[QUOTE=newguy;20403]Kubota 15951-65512. Usually about $12 from farm supply places.[/QUOTE]

Save yourself even more money and grab a set of NGK Y-103V glow plugs... About $5.49 each at you local auto parts store....

[QUOTE=ajcastagno;20682]Finally got my glow plugs and went to install them.... They did not fit my M25XPB....

I ordered NGK Y-103V 15951-6551-3 The threaded part is too thick... Any thoughts?

Tony[/QUOTE]

That is odd.. Can you get a part # off the old ones. Clean the paint off with a wire brush. Perhaps the M-25XPB uses different plugs than the M-25......?

I used the cross reference from post #3 and that is correct but it appears it is for an M-25 or M-25XP not the M-25 XPB.

As near as I can tell the M-25 XP[B]B[/B] takes Kubota part number: 15521-65512 and this crosses over to an NGK Y-106V

The Y106V and Y103V are both M10 X 1.25 plugs so the 103V's should be the same diameter.

The Y103V is 72mm long with a 17.5mm glow tip
The Y106V is 75 mm long with a 16.5mm glow tip
Both are an M10 X 1.25 Thread
Both use a 12MM Socket for the Hex

I would say we need to confirm the M-25XPB is a Kubota D1005 engine block then find that Kubota part # then I can get you the NGK cross..

Tony, have you considered taking one off your engine and bringing it into the auto store?

I might have been in error on my original posting. Seems like there's lots of conflicting information on what glow plugs go into the Kubota D1005 block. I have yet another cross reference that indicates that a NGK Y709R is the correct one. Don't install a plug that does not look very close to the one you removed.

One ray of hope is that there's nothing wrong with your glow plug. Testing is easy because they are just resistance heaters. You should measure about 1.5 ohms from the terminal (wire removed) to the engine block. With the plug out, the same 1.5 ohms between the wire terminal and the threaded portion of the plug.

Let me know what you find out as I'm trying to put a cross reference together.

I found and used this cross reference a few years ago. I used the ngk number from the old glow plugs, and found the new number here: nhttp://www.ngkpartfinder.co.uk/cross_reference.php?type=GLOW+PLUGS

I bought the replacement ngk glow plugs from Amazon. I presume they still have them.

AND; (since no one has asked yet...) does anyone have the cross-ref for the M35B??? :D

[QUOTE=HowLin;20726]AND; (since no one has asked yet...) does anyone have the cross-ref for the M35B??? :D[/QUOTE]

The best way to cross reference is to get the # right off the glow plug. It can then be directly crossed over to NGK. I have the NGK catalog with cross references but had never seen the web site..... Unfortunately NGK only lists Kubota not Universal/Westerbeke so you need to cross your block over to Kubota first....

Most Kubota engines have an antechamber where the intake air, fuel, and glow plug meet and this heated mixture is drawn into the main combustion chamber by the downward stroke of the piston. Getting the glow plug length correct ensures that the probe end is extending the correct amount into the antechamber.

Glow plug failures are uncommon, and like the ignition system in an outboard, often incorrectly blamed for issues with fuel metering. Remember, you're not heating the block, just the mixture. Most glow plugs reach design temperature in about 10 seconds with a healthy battery.

For what it's worth, my 1999 M35BC is on a Kubota V1305D block... Kubota S/N 16060

Glow Plugs:

[B]Engine and Block.............................................NGK........Tractor[/B]
Universal M-25 is a Kubota Block D850..................Y-103V......B6200
Universal M-25XP is a Kubota Block D950...............Y-103V......B7200
Universal M-25XPB is a Kubota Block D1005............YE-01.......ZD362
Universal M-35, M-35A is a Kubota Block V1200......Y-103V......B9200
Universal M-35B is a Kubota block V1305...............YE-01........B2710

If anybody knows different, please advise.

Tony, if your batteries have a 'resting' voltage of only 12.0, they are shot or your charging system is. Even a good strong bank can see the voltage down at the starter motor near 10V while cranking. Adequate cable size and clean, tight connections are very important.

If you don't hear a good, fast cranking speed, I would address that first.

Tony -
I know we corresponded on this subject in a different thread -- [url]http://www.c36ia.com/forums/showthread.php?t=2553[/url] -- but do you have a solenoid installed to deliver power directly to the glow plugs? Your glow plug itself may test out fine on the bench, but, as Duane notes,
[QUOTE=deising;20810]Adequate cable size and clean, tight connections are very important.[/QUOTE]

If you don't have a solenoid, the long cable run from the engine to the instrument panel can cause a significant voltage drop and a corresponding increase in the time that the glows plug switch must be activated. A solenoid can bypass that run and deliver some serious amps to the plugs (after we added a solenoid the cold start time dropped from 45 seconds to 10 seconds). An easy and inexpensive modification, see upgrades section:[url]http://www.c36ia.com/node/916[/url]. This may not turn out to be the cure, but certainly a cheaper place to start than replacing all the batteries.

Each glow plug will use about 10 amps for 10 seconds. To get glow plugs hot in the first place you need a good battery. If your battery is at the end of it's life, then by the time you hit the start button you either have not gotten the plugs hot enough or there's not enough juice to turn the engine fast enough. Perhaps both.

Unlike a gasoline engine where the air/fuel fuel charge is ignited by a spark, a diesel's air/fuel charge is ignited by mere compression. Since cylinders have a certain amount of leakage past the rings and valves, you have to get the piston moving up at a good clip on the compression stroke to beat the leakage. In Otto-cycle engines, timing is everything....