger , replase it. If there no leak, check injectors.Do not try to turn the starter until you find out the cause of the fuel in the oil. At a high level, you may cause a hydraulic stroke in a cylinder, which will damage the engine badly.

Glad you got it spinning.
A bad lift pump can indeed let fuel into the engine without knowing it. Were you getting white smoke out the exhaust when cranking?
If it has sit for a while, it's possible injector nozzles are stuck too, you can generally free them your self.

 

[motochriso]

Glad you got it spinning.
A bad lift pump can indeed let fuel into the engine without knowing it. Were you getting white smoke out the exhaust when cranking?
If it has sit for a while, it's possible injector nozzles are stuck too, you can generally free them your self.

Well made a lot more progress on this, turned out it was not fuel coming out of the oil dipstick but a mixture of coolant and oil. Cylinders full of coolant caused hydraulic lock. Pulled the head off and gasket was completely blown between cylinders. Ordered new gasket and going to take the head to the shop to make sure it's not cracked. I ordered a new thermostat, water pump, injectors and gaskets. Hopefully problem will be solved! Cylinder walls looked great so not going to tear it all apart for now.

 

[flyerdan]

Well made a lot more progress on this, turned out it was not fuel coming out of the oil dipstick but a mixture of coolant and oil. Cylinders full of coolant caused hydraulic lock. Pulled the head off and gasket was completely blown between cylinders. Ordered new gasket and going to take the head to the shop to make sure it's not cracked. I ordered a new thermostat, water pump, injectors and gaskets. Hopefully problem will be solved! Cylinder walls looked great so not going to tear it all apart for now.

If you haven't already, turn the engine so the pistons are about mid bore and pool in some Marvel oil to work down into the rings and displace any coolant that might gum things up later.

 

[Tazza]

If you haven't already, turn the engine so the pistons are about mid bore and pool in some Marvel oil to work down into the rings and displace any coolant that might gum things up later.

As you are this deep into the engine, i personally would pull the pistons and hone the bores and re-ring the pistons. You already need a new head gasket, so rather than replacing it again if you find that any rings are stuck once you get the head back on, you need another gasket...
As you mention you had hydro-lock, it may be an idea to check the height of each piston to the top of the block to ensure no rods were bent.