743 smoking and quitting problems

[tommycalc]

I have a 743 Bobcat Kabota diesel, lately after I put a quart of oil in it the thing has been smoking from an overflow hose coming down from the top of the engine. At the same time when it gets hot it quits and is hard to start until it sits for awhile, at this time I have to prime it to start again. It gelled up on me a few weeks ago when it was really cold, ran for a while but quit and could not restart until I put some 911 in it and let it set for a couple of days, I have had these problems ever since. Can anyone shed some light on what may be happening, I was told I may have a cracked head.

 

[SSdoxie]

Any starting fluid or Ether used trying get engine to run when it was gelled? It sounds like rings are broken, cracked, or scored pistons which will happen using staring fluid on these engines.

 

[tommycalc]

no starting fluid was used. It is a diesel engine starting fluid is not good for such an engine I know this. has to be something else. thanks for your reply do you have any other thoughts on this.

 

[SSdoxie]

You may well have a cracked head, but the oil blowing out the crankcase vent means you have combustion gases going past the rings.

 

[tommycalc]

now the machine won't even start, it turns over but it does not seem to be getting any ignition to the fuel. The Glow plugs are getting hot, I bled the air out of the fuel line because it ran out of fuel and we put fuel in it. The filter is flowing fuel out of the check valve, but I get no fire. I am really at my wits end here.

 

[crashz]

If you have fuel to the injectors, then I'd check compression in each cylinder.

 

[truckdiagnostics]

can't explain the excessive blow by. However, i had similar issues several years ago. You have to pull the nozzles to check compression.... consider having the nozzles tested. If I remember correctly, the kabota nozzles inject into a pre-combustion chamber and spray patter is critical. When the spray pattern is off, it can cause knocking, hard starting and over fueling, the over fueling maybe the blow by you are seeing.
When I had them rebuilt, they said this was fairly common, and my nozzle issues started with jelling bad fuel ect., cost to fix it wasn't that bad.

 

[2458n]

Could be worn out. No compression means no start and alot of blow by when it does run.

 

[Mad Matt]

Have you not over filled the oil?

 

[laurencen]

has it overheated, had a similar issue on one we picked up used, got hot and cracked the head, hard to see but was defiantly cracked between the valves

rebuilt head and works fine