kubota white smoke problem

[Texasjack]

It drools drops out of the exhaust, like rusty water... oil still looks good and runs fine...

[wg4t50]

Still sounds like crappy diesel fuel, still suggest running from a jug of good fresh fuel, see if it cleans up.
BTDT
Dave M

[junkman42]

Bad head gasket/head/precombustion chamber?  My educated guess.  John L

[Texasjack]

Ive been running her on a 5 gallon tank with some injector cleaner..Ran it maybe an hours worth.Still smoking. Oil clean. Everyone thinks its a head gasket or cracked head. With only 85 hours of total run time? Wow, that would make it the most expensive POS I have ever bought! lol

[OneLapper]

This may have been suggested, but try running it under max load with fresh fuel for several hours.  Partial load doesn't help.  Clean or replace the air filter even if you think it doesn't need it.  

Use a IR pyrometer to check the temps of the exhaust ports.  They should be very close, the one closest to the water pump is usually the coolest.   If one cylinder is cooler than the rest, there's an issue with that cylinder.  

As suggested, while the genset is running under load, crack an injector line, one cylinder at a time.  Watch for several minutes (yes, messy) and observe if smoke diminishes.  If so you have a leaky injector or low compression on the cylinder.  

You can check compression with a tester easily.  You can swap injectors to see if the temp difference moves.  

With any luck it's just a mouse nest in the air filter.  

How many years did it sit without running?

[opus]

Air filter would be black smoke.  How about a stuck injector is what I am thinking.

[OneLapper]

Air filter would be black smoke.  How about a stuck injector is what I am thinking.

Yes, if its completely clogged it can produce black or grey smoke.  If this engine only has a slight haze in the exhaust it'll be difficult to determine whats the cause.   Could be a partially dirty air filter, leaky injector or low compression.  

[c-coop]

I have seen this many times in our small marine gen sets Isuzu and Yanmar engines excess water or fuel on top of the piston when you go to start it puts a slight bend in the connecting rod which dosen't let the piston come completely to the top which causes lost compression and unburned fuel [white smoke]

[Geoff]

Try

[Texasjack]

Its has been run at least 2 times a year over the last 4 years.
Ill change air cleaner and check temps on cylinders, also other suggestions.
Iwo
uld like to exhaust my options before tearing her apart. Did i mention 4cylinder 20kw?