UR 3 engine!!

[Ola]

Hello !! I am from Norway. And i am a Zetorowner. Just a few weeks ago i came across a 7540 without turbo, 71 hp (2500 engine hours) and it became mine. I can see now that the engine swallows too much oil I have two UR 1 tractors both of them is ok (2900-3000 hours) The engine on the 7540 is reaching 80-85 C very soon. The oil is black after short time. Noisy. Is this normal for an UR 3 engine ? Sorry about my writingskills

 

[Renze]

Hmm.... I think you need some new piston rings. The oil gets black because hot combustion gasses are getting over it, that escape through the piston rings. This also causes the quick temperature rise...
overhauling engines, not every smith can do that, but some tweakers do that job very well. depends more on experience than the capital of their machinery.

buy a set of piston rings and before installing them, grind the area with a piece of sand paper, with fine grid. This is to let the surfaces "wear into" each other, to achieve proper sealing.



Oh yes, when you have the crankcase open, be sure to check the crankshaft bearings... You'll be sorry if you need to open the crankcase again.... Just routine.

 

[pter]

hi
when you are replacing the piston rings be sure you clean out the groves properly use one of the old rings grind the face off the ring till sharp when sharp it will quickly remove the carbon build up. use a piece off cloth to hold the ring as they y can cut you ??????? also if there is much wear on the piston bores.get a set of rings (top ring ) with a champhered edge. this will stop new ring breaking aginst the wear ledge . if you cannot get them you cab chamfer the ring yourself .it easy to do

 

[treaney]

Given that the tractor only has 2500 hours on it - if the hours are correct - this seems very little to have ring trouble. Could the problem be due to the tractor operating for long periods at tickover? It would be worth subjecting the tractor to some hard work e.g. rotavating to remove build up and deposits before fitting new rings. That's what I would try anyway.

Tom

 

[Renze]

Yes, it's worth a try... turn her open to 85 hp and hook up some heavy tillage implement... it could cure her cheap...

 

[Ola]

Thanks everyoneI have not been able too use the internet for a few days, but now the phone is ok. I am going too look at the pistonrings and change them In the mail i have received a workshopmanual (hm...interesting...)69) Regarding the fuelpump: It was earlier mounted a pump who was adjusted to ca 85 HP. But now i think it is an original one (lazy) Is it possible for the sylinders to be too hard ? I now that the earlier Valmet engines is having this problem. Are they getting hard because of the rough use ? Ola.

 

[Renze]

Piston rings wear because of temperature: working too hard with a cold engine (just started and directly put to heay work) or overheated engine that is put out before it could cool down a little.

Hard work is absolutely no problem. We have a 1976 6718, 9930 hours on it. I worked with a frase designed for 140 hp at full depth, while this engine hardly consumes any oil...

Engines wear is caused by temperature: Too cold or too hot. Check water, oil and temperature, and it will last long, even in very hard work.

 

[treaney]

What Renze points out is good operating practice - get the engine to its operating temperature before operating it hard.

The other key items for engine wear that are often overlooked are:

1. Oil[/] - high quality, CLEAN oil to provide the neccessary lubrication. Idealy hydrodynamic[/] lubrication where there is no metal to metal contact and consequently no wear. In practice however, lubrication is boundary [/]where the oil seperating the moving parts is incomplete. The quality of the oil and how clean it is are critical.

2. Air filter [/]- CLEAN air is critical to engine life - imagine what a hard dust particle that doen't get burned can do to your cylinder walls.

Tom

 

[woodbeef]

You know Tom,I think you've hit on something that seems so hard for most people to fully understand the ramifications of. That hard dust particle that is so small and unassuming is overlooked as being dangerous by way to many tractor owners. Yes most people know enough to change the oil and filters,but the air cleaner is often a very different story I find when looking at used tractors. Sometimes they might be new,but were just thrown in the canister,as is witnessed by the dust trails,or missing gaskets/O-rings,and or hold down plates and nuts.

 

[OLA]

About my bad pistonrings: If i do not change them and i start driving the 7540 the same way as my 6011 (easy start, not more than max 1500 rpm with cold engine) is this going to change the pistonrings in any way ????

 

[kenjar]

Hey Ola,

If you do decide to tear down the engine, I would check the sleeves for wear. New piston rings will not last very long if the liners are worn.

Hopefully giving the 7540 a good work out will "reseat" the present rings.

 

[OLA]

Hello ! Yes i am going to check the sleews for wear (and the crankcase). I think the engine has been driven too hard and i can see that the waterpump is brand new......hot ? I have seen carmecanics put a little water into the engine when it is still running. This is to remove buildup. Is it possible to do this on a dieselengine, or is it too dangerous ? Anybody else who is driving UR 3 tractor ? What should I be aware of ? The UR3 engine is a bit more noisy than the UR2, is it because of the knocker in the fuelpump ?

 

[Renze]

OLA : Being careful with a cold engine is a preventive measurement, not a cure... It's an anti-flu vaccin, not the antibiotics....

Your story is like mine: an engine getting too hot, with a new water pump !!

Our 5245 was perviously owned by an old man, who probably thought his tractor was taking a piss, just like the horse he had, and after the freeing piss it could start working better than before.... Sure NOT !!!>

Oh yes, take out the fuel nozzles and let them be tested !!
My 5245 also (probably) has two very bad fuel nozzles. A guy that worked at a marine engine shop, told me that a worn (or burned) fuel nozzle could spit the fuel against the cylinder wall instead of dispensing it, causing piston ring leaks. Piston rings could be in good shape, but the fuel spit on the cylinder wall causes the very, very little amount of oil on it to dissolve, causing the piston rings to leak.

let it run stationary, and tightly grip an injector line with two fingers. If they are o.k you will feel short, intense pulses through the line every time a dose is injected. a worn injector just flaps...

If they are o.k you will feel it in the muscles of your hand within a minute. (160 bar in milliseconds, a very intense frequency)

 

[OLA]

Hey ! Thank you. You are into something here. An adjusted fuelpump up to a not original level, A man who is driving a bit over max all the time. And a tractor without any oilcooler. It makes sense. I want to tell you a story about a 6711. This was in 1982-83. This tractor (not ours) was used in a original way. Maybe it was something wrong with the fuelpump on this tractor, I dont now. In the spring the 6711 was stationary in of a front of a pump (fertilizer) and the pump was maybe a bit too big. The owner had a metod of giving the engine a bit extra, he pushed the coldstartbutton when the trottle was at maximum. If you passed the farm in the evening you could see the exhaustsystem was glowing in the dark 69). Can you imagine. The tractor is still alive belive it or not. The injektors was finito. And the engine was running on two or three sylinders. But the zetor factory mecanics was making it OK each summer (for free, we paid only for the parts) OLA

 

[Renze]

Yes, our 5718 sometimes had a little flame on the pipe, like a jet engine.. blue/yellow, looked beautiful..

Using the cold start button is bad for your engine, it does not just inject more fuel , but injects earlier, giving some bad bangers on your pistons and drivework.

He would be better off when he'd adjusted the fuel pump the official way, instead of using the cold stat button. Tuning by the official way, adjusting the helix twist, is no problem. The cold start button adjusts the combustion characteristics like temperature and timing, giving much smoke and little power.

 

[zetor er best]

hei
7540'n er ikke kjent for og ha en god motor, invester i en 96/10641.

hilsen ifra akershus


Hello !! I am from Norway. And i am a Zetorowner. Just a few weeks ago i came across a 7540 without turbo, 71 hp (2500 engine hours) and it became mine. I can see now that the engine swallows too much oil I have two UR 1 tractors both of them is ok (2900-3000 hours) The engine on the 7540 is reaching 80-85 C very soon. The oil is black after short time. Noisy. Is this normal for an UR 3 engine ? Sorry about my writingskills
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