[ucop27]

Here is the scoop, was riding yesterday, we rode 80 miles or so, then stopped for gas, left the station rode maybe 2 miles or so then jumped on snow covered ice, couple of inches of snow on it, we are cruising along between 70-80 and after about 5 miles or so the old ZR siezes up. Everyone says that it is running rich, so I am thinking maybe a coolant issue or maybe even an oil issue. I have had no problems when its held open for short periods, but longer pulls and she siezes up. Its the PTO side piston.

 

[ucop27]

IMO opinion it looks lean according to the plugs, but others have said that looking at the top of the piston it looks like its running rich.

 

[900geek]

by looking at that piston you are pretty much washed clean,lots of fuel,but those plugs tell a different story,you could be too lean on the needle and when coming off the mains into the needle you locked up,if you over heated it should have puked out the overflow and you would see,smell it,

 

[94ZR580]

It would be nice ot see more of the pistons and cylinders. You could have very easily pick up some water at your fuel stop. Both the plugs look ghostly, but did only one side seize and lose compression? If the carbs are still at outside temps, frozen, take a look at the fuel in the float bowl. I melted a piston after picking up some watery fuel and found ice pellets. little B-B's of ice in the float bowl. Because both plugs are showing lean I'd look to water in the fuel system.

 

[ucop27]

I am going to go out now and pull the cylinder and piston, only one side went down, from looking into the y pipe it looks like it was a 4 corner siezure. Not sure why the plugs look lean but the piston top doesn't.

 

[ucop27]

Here is the piston and cylinder, the cylinder seemd very dry to me when I yanked it apart, makes me think maybe its an oiling issue.