B1550

Anonymous Poster · Oct 5, 2002

I just purchased a B1550 and noticed a small amount of smoke comming from the breater tube that exits out on the left side of the tractor. It may be more of a mist than anything and not smoke at all, hard to tell. Is this normal or is this a sign of a pending engne problem????

Carl_NH · Oct 7, 2002

JB,

I believe this to be normal as my old L185 did this with 900 hrs and the new B21 mists a bit from the breather tube as well. Typically at idle I will notice this - not a lot at operating speeds though.

Carl

Kelvin · Oct 7, 2002

I guess it depends on how heavy the smoke is.

The Bad News:

My late 1970s gear drive B7100 did that when I bought it. Then the light smoke turned to heavy smoke. Then very heavy smoke. Then oil drops came with the smoke. Then oil came pouring out.

It turns out that 2 out of 3 cylinders had compression rings go bad. I believe that this was caused by engine overheating which resulted from the previous owner's lack of knowledge of thermo-siphon cooling systems (no water pump; no thermostat). Overheat conditions can rapidly occur when using more than a 50/50 mix of antifreeze/water in a thermo-siphon cooling system.

The Good News:

I think that the B1550/B1750/B2150 series tractors used normal cooling system designs that included water pumps and thermostats, resulting in less sensitivity to antifreeze mix. So hopefully your tractor hasn't been overheated and the "blow-by" will remain a light mist.

Kelvin

Anonymous Poster · Oct 8, 2002

Well this mist is comming from the breather tube not the exhaust. The tractor seems to have plenty of power though and the engine is staying cool. I was just woried that I might be looking at an impending doom. Does anyone know the price to get the engine overhauled??

Thaanks for all replies.

JB

Kelvin · Oct 9, 2002

Well this mist is comming from the breather tube not the exhaust. 

Somehow, I must have mis-communicated. All my discussions were based upon "blow-by" or "mist" coming out of the breather tube that comes out of the top of the valve cover.

As I understand it, this "blow-by" is caused by leakage around the compression rings which allows the pressure in the cylinder to escape into the bottom of the engine, then up through the oil channels into the valve cover and out the breather tube. In my case, the "blow-by" was really excessive and pressurized the lower half of the engine such that the oil was forced back up into the valve cover and out the breather tube. The last time I started it (prior to disassembly) it poured at least a pint, maybe even a whole quart, out on the ground in about 2 minutes of idle operation before I noticed it and shut down the engine.

Does anyone know the price to get the engine overhauled??
It depends upon how much you want rebuilt. The good news is that the engine parts are generally available (while entire engine assemblies are probably not available). I had someone do a partial rebuild on my B7100's engine. We left the engine in the tractor and pulled the head and pistons. All components were in excellent condition. I don't have my receipts readily available, but it seems that I spent around $500-$600 on parts (rings, rod bearings, valve guides & seals, gasket set, etc.) and rebuilding the head. I think that I spent about $1000 total including the labor. I reused all of the major parts (pistons, rods, crankshaft and crankshaft bearings).

Kelvin

larso1 · Oct 12, 2002

Hi Kelvin et al,

What you describe is the same thing that's happening with my Iseki two cylinder tractor (TS1610F), unfortunately. It starts and runs fine for about 5-minutes, no smoke from the exhaust, and then starts puking out oil through the vented oil fill cap on top of the valve cover. When I immediately unscrew the dipstick to check oil level, I find it's pressurized and starts flowing out there too. Then it settles back to normal level. The only crank case vent I can see is a 1/8" steel tube that connects from the block up to the top of the head. I pulled it and checked for obstructions, but it was clear. Guess I need to do a compression check too, and probably end up pulling the head like you did;-( Do you agree?? I would hope I could do this with the motor in the tractor as well.

Bill

Kelvin · Oct 13, 2002

Re: B1550 - Diesel Mechanics?

Guess I need to do a compression check too, and probably end up pulling the head like you did;-( Do you agree?? 

A compression check will certainly answer any questions regarding the status of compression rings ... if you can perform the test or find someone to do it for you. There are several experienced diesel mechanics that visit this board that can give a better qualified response than I can.

Lesson Learned: I could not find anyone convienent to perform the check for me. [I may be wrong here, but it seems like I asked my local Kubota dealer (among other mechanics) about checking the compression for me and I think I remember them saying they didn't have the diesel compression test tool either.] I initially couldn't find the "psi" ratings for the cylinders, so I attempted to do a compression check using an automotive pressure guage with the intent of comparing the relative readings to look for a sign of trouble. I checked the first two cylinders and they were comparible (good so far...). The pressure gage didn't seem to work on the 3rd cylinder, and after this attempted test it no longer worked on any cylinder. It turns out that the 1st two cylinders were the ones that had bad compression rings (which brought their pressure down into the range of an automotive pressure gage) but the 3rd cylinder was in good shape (compression about 200 psi or 300 psi higher than the 1st two) and it destroyed the compression tester. At the cost of an automotive compression tester, I discovered my problem.

Good Luck,
Kelvin