D722 starting

[North Idaho Wolfman]

Well just rechecked compression and iv lost most of it on cylinders one and two. Its coming to pieces again. I wont be using ether again. Its now come to light that someone has removed the pistons due to rings being stuck in the grooves, cleaned them out and fitted new rings. I must admit when it did start it cranked for ages and did breath a fair bit.
So I will do the job properly.
Thanks for the advice guys.

You need to check the length of the connecting rods.
with the rods and pistons installed check the height of the pistons, they should all be the same.
Commonly what happens with using ether on these engines is that is squishes the connecting rods.

 

[BruceP]

Commonly what happens with using ether on these engines is that is squishes the connecting rods.

YUP - this is what I was alluding to in post #2 when I said the con-rods bend like plastic.

The issue with Kubota (and many other diesel engines that use a 'precombustion chamber') ...... using starting-fluid causes IMMENSE explosion within combustion chamber BEFORE the piston reaches TDC.

Also check the valve-stems and rockers for bendege.... If you are fortunate, the block is not cracked.

 

[lugbolt]

You need to check the length of the connecting rods.
with the rods and pistons installed check the height of the pistons, they should all be the same.
Commonly what happens with using ether on these engines is that is squishes the connecting rods.

have you ever seen the upper rod bearings "flattened" from this? I have, but with suspected water ingestion (bent rods AND beat-out upper rod bearings). Also see it sometimes on the race car depending on what I do with fuel and timing. I measure the width before installation, and then measure them every time it's apart. They often tell me what is going on just by the width.

 

[North Idaho Wolfman]

have you ever seen the upper rod bearings "flattened" from this? I have, but with suspected water ingestion (bent rods AND beat-out upper rod bearings). Also see it sometimes on the race car depending on what I do with fuel and timing. I measure the width before installation, and then measure them every time it's apart. They often tell me what is going on just by the width.

Back in my days for racing I caused or seen quite a few squashed, bent, broken, and completely destroyed parts!
Amazing what you can do with to much HP!

 

[Stubby54]

Well just rechecked compression and iv lost most of it on cylinders one and two. Its coming to pieces again. I wont be using ether again. Its now come to light that someone has removed the pistons due to rings being stuck in the grooves, cleaned them out and fitted new rings. I must admit when it did start it cranked for ages and did breath a fair bit.
So I will do the job properly.
Thanks for the advice guys.

One more piece of advice please if anyone can help. I cant see damage to con rods but does anyone gave the correct length I can check them against please.

 

[BruceP]

One more piece of advice please if anyone can help. I cant see damage to con rods but does anyone gave the correct length I can check them against please.

I believe someone else mentioned before....

With head removed, turn crankshaft BY HAND and measure (depth gauge or other means) the top of each piston at TDC to the deck. ("deck" is where the head-gasket sits)

• If all pistons are same measurement... you can assume all the con-rods are OK and the lower end does not have to be disassembled.
• If any piston measures less than the others... that con-rod is bent.