B1550 not starting after replacing cylinder head

[jamesrhansen]

Okay, I got that the valves were set. At the risk of offending though, did you rotate the engine so the valves were completely closed when you set the clearance? I know it's a stupid question for someone who knows what he's doing but I've had to stop myself from time to time and go back and do it right.

You are not offending me at all and in no way an expert this is actually my first time replacing the cylinder head. I replaced the head gasket once previously. I did rotate the engine so the valves were closed.

I received my diesel tester this afternoon.
I never did a compression test but from what i read the engine specs say 450 PSI standard and 325 lower limit

I will do the following;

remove all glow plugs
shut fuel off
remove air filter
connect tester to one cylinder
crank engine until i get a reading 10-15 seconds
repeat for the remainder of the cylinders

Is this the correct way to do it ?
I will do a dry test first
Someone also mentioned after doing the dry test to squirt some oil in the glow plug hole and do a wet test is a wet test also suggested?

I will post the PSI results by the end of the day on Sunday

I appreciate your help and I am a total novice at this

Thank you

 

[whitetiger]

You stated: "I did rotate the engine so the valves were closed. "
There are a few more steps to adjusting the valve lash. See PDF below.

 

[jamesrhansen]

You stated: "I did rotate the engine so the valves were closed. "
There are a few more steps to adjusting the valve lash. See PDF below.

I have the entire workshop manual for the tractor I bought a few years ago so I followed the same sheet you provided me.

Thanks
PS If anyone else needs any page from the workshop manual I will gladly scan it and send it to them it pays to share information !!

 

[jamesrhansen]

You are not offending me at all and in no way an expert this is actually my first time replacing the cylinder head. I replaced the head gasket once previously. I did rotate the engine so the valves were closed.

I received my diesel tester this afternoon.
I never did a compression test but from what i read the engine specs say 450 PSI standard and 325 lower limit

I will do the following;

remove all glow plugs
shut fuel off
remove air filter
connect tester to one cylinder
crank engine until i get a reading 10-15 seconds
repeat for the remainder of the cylinders

Is this the correct way to do it ?
I will do a dry test first
Someone also mentioned after doing the dry test to squirt some oil in the glow plug hole and do a wet test is a wet test also suggested?

I will post the PSI results by the end of the day on Sunday

I appreciate your help and I am a total novice at this

Thank you

cylinder one front of engine 50 PSI
cylinder two middle cylinder 80 PSI
cylinder 3 I did not test since I would have to remove the air intake pipe in order to test it.

Definitely a compression issue problem is how to I resolve it ?

I ordered a brand new head gasket from Kubota and I will get it Monday. A friend of mine told me to lap the valves however I don't know how to do that.

Any other suggestions I would appreciate it

Thanks

 

[jamesrhansen]

cylinder one front of engine 50 PSI
cylinder two middle cylinder 80 PSI
cylinder 3 I did not test since I would have to remove the air intake pipe in order to test it.

Definitely a compression issue problem is how to I resolve it ?

I ordered a brand new head gasket from Kubota and I will get it Monday. A friend of mine told me to lap the valves however I don't know how to do that.

Any other suggestions I would appreciate it

Thanks

I just watched a bunch of videos on you tube it seems pretty easy to lap the valves with the compound and lap tool. Going to pull the head and try to lap the valves this week wish me luck it actually seems pretty easy to do.

I will update once I am done and put the cylinder head back in with new head gasket and lapped valves.

Fun stuff

 

[Dave_eng]

Do you have an air compressor?

Before removing the head, put each cylinder in turn at TDC ( both valves closed) and then inject compressed air in the same way you did the compression test. Do it in a way where you can maintain the air pressure in the cylinder. Observe where the air is escaping. Out the exhaust or intake would reveal a valve seal problem. Out the crankcase vent, a problem with piston rings. Out the radiator ( have rad cap off) and you have more cracks in the block or a gasket issue.

Before you remove the head you want to know what is wrong.

Dave

 

[200mph]

I'm a bit surprised at the low compression ratio after installing new head and new gasket.

When the head was off, were:

• The piston tops and cylinder walls inspected?
• Head bolt threads in blocked cleaned out real good to ensure proper clamp load was achieved during the bolt torquing process?
• Lubricant/sealer applied to threads and under under bolt head if directed to by WSM
• Head and block checked for flatness
• Head and block surfaces clean before installing the new gasket?

I'd be very frustrated to learn the valves we not leaking on a brand new head.

Or is the low compression a byproduct of starting fluid use?

I hope it is something minor.

 

[Pau7220]

Do a dry, then a wet test with a small amount of oil squirted in the cylinders. If there is no change the new valves may be leaking. If it's an aftermarket head could be they weren't lapped properly. After that charge the cylinders with air and listen for air leaking at the intake and exhaust.... also at the crankcase vent.
If there's a big change between dry and wet, it's a bottom end issue.
If you pull the head you'll need a new gasket.

When you skip steps it makes diagnosis more difficult.

 

[jamesrhansen]

cylinder one front of engine 50 PSI
cylinder two middle cylinder 80 PSI
cylinder 3 I did not test since I would have to remove the air intake pipe in order to test it.

Definitely a compression issue problem is how to I resolve it ?

I ordered a brand new head gasket from Kubota and I will get it Monday. A friend of mine told me to lap the valves however I don't know how to do that.

Any other suggestions I would appreciate it

Thanks

I lapped the valves twice each and the compression increased from 80 to 150 PSI on the ones that were at 80 PSI and one valve was sticking. Now all three valves are giving 150 PSI which is still below 350 PSI minimum for the tractor.

I need to get some fitting to inject air into the glow plug positions.

I will try that and see where the air is escaping

 

[Pau7220]

I need to get some fitting to inject air into the glow plug positions

You should be able to use the fitting that came in the compression tester. Where the gauge threads into the fitting on the hose it should be 1/4" NPT. There may be a schrader valve that needs to be removed.

 

[Pau7220]

one valve was sticking

Curious how you fixed this, and what was causing it?
If it was sticking open it probably screwed you up when you were adjusting them.... and you may have bent one or more if it was stuck open.
You lapped all the valves... were the compound marks consistent all the way around the valve face, and the seat? Cleaned and oiled faces and seats after lapping? Checked for bends?
You did state new cylinder head .... was this new aftermarket?
And it did run well and start easily before head replacement?

 

[jamesrhansen]

Curious how you fixed this, and what was causing it?
If it was sticking open it probably screwed you up when you were adjusting them.... and you may have bent one or more if it was stuck open.
You lapped all the valves... were the compound marks consistent all the way around the valve face, and the seat? Cleaned and oiled faces and seats after lapping? Checked for bends?
You did state new cylinder head .... was this new aftermarket?
And it did run well and start easily before head replacement?

Not fixed yet by lapping the valves I got them all at 150 PSI each. I think I need to do another valve lapping with different grits. I just ordered the loctite kit that has 120/280 grit compound
The valves looked consistent all the way around
I cleaned each valve head to remove the compound and with a different rag cleaned the stem. Then applied oil on each stem
The tractor ran with the old cylinder head but it over heated and it looks like there were minute cracks in it.
I purchased aftermarket cylinder head from Amazon. Stupid me lesson learned.
Once I lapp again using the two different grits I will use a new Kubota head gasket and try the compression test again.
Thanks

 

[jamesrhansen]

You should be able to use the fitting that came in the compression tester. Where the gauge threads into the fitting on the hose it should be 1/4" NPT. There may be a shrader valve that needs to be removed. View attachment 45843

This worked and screw into my air hose. I tried putting air into the head and it seems like it is going in however I don't hear air escaping but I do not have the best hearing so tonight I will have my wife listen for air escaping she can hear an ant fart

 

[Pau7220]

she can hear an ant fart

Too funny!!
If you have the head off, get a small amount of oil between the pistons and cylinder walls... That will give you the wet compression test. Also, rotate the engine and bring up each piston up to Top Dead Center and make sure it comes up to the top of the block. Since it's unknown how much coolant was in the cylinders, that's the way to check for bent rods. Check for a schrader (tire) valve in the adapter or hose also, it may be preventing air from going in since it's designed to hold pressure in the opposite direction.

 

[jamesrhansen]

Too funny!!
If you have the head off, get a small amount of oil between the pistons and cylinder walls... That will give you the wet compression test. Also, rotate the engine and bring up each piston up to Top Dead Center and make sure it comes up to the top of the block. Since it's unknown how much coolant was in the cylinders, that's the way to check for bent rods. Check for a schrader (tire) valve in the adapter or hose also, it may be preventing air from going in since it's designed to hold pressure in the opposite direction.

Quick update after going back and forth with the place I bought it from they determined after reviewing pictures they sent me the incorrect part. They are working on crediting my account in the meantime I tried ordering a new cylinder head from my local parts dealer and they are back ordered

Does anyone know what the stamp means on my old cylinder head

K6-B on left
40310 on right

I have an original parts manual for the tractor and it says
Part # Description
19267-0304-0 Comp. cylinder head

D850-B

 

[200mph]

You might want to consider purchasing a complete head with new valves this time around.

 

[jamesrhansen]

You might want to consider purchasing a complete head with new valves this time around.

The one I purchased had the valve installed. Problem it was sourced from China.

I am unable to find one anywhere so far

My old cylinder head has the following on it

K6-B on left
40310 on right

I have an original parts manual for the tractor and it says
Part # Description
19267-0304-0 Comp. cylinder head

 

[Mark_BX25D]

White smoke is either coolant or unburnt diesel.

I'm betting it's diesel and your compression is too low to ignite the fuel.

If the compression is good, check the speed of rotation when you are trying to start. If it's not fast enough, you won't generate enough heat to ignite the fuel.

 

[200mph]

Any luck finding a cylinder head and completing the rebuild?

 

[jamesrhansen]

Any luck finding a cylinder head and completing the rebuild?

I got a call from my Kubota Dealer and they said Kubota has discontinued the part and they are unable to source it from anywhere else. 19267-03040 D850 cylinder head.

I took the made in China cylinder head and my old cylinder head to a machine shop in my town and they are going to re-cut the valve seats and do a complete valve job on the new head. I should have it back next week so I will install it and test and update the forum witht he results

Thanks