Intake blows white smoke, no start

[FlyAHull]

New to the forum. Searched a bit before posting. I have a new to me B6100e with a D650. Tractor sat for many years in a shed after owners got discouraged having bought it used and stopped running soon after purchase. They said they brought it home, ran once and never ran again.

Symptoms: when cranking, intake blows white smoke. no noticeable exhaust pressure felt along exhaust ports

Troubleshooting performed: 1. Adjusted valves, no change, 2. Pulled head, confirmed no warpage or blown head gasket or cracks, 3. Reseated valves using grinding paste, 4. Replaced head gasket, 5. Reassembled, set timing by pulling idler gear and aligning all marks, 5. Set valves

Still blows out intake. Looking for suggestions.

 

[85Hokie]

An intake valve is sticking open is my best guess

 

[FlyAHull]

I’ve no experience with anything other than a “stuck” valve which is visually easy to detect as it does not move. For a sticking valve, is there a method of detecting?

 

[woodman55]

There are keys for the crankshaft, camshaft, and injection pump gears. Maybe it sheared one when it quit on the last owners. That would through it out of time. It maybe out enough to through it out of time and not run, but not enough to bend valves.

 

[FlyAHull]

Woodman, I inspected and set the timing marks between injector pump, cam and crank and don’t suspect timing slip. However, it almost seems as though the intake and exhaust valves are opening in reverse order from what I would expect.

when I rotate the crank (counter clockwise, looking at the front of engine), the intake valve opens, closes and immediately followed by the exhaust open/close then a full revolution with no movement (power stroke cycle?).

im using the following vid as reference for diesel engine cycle:

 

[lynnmor]

I’ve no experience with anything other than a “stuck” valve which is visually easy to detect as it does not move. For a sticking valve, is there a method of detecting?

Since you adjusted the valves it should have been apparent if a valve was sticking while doing the adjustment.

 

[woodman55]

It sounds right other than looking at the front of the engine it should be turning clockwise, counter clockwise if looking at the flywheel end. When you turn it with the starter, which way does it turn ? If it is turning backwards, that would explain a lot.

 

[FlyAHull]

Looking directly at front of engine, starter turns crank in CCW direction….

 

[woodman55]

Interesting. Most engines turn opposite that. If you lower the 3pt all the way down, then move the lever to raise, then crank the engine and the 3pt starts to lift, then we know for sure the engine is turning in the correct rotation. Another way would be to connect a engine oil pressure gauge and see if it builds pressure while cranking.

 

[FlyAHull]

Getting the manual pressure gauge out now to test.

 

[FlyAHull]

the Starter does not look factory or original. Have not looked but any chance the mower is positive ground like older turn of the century tractors?

 

[North Idaho Wolfman]

No it's not a positive ground tractor.
The motor should be turning CW NOT CCW.
The starter is spinning it the wrong direction.

The only way for that to be possible is the starter is wrong, how it's wrong is beyond me, because for it to spin the motor the opposite direction it not only has to spin backwards, but has to have the Bendix made backwards too.

 

[GreensvilleJay]

so maybe the battery is wired up backwards ??
1st place to check
someone may have installed a -R battery. correct rating but REVERESD terminals.

 

[armylifer]

There is one more possibility concerning the battery. If a charger was connected to the battery in reverse, with the positive connected to the negative post the battery would take a reverse polarity charge. That would cause the starter to turn backward even if you have the cables connected to the correct positions on the starter.

Normally, the newer battery chargers these days will not allow you to hook up to the wrong terminals, even if the battery was completely dead, but older chargers will, even solid state chargers from as recent as 30 years ago. If the battery was near completely dead the circuit breaker on the battery charger still may not trip if the battery was dead enough. That would cause a reverse polarity charge to the battery. It is possible to correct this condition by letting the battery go completely dead and charging it again with the polarity correct. This happened to me once many years ago. That is how I found out about this possibility.

 

[ruger1980]

so maybe the battery is wired up backwards ??
1st place to check
someone may have installed a -R battery. correct rating but REVERESD terminals.

No you can reverse polarity on a Starter and it will turn the same direction. Besides the starter drive would not function if the starter ran backwards because it is a one-way over running clutch.

Like NIW stated if the engine is cranking CCW when looking at the front of the engine the starter is incorrect

 

[GreensvilleJay]

hmm, hadn't thought about the 'bendix' unit.....
now curious as to the part number on the tag of the actual starter. Wonder if Google will find it
Also interesting that someone, somewhere makes an engine with same block as Kubota, yet engine runs 'backwards' .
Maybe that starter is for a boat ???

 

[TerryKing]

hmm, hadn't thought about the 'bendix' unit.....
now curious as to the part number on the tag of the actual starter. Wonder if Google will find it
Also interesting that someone, somewhere makes an engine with same block as Kubota, yet engine runs 'backwards' .
Maybe that starter is for a boat ???

COULD Be.. Twin inboards sometime ran second engine opposite rotation. Mainly different camshaft and different starter. The flywheel starter ring is straight cut.
Does Kobota sell a Marine engine...??Regards, Terry

 

[MountainMeadows]

If the bendix drive was frozen and the battery hooked up backwards this would cause the starter to run backwards. I'd pull the starter, check the bendix, and test run it off the tractor.

 

[GreensvilleJay]

well it's confusing...
One website for the starter says it turns CW, which means engine will turn CCW. Well from the ringgear end of the crankshaft..... Need to know the 'frame of reference'. If looking at the crankshaft pulley, which way SHOULD the engine turn ?

Messicks says $450+- for starter, other guys $250+-...

 

[Henro]

As Ruger1980 said above, since the starter is a series DC motor you can reverse the voltage polarity applied to it and it will still rotates in the same direction regardless.

The way you reverse direction of a series DC motor (series meaning the armature and field or connected in series) is your reverse physically one of those two windings. Difficult to do with an automotive type starter motor (Without somehow rewiring it internally).