B6100 3 cylinder wont start

[Roadman1122]

I have a Kubota B6100, great tractor, i never had a problem.

i drove up to the house in late summer, shut it off like normal. came out the next day it wont start. replaced the fuel filter, glow plugs, injectors. and it still wouldn't start. checked compression, all three cylinder above 400 psi. pulled the glow plugs, watched them work good, pulled the injectors and fuel is spraying. also bleed the lines numerous times. still nothing, is sounds like it trying but wont. if anyone has any suggestion, i would help.

 

[eserv]

I have a Kubota B6100, great tractor, i never had a problem.

i drove up to the house in late summer, shut it off like normal. came out the next day it wont start. replaced the fuel filter, glow plugs, injectors. and it still wouldn't start. checked compression, all three cylinder above 400 psi. pulled the glow plugs, watched them work good, pulled the injectors and fuel is spraying. also bleed the lines numerous times. still nothing, is sounds like it trying but wont. if anyone has any suggestion, i would help.

Not a lot to go on, Could be as simple as the three point hitch lever too far back causing a load on the engine while trying to start?

 

[Russell King]

I have a Kubota B6100, great tractor, i never had a problem.

i drove up to the house in late summer, shut it off like normal. came out the next day it wont start. replaced the fuel filter, glow plugs, injectors. and it still wouldn't start. checked compression, all three cylinder above 400 psi. pulled the glow plugs, watched them work good, pulled the injectors and fuel is spraying. also bleed the lines numerous times. still nothing, is sounds like it trying but wont. if anyone has any suggestion, i would help.

You obviously know you need three things for the diesel engine to run, air, fuel and compression.

You say you have the fuel and the compression but didn’t comment on the air intake or filter. Verify you have good air flow into the engine.

But if all cylinders have 400 PSI I would suspect your measurements since that is pretty high for an older engine (which I think a B6100 engine would have a few hours on it by now). How did you measure the compression?

 

[Russell King]

But do NOT try using starting fluid (ether) on it ever.

 

[Roadman1122]

You obviously know you need three things for the diesel engine to run, air, fuel and compression.

You say you have the fuel and the compression but didn’t comment on the air intake or filter. Verify you have good air flow into the engine.

But if all cylinders have 400 PSI I would suspect your measurements since that is pretty high for an older engine (which I think a B6100 engine would have a few hours on it by now). How did you measure the compression?

I do have the air intake off, no filter, I have a 22 mm diesel compression kit, I removed the injectors and tested there, I did a dry test and a wet test, wet was great, dry no so good.

Wet was 425 on all three, dry test was 240 on one 70 on the other two.

 

[eserv]

I do have the air intake off, no filter, I have a 22 mm diesel compression kit, I removed the injectors and tested there, I did a dry test and a wet test, wet was great, dry no so good.

Wet was 425 on all three, dry test was 240 on one 70 on the other two.

So the rings (and probably the pistons and sleeves) are shot

 

[Roadman1122]

So the rings (and probably the pistons and sleeves) are shot

Should the compression reading be tested wet or dry?

 

[Russell King]

Dry as far as I recall

How much oil did you put in each cylinder? I think there is some chance of hydro locking if too much oil is added and not spun out before testing. But I have no idea what too much is in any measurement!

 

[eserv]

Should the compression reading be tested wet or dry?

The dry test tells you what the actual compression is. The wet test is to determine if it is the valves or the piston rings causing the low compression. If your numbers are correct your engine won't start. I recommend a leakdown test rather than a wet test because of the danger of damaging the engine and the compression tester if you hydrolock the engine.

 

[North Idaho Wolfman]

How did it start before this no start event?
If it started and ran fine before this, then having it not start all the sudden is really odd.

Does this have a decompression knob and cable or linkage going to the valve cover?
That would explain everything.
Have you had the valve cover off of it and checked the valves?