-
Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
Kubota no start after new piston rings and head gasket
- Thread starter MrFritsch
- Start date
I got impatient and pulled it apart knowing it needed it anyhow. These are the pics of the cylinder walls. I can’t feel anything with my finger nail, looks shiny and glazed for sure with some marks. Picking up a home tomorrow morning before work. Do you recommend a ball or stone hone?
clueless2
Well-Known Member
They look like they were honed with a grinder by someone.
Have you miked them to see if they have much taper from wear ?
Have you miked them to see if they have much taper from wear ?
Truck Shop
Senior Member
Stone hone--Looks like cylinders were emery papered, part of the carbon soot line above
top ring is still there in some places.
*
Some photos of piston skirts.
top ring is still there in some places.
*
Some photos of piston skirts.
If you dont have a micrometer, take the rings off the piston and put top ring in cylinder. Then use piston to push ring down evenly. Use feeler guages to measure ring gap at multiple locations. This will give you an rough indication of wear in cylinders.
How long have you owned the machine?
I think someone has already been in there recently and its all bad.
How long have you owned the machine?
I think someone has already been in there recently and its all bad.
YIKES! Looks like #3 has a vertical gauld
All 4 cyclindars have vertical darker marks. I’ll check them with the ring and feeler gauges tomorrow! I bought the machine 2 weeks ago, started doing maintenance and paint on it, then the motor went out. The guy before me said they did a head gasket
clueless2
Well-Known Member
Good luck on honing the cylinders to stop the blowby.
Ain't gonna happen.
It needs new pistons and whatever you need to do to eliminate those nasty cylinder walls.
Ain't gonna happen.
It needs new pistons and whatever you need to do to eliminate those nasty cylinder walls.
Dave Neubert
Senior Member
That block needs bored not honed
A hard starting diesel engine quite often indicates low compression, especially on one with an unknown history. As said, you’re in for a rebuild. A decent cylinder will have no visible vertical scratches, let alone all of them. That many scratches can be caused by carbon buildup on the pistons. Are you sure you didn’t have tight valve lash before you tore it apart? As Truck Shop said, show us some pictures of the pistons- tops and especially the sides(skirts and ring grooves)
Truck Shop
Senior Member
Ok-----this is where issues come from trying to answer OP questions no matter the thread. Had all
of info been dumped out at first this would have taken about 4 replies to answer.
*
Strip it, have it machined, cleaned, engine rebuild 101.
That Kubota has press in sleeves that have to be finish honed. Thats why it's almost impossible to throw new rings in and it actually work.
Truck Shop
Senior Member
Yes--the correct way done with a wet tank hone.
Actually no sleeves at all. parent bore block. You can bore to .5mm oversize, unless that is done already, or if that doesnt get it perfect, or if no oversize pistons are available. Then you will need to bore out and install repair sleeves back to std.
Either way will need finish hone
Got them all honed, I used a feeler gauge on the piston ring in the cylinder like you guys suggested and it was well within specs. Got it back together and after a tremendous amount of bleeding fuel she fired up! The compression tester I ordered got pushed back so I didn’t get a number but she’s running again. Thanks for the suggestions everyone.
John V
Senior Member
What did you end up honing them with?