Reviving a G5200

[Blue280z]

I bought a G5200 with mower deck and stock D600 3 cyl, engine in July. It had ~3,300 hrs on the meter and needed TLC. Started right up cold and idled nicely.

I've done a bit of refresh so far (details in posts below) and have also been chasing the good ol' overheating issue.

I'll post progress on this thread to help others.

 

[Blue280z]

It has mostly stock parts. The 54" deck is from a Cub Cadet but a Previous Owner seems to have moved all the Kubota spindles, gear box and idlers from the rusty old Kubota RC48 to the modified Cub's deck. It was a well done job.

They also put a cub seat on it.


I did basic maintenance when I received it:

- downloaded owners manual and D600 maintenance manual
- power washed
- new fuel lines
- cleaned fuel tank
- greased & oiled appropriately
- new air filter
- two new diesel filters (the plastic one between the tank & pump, and the cartridge one in the engine compartment)
- new oil and transmission filters
- replaced oil and transmission fluid
- replaced mower gear box oil
- lubed mower spindles and idler
- removed rodents nest under battery
- drained radiator

First Round of Repairs:
- replaced missing rear wheel lug
- replaced oil dip stick (it leaked)
- installed tube in one front tire
- corrected parking brake latch issue
- put new rubber cover on parking brake pedal
- put a new rubber spring cap on the seat spring (must have lost it while shipping)
- installed new belt (this one is 102" X 5/8" due to the cub deck)

Some pics from the ad:

 

[Blue280z]

First go at mowing was disappointing. It overheated quickly and a lot of grey smoke under load.
It would work with less labouring when I cut with the deck at max height.... It would lose coolant out the overflow pipe when hot ....back to the drawing board:

Checked cooling system, found no thermostat so I guess the PO's also saw this problem and did what they thought would help,

When running from cold with the rad cap off, no apparent bubbles so no combustion gas getting in the coolant.

New thermostat and rad cap installed as well as the easy hoses to get to. Fan belt was not loose but I snugged it more.

Re-flushed rad with vinegar.

I also removed the injectors, disassembled and ultrasonically cleaned.

Removed fuel pump and checked for broken springs. All OK.

A cheap Diesel Compression tester showed all cylinders with equal compression but they all were well over the new spec so I assumed tester was Chinese junk and returned.

When I reinstalled the injectors and bled, I loosened the fuel to each slightly one at a time and the mower ran equally crappy when each cylinder was fuel starved so there does not seem to be a bad cylinder standing out.

Mowed more, it would warm-up faster to reach normal temp with the thermostat now in place (as expected) but, it was also slower to approach the red zone=. Sadly it woujd still reach 3/4 of the way to red on the gauge even with the deck all the way up and going slow. I'd stop mowing and idle when it went closer to the red.

The generator stay broke so I had to wait for new parts. The engine temp increased when this happened so the pump seems to be working.... how well is still in question.

Note: No oil in coolant, no coolant in oil, not burning oil, not burning coolant, only loosing coolant on high temp through rad over-flow tube when hot under load.... it can idle all day at a low temp.

 

[Blue280z]

Repaired the generator stay, straightened all fins on the radiator, used an AC condenser cleaning foam to extra-clean the rad. It looks clean inside. The removable screen was always clean.

Also used washing soda to flush the cooling system.

Adjusted valves cold to 0.165mm.

Played with the governor setting for full load. Added more fuel (hoping it would run cooler like a gasser) but it still heated up under load and now belched black smoke instead of grey smoke, reduced fuel and no smoke but no power under load. Re adjusted back to the grey smoke compromise.

Checked the FI injector timing and it was spot on.

In this state, it ran well but still heated up. The mower belt broke so we mowed with just the center blade and it never heated past 1/2 way on the gauge.

 

[Blue280z]

With all of the obvious checking out ok, I pulled the head. It looked great.



Nothing obvious observed on the head, deck, or on head gasket except 3 small cracks between each injector chamber and the intake valve.

HG Top

Block Top

Head Bottom

HG Bottom


Injectors and glow plugs look good with similar colour

Took the head to the engine shop. They said the cracks do not look bad and would not cause over heating. They pressure tested and all is good as well as straight.

This is where we are now (Aug 28). I will get them to do a valve job since the head is with them.

Ordered new head gasket, intake gasket, exhaust gasket, bolts, etc.

I am now looking at perhaps a larger rad or a fan swap with more blades; but will first see how the new HG does.

But before the cooling mods, I've ordered a new pump as the PO's were obviously "at it":

 

[Russell King]

There may be an oring on a pipe (dowel) that you will need to replace or at least be sure it is in place. (I am not 100% sure your engine has it but have read too many times about people not putting it on and having problems)

 

[Blue280z]

There may be an oring on a pipe (dowel) that you will need to replace or at least be sure it is in place. (I am not 100% sure your engine has it but have read too many times about people not putting it on and having problems)

Thanks! I believe it is this one: (part #140)?

 

[Russell King]

Yes that is the problem one that gets missed.

 

[Like Tractors]

Just got a G5200 with mower deck and stock D600 3 cyl, engine.... in late July. It still needs TLC. >3,000 hours.

I've done a bit of refresh so far (details in posts below) and have been chasing the good ol' overheating issue.

I'll post progress on this thread to help others.

I have an old G5200 that I bought new in 1993, it's kinda rough, but I still like it.

 

[Blue280z]

I have an old G5200 that I bought new in 1993, it's kinda rough, but I still like it.

Wow. It looks mint. Did you ever have overheating under load? I see the battery has been relocated. Was this for ballast or cooling or just battery up-sizing?

 

[Like Tractors]

Wow. It looks mint. Did you ever have overheating under load? I see the battery has been relocated. Was this for ballast or cooling or just battery up-sizing?

Long ago it would run kinda warm when using the bagger, I had a local radiator shop put a high efficiency radiator core in it, end of problem. I moved the batter because I got tired of that odd sized original size battery failing, group 24 battery out front, end of battery problem. It looks good because I am pretty fussy with my equipment.

 

[marine-mp]

You can also re-locate the battery to the rear of the machine and eliminate the overheating prolem. The original location, behind the radiator, was a poor design, causing for pp air flow. You’ll of course need longer cables!!!

Semper-fi & This We’ll Defend, Mike

 

[Blue280z]

Looks great Mike! Thanks! I will keep that in my back pocket for now. Love the throne you installed too! WOW!!!

Current status:

1. I asked engine shop to do a valve job, they report all valves need to be replaced. They said they were "too thin" but the seats and guides were fine? Kubota service shop said that valves can be damaged from heat so I'm going with it however, I have only seen burned exhaust valves on cars so I scratch my head for 3 intakes and 3 exhaust all to be bad. Internet search shows that some valves can tulip but the valves in the head seemed mighty fine in the pics above.



2. Waiting on valves at Kubota.

Once the engine is back up and running (new head gasket, water pump, valves, valve seal), I'll report back with a temperature update. After that it will be a battery relocate and new radiator.

 

[marine-mp]

Roger that, 280Z. JMHO, backflush the radiator, Clean the screen and relocate the battery. I put mine in back so I wouldn’t “hit stuff” if it was in the front!!! Terrible driver!! Also, gives more traction. I’m afraid the valve job was a result of the overheating, but you prolly already know that. Also, not to demean anything in any way, the “overheating” will most likely continue when mowing. It’s a know fact on these mowers w/the battery blocking the radiator. Whilst it’s down, it’s a great time to re-locate the fire-starter!! As I stated, JMHO, but talking from experience. Take care. Semper-fi & This We’ll Defend, Mike

 

[Blue280z]

Thanks! I will take your wisdom and experience and relocate the battery.

 

[Blue280z]

Update: Overheating issue solved.

Just mowed for 5 hours in heavy grass (mower was out of commission for a month so the grass got out of control)

It ran at 1/2 way on the gauge for most of the mowing but crept up just a little towards the third white tick-mark when in thick grass and clippings.

I'm not sure what fixed it as I could not do the repair one change at a time. Here is the group of changes made:

1. New head gasket
2. New water pump
3. New injector nozzles
4. New valves, valve seals, and valve job

It was expensive repair as Kubota part prices are "crazy high" here in Canada so I want to make this last. Better cooling will improve the life so 'll try relocating the battery as the next step then install an aluminum Honda Del Sol radiator.

I hope this helps others on the internet as there are so many overheating G5200 threads with no conclusions.

Runs like a champ!

 

[Blue280z]

Update:

I saw a lot of rust in the cooling passages after removing the head. This is after the vinegar flush and the washing soda flush; so I am now flushing with an evapo-rust equivalent. I just mowed for 3 hours and it is running even cooler. It seems to be working!

I'll leave the ER in the system for a week then replace with water.

I have a del sol 3 row aluminum radiator on order but may replace it next spring depending on time.

 

[Blue280z]

Kept the Evaporust in for ~ 6 weeks, drained, flushed twice with distilled water then put 50/50 coolant in for the upcoming winter. One last 4 hour mow and the temp never passed 1/2 way on the gauge. Outside temp was cool at 16C. Lets see how it does in the spring. The del sol radiator is waiting in the wings.

 

[marine-mp]

Hey Blue280z, dad-gum, souns like you got ‘er licked!! Good-on-yeh!!! Been a while. You got it fixed just in time to put it up for the season!!! Put some paint on it whilst it’s on vaca!! Take care an stay warm up there. From the sunny south…..Semper-fi & This We’ll Defend, Mike

 

[XYooper906]

Nice looking G5200! I purchased one last fall from the son of the late original owner with 470 hours on it. The son kept it for several years after his father passed, but used it very little, and finally sold it since he didn't have the need for it. You can tell it was the owner's pride and joy; it has a complete book full of purchase records, shop manual, notes, and a plastic tote filled with filters, deck rollers, hoses, belts, etc. The original 44" deck is on it.

I am currently overhauling and preserving the deck with all new spindle bearings and seals, gearbox seals and servicing, and cleaning up and sealing some very minor rust, and repainting it. I will also service the tractor fluids to get it ready for the upcoming season. Looking forward to using it!