[johnnington]

During a 30 mile ride recently, my AT developed a tapping coming from the rear cylinder. Following a tear down, I found the front cylinder oil jet had come loose and had found its way to the bottom of the crank case which caused some metal to be shot into the rear cylinder and knackered the small end.

Anyone ever seen this before? These jets should be held down with the cylinder skirt so should never come loose!

 

[steinberg]

Never heard of that before, but a potential concern I suppose. Is the jet cast as part of the motor or is it a separate part that's fitted/screwed to the motor?

 

[johnnington]

Never heard of that before, but a potential concern I suppose. Is the jet cast as part of the motor or is it a separate part that's fitted/screwed to the motor?

It's a separate part that presses into the case. The o-ring takes up the clearance between the two and then the cylinder skirt should lock it in place. Very strange...