17hp twin cylinder FH500V, play in the crankshaft

[arch252]

I'm working on a LX277 with a twin cylinder FH500V, 17 hp air cooled. It did not have a starter. I bought a starter and installed it and noticed the flywheel teeth were resting on the starter teeth, they couldn't disengage. This is a side mount starter, not a top mount so the there was no way that it was just a spacing issue, the bolt pattern for the starter was fixed. I started the engine and it ran nice and smooth, no smoke at all. The starter could not disengage so it grinded like all heck so I had to stop the engine after only 3 or 4 seconds. The flywheel rests on the cone shaped top of the crankshaft so there was no spacing that either. I notice some up and down play in the crankshaft, A LOT of up and down play. I could raise the crankshaft a full 5mm (about 1/4"). With the crankshaft raised the flywheel easily cleared the teeth of the starter.

Obviously I am thinking the worst. How else could the crankshaft have dropped that much unless it has worn down into the bottom bearing of the short block? There was no metal in the oil when I changed it. The engine turns over and spins very smoothly. Very good compression. No oil leaks at all, not from the top or bottom oil seals or anywhere else. How could the connecting rods not get in a bind with the shaft moving that much? Is there a simple explanation to this that I have overlooked or do I have to take the engine off, open it up and inspect it?

 

[bertsmobile1]

Been through all of the Kawakasi service information that I have here and there is no specification for end float but 1/4" sounds way too much .
Briggs allow .002" to .030" of end float on their V twins with no bearings.
Kawakasi are generally a lot tighter than Briggs so .250 " is massive.
Looked through the parts breakdown and there is no thrust washers so it looks like the crank shoulder sits directly on the crankshaft boss.
Not much help I know.
What is the history of the engine ?
How thick is the crank case gasket ?

 

[arch252]

I have no history on it, the engine was supposedly good and the transmission bad but you know how that goes. Not sure on the thickness of the case but I can't imagine it's much more than that. I'm sure the area where the crabkshaft sits is much thicker. Sounds like this is the same design that's caused all the trouble with the Kohler Courage engines. I guess I'm going to have to open it up and inspect it. I just find it hard to believe there has been that much wear with no metal residue in the oil.

 

[bertsmobile1]

Problem with the courages was they started as the command which is a excellent engine then it was down graded to make it cheap enough for domestic ride ons
And yes the case has a boss that the crankshaft runs in.
I would have thought that Kawakasi would have fitted a ball race top or bottom to regulate end float but it is a plain , pressed in bush on the top and runs directly on the lower case which runs under oil so gets little wear.

 

[arch252]

So can you think of anything that would cause 1/4" drop (and up and down play) in the crankshaft? Does it make sense that the operation of the crankshaft is still smooth and not binding? I was really hoping there might be some other explanation but this isn't looking good at all.

 

[bertsmobile1]

Other than being rebuilt with the wrong crank, no.

 

[arch252]

Thanks Bert, looks like I'll be breaking down another one, these Kawasaki's have put the hurt on me lately.

 

[arch252]

Solved the mystery of the excessive play in the crankshaft. It's not good. As you can see in the pictures the crank has eaten down about of 1/4" of the crank cover. There is an extra deep groove where the snap ring wore it down even further. So....anybody have an old crank cover for a FH500V laying around? Looks like a new one is about $128 and a used one on EBay is about $50 shipped. I can probably pick one up for $30 to $50 but is it worth it? The crank looked good to me and I did not see any other internal damage but I can't imagine what would have caused this in the first place. Should I attempt to fix or part it out? I have had it running and it ran very smooth in spite of that damage. I also attached a picture taken off the computer of what the crank cover should look like (for comparison).

 

[bertsmobile1]

Ouch, that looks real bad.
I will double check the parts book.
It looks like there should be a thrust washer or similar on the end of that crank where it runs on the worn down shoulder.

 

[arch252]

I would have thought that as well but the parts manual only shows a snap ring. There is almost always a thrust washer there. How does this not happen with all of those models? Unlike the Kohler Courage I don't know of this being a common problem for this Kawasaki model.