L2850 won't start, v1702 engine

[napabavarian]

I purchased a tractor today DOA, it won't start and the PO seemed to indicate it ran great then it didn't run at all.

I have hopen that it is something simple.

I haven't been able to verify GP functionality, but it is a warm day and my Vxx03 series engines fire right up even with thousands of hours.

Speaking of hours, this would normally be listed on Craigslist as "just broke in" or more accurately "just broken" @ 5800 hours, no compression test yet, I'll give that a shot tomorrow.

I was able to verify some flow to the injectors when I cracked the compression nuts, however it seemed like there was a bit of air in the lines at first.

I have not been able to check fuel return for aeration.

One strange point, I removed the stop plate cover to see if anything was obviously amiss, and what the heck, crank it over.

A cloud of fuel mist formed and escaped. Is this abnormal? It seemed odd, however I've never opened that cover before.

Thanks in advance for any ideas or pointers.

It does crank over very well, it doesn't sound slow however I can't say for certain, it does sound a bit softer than my bobcat, however that starts so fast I don't ever know what it sounds like cranking.

 

[kthompson]

Does that engine have a manual cut off beside the key cut off? Did you buy it sight unseen? Was it shipped to you? If so how was it unloaded? If it was advertise as running you may need to talk with lawyer, or police quickly. Did you pay for it with credit card? If so get a hold of them.

But back to the tractor: could the air flow have gotten blocked? Look at the air intake for say plastic shopping bag blown on it, look for insect nest in it. See if fuel flows through the filter. As to is it spinning fast enough, jump it to be sure you have plenty battery but that does not tell you the starter is turning it as fast as it should.

If you verify the air flow is open use WD 40 as starting fluid and if you have a helper to shoot short burst into the air intake while cranking it may start. If it cuts right off then not getting fuel. Start again and keep shooting short burst of WD 40 so it will run say 30 seconds to a minute. That should be long enough to prime it if it lost its prime.

Hope you well.

 

[davedj1]

My 2850 has a manual fuel shut off. Be sure that's pushed in.
Mine fires off almost instantly so not much cranking. Did they run it out of fuel?
Also, what shape is the tractor in, does it look beat to death or halfway decent?

 

[napabavarian]

I purchased it knowing it didn't run. It looks worn but not beaten to death, as I was looking it over and thinking about what he told me I started to wonder if it had the opposite problem, it was used for a nursery and the pto cover is still on it and the top link is missing, one of the holes is rusted as if it has been out for a while and there is no wear indicating heavy use.

This has led me to wonder if the rings are stuck from inadequate heat, low load operating. I think I may try an mmo soak tomorrow, if I want to spend the money I can grab some gm top end cleaner.

 

[napabavarian]

This morning I started to disassembling, removed intake for access, injectors are stuck in place. GPs came out too easily, I shot MMO in each cylinder, then I stuck a finger in each intake and wiped out with a blue towel. 1,3,4 all good, #2 was coked up to almost completely block flow. Any ideas on what would cause this?

Also, any tips for injector removal with basic tools? I'd like to test spray patterns.

 

[Thomas]

Really should make differents,but are you running enough RPM's?

 

[davedj1]

There aren't any hydraulic valves open so it's working the pump while trying to start? A guy I know had an old backhoe loader that the valve got hung up in the tilt mode and it stalled, acted like a dead battery until another buddy felt the pressure int he hose. We released the valve and it started right up.

 

[napabavarian]

Cranking speed sounds ok.

I can check valves to see how it looks

 

[napabavarian]

I soaked the pistons with MMO cleared it out and spun it over until it quit spraying from the gp holes.

Once I replaced the the GPs and cranked the engine over I found something interesting. ..

The intake manifold was off for easier access, #4 would emit a small puff of exhaust and reinhale.

#2 was more pronounced, it shot exhaust 6" +/- out the intake port. Typically this i's not the expected outcome.

I did remove the valve cover and all rockers depress the valves.

 

[napabavarian]

Kubota compression 260-120-250-390

 

[thepumpguysc]

Just check & adjust the vales before condemning the engine..
incorrectly adjust valves will have a big factor in compression readings.

 

[napabavarian]

I didn't do a proper check, but I had the valve cover off and all springs that weren't depressed were loose including the 2 on the lowest compression cylinder.

Are valve seats a common problem on these?

 

[thepumpguysc]

Not to my knowledge.. BUT cracked heads due to over heating.. YES.
They WILL NOT tolerate any heat..

 

[napabavarian]

Not to my knowledge.. BUT cracked heads due to over heating.. YES.
They WILL NOT tolerate any heat..

Would a cracked head push exhaust out the intake?

 

[thepumpguysc]

anything is possible..
Take a dollar bill & hold it over the muffler exhaust stack on a running engine, at idle.
IF the bill sucks in & blows out, you have valve/head problems..
IF it just blows away from the stack, your back at square 1..
but my money is on sucking back in..{valves}

 

[napabavarian]

If only it ran! Like the king said, off with yer head!

anything is possible..
Take a dollar bill & hold it over the muffler exhaust stack on a running engine, at idle.
IF the bill sucks in & blows out, you have valve/head problems..
IF it just blows away from the stack, your back at square 1..
but my money is on sucking back in..{valves}

 

[napabavarian]

Head is off, I poured some leftover mmo in the suspect cylinder and sure enough it starts seeping past the valve.

Is there any good way to identify cracks without taking it to a machine shop? They are spendy here.

 

[napabavarian]

Perhaps I should ask where they cracking so I can look there

 

[davedj1]

I think I would take it to a machine shop and have them magnaflux it. I wonder if your valves just needed adjusting? Look around the valve and seats.

 

[napabavarian]

I ordered a valve spring tool so I'll remove them when I get a chance, being a top exhaust I wondered if some water got in there and pitted the valves? I'll know soon.