FE350 keeps breaking counterweight shafts

[ToyotaGuy93]

Hello all,
For the last few months I have been reading up on this website whenever I come across an issue for the carts I have at my work. Although I have only had to do this a few times, I must admit that the suggestions to certain problems have been very helpful with troubleshooting some of the carts that I work on day to day.
First off, this is my first full year of working on any kind of golf cart, so I have been pretty much learning as I go. I used to work on helicopters in the Army, and before that I have had plenty of experience in the automotive and diesel industry. The familiarity of engines is known, but they aren't all the same. My father for the last year has been serving on a deployment alongside my younger brother, (kinda felt left out as it would have been my 3rd tour) and while he has been gone I have taken over his position at a local golf course as their equipment maintenance technician. Although I work here, I haven't really had to work on the carts too much, because they do not break down often; which leaves me time to work on a lot of the diesel tractors and other agricultural machinery we use on a daily basis.
So the issue I am having is one of our service carts (a 2004 Carryall 2, FE350 non-acr engine, pedal start; first made a huge clacking noise. I knew right away it was most likely coming from the bottom end. (these carts have extensive hours on them, as much as 3000+) I removed the engine and began to break it down. Upon inspection of the crankshaft and cam gear, I discovered that the counterweight had been tossed aside. The connecting pins to the connecting rod had come out of its position, as well as breaking the counterweight shaft. I ordered a new counterweight, (took 3 weeks from Kawasaki because they were on backorder) as well as a new counterweight shaft and reinstalled everything. I took my time inserting the parts back into the motor, ensuring not to force anything into it or to take any shortcuts. After I resealed the engine and reinstalled it into the cart, it ran perfectly fine for the next three or four days after it was used by the crew. On the fifth day, the motor made an ungodly noise and broke. So once again, I removed the engine and tore it all down. Tearing the engine down wasn't the annoying issue, it was just nuisance of removing it all over and reinstalling it. Good thing these motors don't weigh much, haha.
So after I took it all apart, I expected to see the same issue and it turns out that only the counterweight shaft (which seems to be made of aluminum) had snapped, knocking the counterweight from its location. I ordered two more shafts and reinstalled one in it. I just tested the cart this morning and it seems to run perfectly fine all over.
My question is this: Although a part could be defective from the factory, what would possibly keep causing that shaft to break over and over? Spinning the crank by hand renders no internal parts hitting the counterweight or anything else, but that's only rotating it by hand. I noticed that when I first installed the new counterweight, that both connecting rods from the counterweight to the crankshaft seemed to have some play in them. I have seen a few other engines torn down from these carts and they seem to not have any issues when they had play in their connecting rods. Are there lobes on the crankshaft that the connecting rods sit on or are they not supposed to move at all?
Again, any sort of advice would be greatly appreciated. As stated before, I do have mechanical history and am mechanically inclined enough as to completely strip something down and rebuild it, they just don't install fe350's on Uh-60's. Thanks.

[tpg]

Your counterweight arms have wear in the bushing area that rides on the crankshaft. The arm has a bushing in it. Some times the crank is really worn on this spot and needs replaced. You need 0 movement in this area. Your arms are moving so much that they are snapping the counterweight shaft.

[ToyotaGuy93]

TPG,

thank you for the tip!

turns out that when I had pulled the engine and cracked it apart again to peek inside, the worn connecting rod had snapped. I went ahead and bought 2 of them so I could just have peace of mind and know they are both new. ive spent about an hour taking the engine completely apart, and the last thing I have left to do is to seperate the metal cam gear from the crankshaft. any suggestions as to go about this without damaging that metal gear?

[tpg]

Best way is to apply a little heat to the gear and pry underneath to pop it off. then check the crank for wear. Courses that didn't change oil regularly have this problem. Dirty oil is like sand in an engine.