4200 engine rebuild

[mbis]

What was wrong with it that you rebuilt it

 

[dfkrug]

Parts for my 4300 were around $750, machine shop charged $300 and they magnafluxed the head, ground the valves and seats, replaced valve seals, shotblasted and cleaned the head, bored+honed the block, replaced the cam bearings, cork polished the crank and measured it, replaced all the freeze plugs and cleaned the block, replaced the wrist pin pushers and honed to fit, then wrapped everything in shipping plastic. They didn't surface the top of the block, which I would recommend having done because of the way this engine is made after what I went through.

You had the machine shop do a lot. My last JD engine rebuild was maybe half that for machine work. Since
there is no .020" piston made, I was fortunate in that .010 cleaned up (barely) the wear I had from air
filtration failure. I did not change any bearing inserts on crank or cam as they were still in spec. You
can sleeve this engine, but that's a bunch more.

As for parts, I only bought piston/ring sets, a headgasket, and valve stem seals. Less than $500 for all that.

Most tractor shops do not want to do engine rebuilds. Just splitting a tractor starts at $1K or so for labor.

 

[TimberHole]

Overheating. No water coming from anywhere charged t-stat, head gasket. No cracks that can be seen

When you had the head off did you have it checked for cracks? You didn't mention the water pump or radiator? What have you done there? With regard to overhaul, how is the compression and oil pressure? So far I haven't heard anything that indicates it needs overhauled.

I bought a tractor with an overheating issue and they had already done the head gasket. The problem ended up being an improperly installed head gasket. Just because the head gasket was done doesn't mean it was done correctly.

 

[mbis]

When you had the head off did you have it checked for cracks? You didn't mention the water pump or radiator? What have you done there? With regard to overhaul, how is the compression and oil pressure? So far I haven't heard anything that indicates it needs overhauled.

I bought a tractor with an overheating issue and they had already done the head gasket. The problem ended up being an improperly installed head gasket. Just because the head gasket was done doesn't mean it was done correctly.

Don't know about oil pressure and radiator is ok. Don't know how to check oil pressure I am not a mechanic, although I know the head gasket was put on right

 

[larboc]

What was wrong with it that you rebuilt it

It was a broken piston from overuse of ether due to not knowing about the thermistor issue for me. The bores weren't bad and I could have gotten away with just putting in a new piston, but by the time I was into it that far I went ahead and rebuilt the whole engine. Tractor has to be split to replace a piston anyway. liquid cooled yanmars will last a VERY long time if they aren't abused.

 

[mbis]

It was a broken piston from overuse of ether due to not knowing about the thermistor issue for me. The bores weren't bad and I could have gotten away with just putting in a new piston, but by the time I was into it that far I went ahead and rebuilt the whole engine. Tractor has to be split to replace a piston anyway. liquid cooled yanmars will last a VERY long time if they aren't abused.

Well didn't abuse it. Just one day the temp gauge went to red.

 

[TimberHole]

Did it smell hot? Could just be a sensor but probably not. Nothing you've said indicates to me that it needs an overhaul. In my limited experience most overheating issues on the little Yanmar's are head or head gasket issues. The head probably should have been checked while it was off. If you're not a mechanic I recommend finding a local mechanic familiar with the little Yanmar's and let him diagnose.

 

[mbis]

Did it smell hot? Could just be a sensor but probably not. Nothing you've said indicates to me that it needs an overhaul. In my limited experience most overheating issues on the little Yanmar's are head or head gasket issues. The head probably should have been checked while it was off. If you're not a mechanic I recommend finding a local mechanic familiar with the little Yanmar's and let him diagnose.

No I changed the sensor, t-stat and water pump is good

 

[deserteagle71]

Rebuilt my 4300 last year it ended costing me around 2000 , but I am in the process of changing out the head gasket again. Now as far as JD they charged me 1200 to tear it down the first time but not remove it from tractor. That did include towing. To rebuild the engine they wanted around 16,000 yes that is not a typo.I ended getting a rebuild kit from Maxine force.

That sounds about right, from John Deere! Last October I called a John Deere dealer up in Idaho about having the engine in my 2020 diesel rebuilt...the service manager told me it would run $15,000 - $20,000 depending on what they had to do. This for a tractor I paid only $7,000 for, 21 years ago!

 

[larboc]

Well didn't abuse it. Just one day the temp gauge went to red.

Did coolant spill out? Will it cool off if you bring it back to idle? Have you check for bubbles in the radiator cap at idle? Fan belt tight? Inspected the waterpump to make sure something isn't screwed up with the vanes?

When the headgasket went on mine (long story) I was smelling coolant blowing out the reservoir bottle while working it hard with a flail mower a long time before the temp gauge started moving.