Another Kawasaki with a Failed Camshaft

[Skywatcher]

Greetings All

Just finished a camshaft replacement in a Kawasaki FD620D V-twin on a Cub Cadet 2086 tractor. On this one, the swages broke off the 3 rivets, the rivets backed out and the gear slipped on the shaft. 2 out of the 3 rivets had been pulled into the oil pick-up tube and were sitting against the strainer screen, no damage to pump or engine internals. Was able to replace the camshaft without having to remove engine from tractor, just dismantle front end of tractor and rock engine back a few degrees, just enough to get crankcase cover off. Interestingly enough, the composite gear is completely un-damaged, just separated from the shaft, but I replaced it with the one piece cast steel shaft which will not fall to pieces.

On these camshafts, I've seen the holes in the cam gear elongate and turn into slots and I've seen a section of teeth break off the gear, but this is the first one that I've seen where the rivets simply fell out. 400 hours seems to be the life expectancy of these composite gear camshafts in my experience. Any thoughts or comments to add to this? All the best,

Sky

[KE4AVB]

A good question. I got a FD590V-BS04 is in the shop that has apparent camshaft failure too. The customer wasn't will spend the needed funds to repair the JD 345 mower as it had deck and pto problem too. It just sitting there awaiting for me to make up my mind to tear it apart or not. I have been told it came with a plastic camshaft setup too but when I look-up the replacement camshaft it is all metal.

[Luffydog]

Some of those will fool if the valves get stuck in the guides will mislead to think that's it's the cam.

[Skywatcher]

Hi KE4

Although I haven't heard or read anything official, I wouldn't be surprised if Kawasaki no longer supplies the quiet camshaft with the riveted composite gear as they are just too prone to failure. Along the same idea as the front axle on MTD lawn tractors. The tractors come from the factory with a cheap pressed steel axle which wears through at the pivot point, but the replacement axle supplied through parts is cast iron. Build them as cheap as possible, then charge lots for replacement parts.

If you do split this engine to replace the camshaft, remember to order the two O-rings that go in the oil galleries between the crankcase and the crankcase cover. I believe these engines have the camshaft driven fuel pump in behind the governor plate, so order a new fuel pump mounting gasket too. The Cub Cadet I just worked on has the electric fuel pump under the fender deck, so no fuel pump on the engine. The camshaft didn't even have the fuel pump drive cam lobe machined, just a ring of rough cast steel. Here's where one would need to make sure you get the correct camshaft for the engine you're repairing. No need to dismantle the water pump as this comes off complete with the cover. That being said, if you are concerned about possible coolant leakage after the repair, replace the water pump gaskets while the engine is out, on the bench and in pieces, there'll be no easier time. All the best,

Sky

[Skywatcher]

Hi Luffy

Indeed I have seen these engines with stuck intake valves when the engine was run on very stale gasoline, the varnish condenses out of the fuel and accumulates on the valve stem sticking the valve. This will usually lead to a valve stuck open or a bent push rod because the valve was stuck closed. Either way, a little further diagnostic testing will tell you if it's the camshaft or just the valves. Pop the pushrods out of the rockers, remove the sparkplug and drop a wooden dowel or a chopstick down into the cylinder as a piston position indicator (PPI). Put one finger on the end of each pushrod, rotate the engine by hand, feel what the pushrods are doing and watch the PPI. This will give you a very good idea as to whether the camshaft is in time with the crankshaft or not. All the best,

Sky

[KE4AVB]

Coolant leakage was one of the complaints when it came in so gaskets are already here. And just makes sense to replace the o-rings you mention as that engine hasn't been apart in 20 yrs.

Just spending the day repainring a ASW UTV. Needed drive shaft CV boots and a drive belt besides the annual maintenance. Glad I didn't install the drive shaft before replacing the belt as I would had to remove it again just to move the engine to the right side.

Hi KE4

Although I haven't heard or read anything official, I wouldn't be surprised if Kawasaki no longer supplies the quiet camshaft with the riveted composite gear as they are just too prone to failure. Along the same idea as the front axle on MTD lawn tractors. The tractors come from the factory with a cheap pressed steel axle which wears through at the pivot point, but the replacement axle supplied through parts is cast iron. Build them as cheap as possible, then charge lots for replacement parts.

If you do split this engine to replace the camshaft, remember to order the two O-rings that go in the oil galleries between the crankcase and the crankcase cover. I believe these engines have the camshaft driven fuel pump in behind the governor plate, so order a new fuel pump mounting gasket too. The Cub Cadet I just worked on has the electric fuel pump under the fender deck, so no fuel pump on the engine. The camshaft didn't even have the fuel pump drive cam lobe machined, just a ring of rough cast steel. Here's where one would need to make sure you get the correct camshaft for the engine you're repairing. No need to dismantle the water pump as this comes off complete with the cover. That being said, if you are concerned about possible coolant leakage after the repair, replace the water pump gaskets while the engine is out, on the bench and in pieces, there'll be no easier time. All the best,

Sky

[38racing]

funny. When my friend got rid of his john deere and bought an husqvarna he insisted on getting it with a kawasaki because other brands had a plastic cam.