What causes piston to run lean???

[zubie96xp]

I have a 96 XP recently cleaned out the carbs (1fastki.com good **** recommended) but one of my cylinder heads was mangled and the other who knows basically i have take apart the entire engine, although i have not took a closer look at the crank shaft just removed the cylinder head......My question is the right piston and ring coming from the drive shaft seems to have good lubrication and ther is a small deposit of oil i can see through the crank shaft but the left has no oil and is extremely dry which to my belief cause the piston to go but WHAT IS CAUSE OF OIL NOT GETTIN TO THAT LEFT CYLINDER, right oil (you can see the golden brown but left dry dull gray??? below is a link wit some pixs....
http://userweb.suscom.net/~hockey27/xpp.html

[Bill O'Neal2]

Re: What causes piston to run lean???

You should closely look over the oil injection system. You will be looking for a cracked oil line going to that clyinder, or a stuck check valve in the RV cover that is not allowing oil into that side of the motor. It is possible you need an oil pump or oil block off and go to premix.

But, do not assume that oil is your problem. Even though it looks dry in the clyinder, that could be from extreme heat if that clyinder was sucking air from a bad crankcase seal or that carbureator was not delivering fuel to that clyinder.

The crankshaft looks light grey too, so I think you will need to replace it, as the bearings on that rod look as though they either did not get lubricated or were overheated or both.