743 head

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MWorld

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Purchased a 743 from a man who had done some work at my house some time ago. He came to me the other day and said he needed to sell the machine, he wanted $2000.00 for it....so I gave him $1500.00. He said it had a blown head gasket, but otherwise worked great. I firgured it wasn't such a bad deal, I always liked the machine when he was working at my house, plus I own an auto repair shop.
It has the Kubota V1702 engine.
I took the head off yesterday and found the head was cracked in #2, #3 and #4. The gasket was blown out into #2, but #3 was the cylinder that was soaking wet and has the biggest crack. I could repair the other cylinders, but #3 is beyond repair.
Found the gasket set in New Jersey for $129.00, but that head is killing me. After a lot of looking I found that grainfarmer.com list them for $799.00 plus shipping.
Has anyone else had this problem? Does it happen a lot with these engines, crack the head that is? Have tried almost the entire East Coast looking for a used head...none to be found. So...is that about what I should expect to pay for a head?
Thanks for any help or tips you can give me.
 

skidboy

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Welcome to V1702 Kubota Engines. Very common problem as a lot of owners were'nt aware that underneath the radiator is an oil cooler,and it is not visible if the cooler or radiator get plugged with grass feathers etc.You got the machine cheap,put a new head on,clean the cooler and radiator,fill with coolant and away you go.
 

Tazza

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Welcome to V1702 Kubota Engines. Very common problem as a lot of owners were'nt aware that underneath the radiator is an oil cooler,and it is not visible if the cooler or radiator get plugged with grass feathers etc.You got the machine cheap,put a new head on,clean the cooler and radiator,fill with coolant and away you go.
These engines are known for cracking heads. They get hot and POW new head time. Crack repair really isn't an option, they mostly crack around the pre-comps and between valves. Small cracks can be repaired with A plugs but i really don't know how long it will last. Some spots are pretty thin like where the water jacket is.
Second hand heads are like hens teeth, at least new ones are still available. I think they are made in china and not by Kubota but i think the quality is just as good.
 

MWorld

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Aug 10, 2007
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Welcome to V1702 Kubota Engines. Very common problem as a lot of owners were'nt aware that underneath the radiator is an oil cooler,and it is not visible if the cooler or radiator get plugged with grass feathers etc.You got the machine cheap,put a new head on,clean the cooler and radiator,fill with coolant and away you go.
Thanks for input guys.
When we took the grill off the top to get to the radiator it was quite evendent that the bolts hadn't been removed in quite a long time. Guess the guy I got the machine from only checked the bottle on the bottom and never took the cap off the radiator to check the coolant level.
Grainfarmer.com dropped the ball and now can't ship the head so I'm getting the head and gaskets from Engine Distibutors in Blackwood, NJ.
Bare head....$814.50 Head Gasket set....$123.70
You're right about there being a lot of junk up inside fan area. The oil cooler is loaded. Am sure that contributed much to the problems. Everything seems to be coated with oil back there, possibly the rear seal is leaking.
As far as labor intensity goes, I'd rather change these heads all day than a 4.6L Lincoln.
Read someplace on this forum the valve clearances, but now can't find, would someone happen to know?
 

Tazza

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Thanks for input guys.
When we took the grill off the top to get to the radiator it was quite evendent that the bolts hadn't been removed in quite a long time. Guess the guy I got the machine from only checked the bottle on the bottom and never took the cap off the radiator to check the coolant level.
Grainfarmer.com dropped the ball and now can't ship the head so I'm getting the head and gaskets from Engine Distibutors in Blackwood, NJ.
Bare head....$814.50 Head Gasket set....$123.70
You're right about there being a lot of junk up inside fan area. The oil cooler is loaded. Am sure that contributed much to the problems. Everything seems to be coated with oil back there, possibly the rear seal is leaking.
As far as labor intensity goes, I'd rather change these heads all day than a 4.6L Lincoln.
Read someplace on this forum the valve clearances, but now can't find, would someone happen to know?
Clearance at TDC is .007 - .009 i work on .008 as its a mid-point.
I will need to look up head bolt tension if you need them.
That gasket sounds a bit pricy, i can get an aftermarket FULL gasket set for around $170 AUD.
Have a look at http://www.tractorimports.com.au/shop/categories.asp?cID=41
OR www.tractorimports.com.au then follow the links.
With the bare head, do remember you will need to get the valves ground and the stems may be worn. Just keep this all in mind, there is no point in half doing the job. You will also need valve stem seals.
Good lock with it. If you have any questions just let me know, i have done a few of these before and i have the manual for it too.
 

MWorld

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Clearance at TDC is .007 - .009 i work on .008 as its a mid-point.
I will need to look up head bolt tension if you need them.
That gasket sounds a bit pricy, i can get an aftermarket FULL gasket set for around $170 AUD.
Have a look at http://www.tractorimports.com.au/shop/categories.asp?cID=41
OR www.tractorimports.com.au then follow the links.
With the bare head, do remember you will need to get the valves ground and the stems may be worn. Just keep this all in mind, there is no point in half doing the job. You will also need valve stem seals.
Good lock with it. If you have any questions just let me know, i have done a few of these before and i have the manual for it too.
You're right, I do need the torque specs...can't find them on Alldata or Identifix. Would appreciate it if you could provide them.
Had to run the injector up to have them tested...they all failed. Should have them back tomorrow and then install head.
Here's a peek at it.
http://www.hurlbut.info/BobCat/
Thanks for the help.......John
 

Tazza

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You're right, I do need the torque specs...can't find them on Alldata or Identifix. Would appreciate it if you could provide them.
Had to run the injector up to have them tested...they all failed. Should have them back tomorrow and then install head.
Here's a peek at it.
http://www.hurlbut.info/BobCat/
Thanks for the help.......John
Ok, i will do my best to remember. If i doforget send me an e-mail. taz38sup at yahoo.com.au at = @ of course. You can send me one anyway to make sure i do remember.
Thats a bad crack. You can really see its been using some water!!!
 

Tazza

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Ok, i will do my best to remember. If i doforget send me an e-mail. taz38sup at yahoo.com.au at = @ of course. You can send me one anyway to make sure i do remember.
Thats a bad crack. You can really see its been using some water!!!
Head bolt torque 55-58 foot pounds.
Rocker arm nuts 18-20 foot pounds.
Firing order is 1-3-4-2
I trust you know how to find TDC on number 1? if not, look on the front pulley, it has marks for all 4 pots. Work on the TC marks not the FI (fuel injection) ones. There should be a pointer at the base of the water pump.
Let us know how you go.
 

Tazza

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Head bolt torque 55-58 foot pounds.
Rocker arm nuts 18-20 foot pounds.
Firing order is 1-3-4-2
I trust you know how to find TDC on number 1? if not, look on the front pulley, it has marks for all 4 pots. Work on the TC marks not the FI (fuel injection) ones. There should be a pointer at the base of the water pump.
Let us know how you go.
From all that black oil, i do think you have a rear main seal leak..
The good news is they are a piece of pie to replace. You just need to remove the fly wheel and then remove about 20 bolts to remove the rear main seal carrier. No major disassembly is required.
 

MWorld

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From all that black oil, i do think you have a rear main seal leak..
The good news is they are a piece of pie to replace. You just need to remove the fly wheel and then remove about 20 bolts to remove the rear main seal carrier. No major disassembly is required.
You make it sound easy to change the rear seal. I assume the the cab has to be raised and tilted back and then the drivers seat removed gain access.
 

MWorld

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From all that black oil, i do think you have a rear main seal leak..
The good news is they are a piece of pie to replace. You just need to remove the fly wheel and then remove about 20 bolts to remove the rear main seal carrier. No major disassembly is required.
This puppy purrs like a kitten...or is that a paradox.
Now to clean it down.
 

Tazza

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This puppy purrs like a kitten...or is that a paradox.
Now to clean it down.
Glad its alive again!
To replace the seal you need to pull the engine out. This will be good to allow cleaning.
Just remove the attached hoses and throttle linkage, remove the 4 bolts holding the engine to the chassis and pull it out and up over the lip on the back.. I used a small air hoist with a chain joining to the 2 lifting points on the head.
To put it back in is a little more tricky, you need to lift the engine back in, slide it back but not all the way, you need someone laying on the hydro pump to hold the drive to the pump and get it to line up then slowly sneak it forward with pry bars.
After you have done it a few times its pretty simple.
If you pull the engine, ensure you grease the universal joints! its a pain to grease when its back in the machine.
 

MWorld

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Aug 10, 2007
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Glad its alive again!
To replace the seal you need to pull the engine out. This will be good to allow cleaning.
Just remove the attached hoses and throttle linkage, remove the 4 bolts holding the engine to the chassis and pull it out and up over the lip on the back.. I used a small air hoist with a chain joining to the 2 lifting points on the head.
To put it back in is a little more tricky, you need to lift the engine back in, slide it back but not all the way, you need someone laying on the hydro pump to hold the drive to the pump and get it to line up then slowly sneak it forward with pry bars.
After you have done it a few times its pretty simple.
If you pull the engine, ensure you grease the universal joints! its a pain to grease when its back in the machine.
You make me laugh...lol
So it's a piece of pie to change....Let the friggin thing leak for a while. I have an old style steam cleaner that I'm going to use to clean it all out with. I hope there are drain holes on the bottom.
 

MWorld

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Aug 10, 2007
Messages
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Glad its alive again!
To replace the seal you need to pull the engine out. This will be good to allow cleaning.
Just remove the attached hoses and throttle linkage, remove the 4 bolts holding the engine to the chassis and pull it out and up over the lip on the back.. I used a small air hoist with a chain joining to the 2 lifting points on the head.
To put it back in is a little more tricky, you need to lift the engine back in, slide it back but not all the way, you need someone laying on the hydro pump to hold the drive to the pump and get it to line up then slowly sneak it forward with pry bars.
After you have done it a few times its pretty simple.
If you pull the engine, ensure you grease the universal joints! its a pain to grease when its back in the machine.
Another question. Seeing as I'm new to all this, what is the foot pedal in the center for? I understand the left is to raise the bucket and the right is to tilt the bucket, but have no idea what the center one is for.
Acorss the top in the guage panel are two lights. Is the left one the glow plugs and the right oil pressure? The red plastic covers are worn so it's rather hard to understand them.
Regrettably someone has taken off the serial number plate that was on the back. All that's left are two half rivets.
 

MWorld

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Aug 10, 2007
Messages
16
Glad its alive again!
To replace the seal you need to pull the engine out. This will be good to allow cleaning.
Just remove the attached hoses and throttle linkage, remove the 4 bolts holding the engine to the chassis and pull it out and up over the lip on the back.. I used a small air hoist with a chain joining to the 2 lifting points on the head.
To put it back in is a little more tricky, you need to lift the engine back in, slide it back but not all the way, you need someone laying on the hydro pump to hold the drive to the pump and get it to line up then slowly sneak it forward with pry bars.
After you have done it a few times its pretty simple.
If you pull the engine, ensure you grease the universal joints! its a pain to grease when its back in the machine.
Would you happen to have a schematic for wireing the alternator?
 

Tazza

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Would you happen to have a schematic for wireing the alternator?
The lights are not for glow, they are for engine oil pressure and charge pressure/temperature. They both should be lit when you turn the key then when started they should go out.
I do have a schematic but its very bad detail, its really no good to work from. I wired mine up to the key switch, i used the accessories circuit that runs the gauges. I ran mine through a diode so when its excited it draws no more power. Not sure if its really needed but it used to have one so i put one in.
Engine out isn't that hard, seriously! With 2 people and a hoist it really is a piece of pie.
There are no drain plugs as such, but there are points in the back corners that dirt/sludge can escape. They are small so you will no doubt need to keep poking them clear.
From the pictures of the machine i saw, you have one of the earlier machines. From the description of the instrument panel that leads me to think its an early 80's model too. I had one of these with clark 743 on the side and the panel was the same.
 

Tazza

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The lights are not for glow, they are for engine oil pressure and charge pressure/temperature. They both should be lit when you turn the key then when started they should go out.
I do have a schematic but its very bad detail, its really no good to work from. I wired mine up to the key switch, i used the accessories circuit that runs the gauges. I ran mine through a diode so when its excited it draws no more power. Not sure if its really needed but it used to have one so i put one in.
Engine out isn't that hard, seriously! With 2 people and a hoist it really is a piece of pie.
There are no drain plugs as such, but there are points in the back corners that dirt/sludge can escape. They are small so you will no doubt need to keep poking them clear.
From the pictures of the machine i saw, you have one of the earlier machines. From the description of the instrument panel that leads me to think its an early 80's model too. I had one of these with clark 743 on the side and the panel was the same.
BUGGER!
Forgot to tell you what the pedal in the centre is, its the park brake. With it tipped forward the machine shouldn't move. If it does move, tighten the nut on that long shaft to make it tighter. If that doesn't work you will need to replace a few brass pucks inside the chain case, this is a pain to do this if your machine has a one piece plate where the steering levers go through. It needs to be removed to gain access.
The pedal doesn't need to be super tight to tip forward, they are pretty strong even with light pressure on the pedal it should stop the machine from moving. Remember this is a park brake only don't try and stop a moving machine with this, it will cause damage.
 

tjc

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Mar 18, 2022
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Welcome to V1702 Kubota Engines. Very common problem as a lot of owners were'nt aware that underneath the radiator is an oil cooler,and it is not visible if the cooler or radiator get plugged with grass feathers etc.You got the machine cheap,put a new head on,clean the cooler and radiator,fill with coolant and away you go.
I just put a second head on mine in 8 years, it got hot a couple of times and bamm there went my head. I flushed the radiator, and the hydrolics seem to flow very well, however I have not got it running yet hose leaks. I got my head from Amazon with gaskets for 609 total. It's a great machine when it's running properly. Good luck I hope everything works out for you
 
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