Hello All,
I may be a little verbose but I’d like to get all the info across, so bear with me. I’ll try to break it up so’s it’s easily readable.
I’m new to this type of discussion and information gathering, but I need some help. I’m a fair mechanic and understand the terminology, but I can’t seem to find a suitable answer from Kubota or these forums and the dealer wants too much just to look at it. I hope you guys can steer me in the right direction.
I’ve got a B7100 HST 4wd that I bought new in 1992(3) which now has about 2800 hours. I’ve used it mainly to cut grass on my 5.5 acre lot. I started with a 4’ bush hog and now use a 5’ Land Pride finishing mower. I have a 4’ blade that I push stuff around with. I’ve also used it to rototill a small garden and of course remove what little snow we get here in Kentucky. I’ve even added an FEL to it. It ran great and I’ve kept it up. (garage kept, oil & filter changes, greased,etc., I even added an oil pressure, temperature and amp gauges to it years ago. Don’t like “dummy” lights or whistles: too late when you notice them). Normal for this tractor when running wide open, was 45-50psi, 200-210 degrees and would pull and operate fine.
Now… about four years ago, 2010-2011, the little guy picked up a bad rattle when ever the clutch was disengaged and re-engaged. The local dealer told me that it was a bushing that had worn out for the drive shaft to the rear components (PTO, Transmission), and was allowing the universals and shaft to not rotate true, hitting the casings. …OK… I let them have it to repair. They had a time getting the parts needed and so it got way into the mowing season that spring; so I went and purchased a Kubota ZD326 to cut grass.(love it) Seven weeks later I got the B7100 home. Didn’t need it much (had the ZD) so I just parked it in the garage.
That winter I used the tractor with blade to push a little snow and noticed that it started overheating and what looked like to me way too much blow by from the PCV pipe. It started dripping oil from the PCV pipe as well!! It never did that. Oil pressure dropped to 15-20lbs; water temp climbed to 240 before I noticed it, again it never ran like this. I shut it down and waited a while and restarted and finished the job. But it never operated this way.
Thinking something may be blocking the coolant, I removed the hoses and radiator; drained the coolant; back flushed the radiator and engine (ran clear); changed the oil and filter; cleared the radiator core; tightened the belt and restarted.
Didn't help... Now it runs hot with excessive blow by and the exhaust doesn’t smell right. The exhaust is pretty clear and colored black, but if you goose it, it will get some white smoke. As it gets hot the exhaust will clear completely. It also seems to be weak. When idling, (so I can hear it) it picked up a whine in the rear section that was not there before and the hydrostatics don’t stop the tractor when the pedals are released; keeps moving slowly then stops. Press the clutch or move the hi-low range to neutral and the whine stops. Oil pressure after start is 50-55 lbs, then slowly drops as the engine warms up to about 40-45 then holds. Although when running hard the pressure while climb back to about 55-60. Starts fine, idles fine, but the water temp climbs fast, will get to 180-190 in 10 minutes or so.
So I took it all apart and cleared it all again. I left the upper hose off and started the engine with water in the block and goosed the engine to see if any bubbles came through the coolant indicating a blown head gasket: nothing. Don't know.
If you operate hard for more than 20 minutes, the exhaust will clear completely, the blow by gets heavier and the temp climbs rapidly (230-240) and oil pressure down to 25. It seems to me that some thing is blown in the engine itself. I knew about all the radiator plugging and such and have kept all that clean and clear, new belt, 50/50 mix, etc. I don’t think the dealer’s mechanics did anything to it, they’ve got a very good reputation, very helpful. But you never know…the whine tells me something they did ain’t right, but too late to complain now. Can you guys help me out? Got any ideas?
Thanks,
JoeM
I may be a little verbose but I’d like to get all the info across, so bear with me. I’ll try to break it up so’s it’s easily readable.
I’m new to this type of discussion and information gathering, but I need some help. I’m a fair mechanic and understand the terminology, but I can’t seem to find a suitable answer from Kubota or these forums and the dealer wants too much just to look at it. I hope you guys can steer me in the right direction.
I’ve got a B7100 HST 4wd that I bought new in 1992(3) which now has about 2800 hours. I’ve used it mainly to cut grass on my 5.5 acre lot. I started with a 4’ bush hog and now use a 5’ Land Pride finishing mower. I have a 4’ blade that I push stuff around with. I’ve also used it to rototill a small garden and of course remove what little snow we get here in Kentucky. I’ve even added an FEL to it. It ran great and I’ve kept it up. (garage kept, oil & filter changes, greased,etc., I even added an oil pressure, temperature and amp gauges to it years ago. Don’t like “dummy” lights or whistles: too late when you notice them). Normal for this tractor when running wide open, was 45-50psi, 200-210 degrees and would pull and operate fine.
Now… about four years ago, 2010-2011, the little guy picked up a bad rattle when ever the clutch was disengaged and re-engaged. The local dealer told me that it was a bushing that had worn out for the drive shaft to the rear components (PTO, Transmission), and was allowing the universals and shaft to not rotate true, hitting the casings. …OK… I let them have it to repair. They had a time getting the parts needed and so it got way into the mowing season that spring; so I went and purchased a Kubota ZD326 to cut grass.(love it) Seven weeks later I got the B7100 home. Didn’t need it much (had the ZD) so I just parked it in the garage.
That winter I used the tractor with blade to push a little snow and noticed that it started overheating and what looked like to me way too much blow by from the PCV pipe. It started dripping oil from the PCV pipe as well!! It never did that. Oil pressure dropped to 15-20lbs; water temp climbed to 240 before I noticed it, again it never ran like this. I shut it down and waited a while and restarted and finished the job. But it never operated this way.
Thinking something may be blocking the coolant, I removed the hoses and radiator; drained the coolant; back flushed the radiator and engine (ran clear); changed the oil and filter; cleared the radiator core; tightened the belt and restarted.
Didn't help... Now it runs hot with excessive blow by and the exhaust doesn’t smell right. The exhaust is pretty clear and colored black, but if you goose it, it will get some white smoke. As it gets hot the exhaust will clear completely. It also seems to be weak. When idling, (so I can hear it) it picked up a whine in the rear section that was not there before and the hydrostatics don’t stop the tractor when the pedals are released; keeps moving slowly then stops. Press the clutch or move the hi-low range to neutral and the whine stops. Oil pressure after start is 50-55 lbs, then slowly drops as the engine warms up to about 40-45 then holds. Although when running hard the pressure while climb back to about 55-60. Starts fine, idles fine, but the water temp climbs fast, will get to 180-190 in 10 minutes or so.
So I took it all apart and cleared it all again. I left the upper hose off and started the engine with water in the block and goosed the engine to see if any bubbles came through the coolant indicating a blown head gasket: nothing. Don't know.
If you operate hard for more than 20 minutes, the exhaust will clear completely, the blow by gets heavier and the temp climbs rapidly (230-240) and oil pressure down to 25. It seems to me that some thing is blown in the engine itself. I knew about all the radiator plugging and such and have kept all that clean and clear, new belt, 50/50 mix, etc. I don’t think the dealer’s mechanics did anything to it, they’ve got a very good reputation, very helpful. But you never know…the whine tells me something they did ain’t right, but too late to complain now. Can you guys help me out? Got any ideas?
Thanks,
JoeM
