7100 Rebuild

ar963 · Mar 18, 2009

Hello,

My 7100 had been spewing white smoke since I bought it two years ago. I knew that the rings were probably worn. Well now it doesn't start and I am only surprised that it gave me two years. I am so impressed with this little mule that I want to replace the rings and any other parts that might be worn. I am mechanically inclined but have never rebuilt an engine bigger than 1 cylinder Briggs & Strattons. I basically want to know how hard of a job this is and wether I should get a manual for the torques. Here is a pic of the engine after removing some of the sheet metal and accesories. Any advice would be greatly appreciated.

rbargeron · Mar 18, 2009

White smoke could be coolant getting into a cylinder. Does it keep smoking after warming up? Does the cooling system burp out? I'd take off just the head at first to have a look at the gasket and cylinder condition.

ar963 · Mar 18, 2009

Thanks, It does keep smoking after warm up. I am sure its the ring because the person I bought it from had an estimate from the Kubota dealer for a ring replacement. He just decided to get a new one.

ar963 · Mar 24, 2009

It's a goner! I pulled the head and found the middle cylinder missing a small chunk and the head all pitted. Now I have to decide wether to try and find a used engine.

ibnxe · Mar 25, 2009

From the pictures, I would say that it looks like some substantial etching has occurred. The most likely culprit would be a slow water leak into the combustion space. The area at the top of the cylinder doesn稚 look too bad, and as long as it doesn稚 compromise the gasket sealing, would probably be OK. On the other hand, the head will most likely need replacement, as well as the piston in that cylinder.
A new or rebuilt engine might be the best bet. It all boils down to cost. What you have there could be resurrected for less that the cost of a replacement.

jas67 · Mar 25, 2009

From what I've seen on the price that people want for used small diesel engines (excluding some of the Chinese single-cylinder ones), you might do better just buying another B7100 that might have some other need, and combining the two, or even just buying a complete one, and sell yours a fixer-upper. Just don't be so set on fixing yours that you miss what might be a lesser expensive alternative. You might even find a good runner for the cost of an engine, and then you'll have lots of spare parts. If you don't yet have a front end loader, and want one, then that is another reason to buy another tractor, as FEL's for these older tractors are not often available separately, unless someone is parting-out a dead tractor.

Please accept my condolences for your loss, as these B7100's are great machines (yes, I'm partial, I'm on my 2nd).

charlz · Mar 25, 2009

How many hours on that engine? I think the downside to these tractors is that it is the engine that eventually gives out... so not many of them around.

amitysanimal · Mar 25, 2009

On my B7100 it had a bad rod bearing when I bought it. I also had another engine that had thrown a rod. I thought between the 2 engines I could build one good running engine. I was told it would be too expensive to fix, the gasket kit alone was over $350.00. I lucked out and found a used motor for $800.00 and put that in. So now I have 2 parts engines and one great running engine.

rpraymond · Mar 26, 2009

As far as rebuilding your engine, you have to figure what it will cost compared to the condition of the rest of the machine. You can find a used engine but if your machine is in really nice shape and you plan to keep it a fresh engine will last you for the life of ownership. If you are reasonably mechanical and follow the workshop manual you should, with the help of a good machine shop, be able to rebuild yours. Plus you'll get the satisfaction every time you use it of your expert mechanical skills.

Just my opinion.
Good luck and I hope it works out.