06 RM 250 Piston ring end gap

[XXX Adrenaline Spo]

A friend of mine has a 2006 RM250 two stroke with a standard bore (I Think). He brought me the cylinder to look at and try to determine the cause of a seemingly excessive piston ring end gap. He meausred nearly .025" of piston ring end gap with the old rings. My question is, Is .025" too much? I told him the cylinder cant be too worn because the plating is all still in place on the cylinder. Am I right about this? and is .025" OK?? Im just trying to help out a friend so any help will be greatly appreciated.

Thanks, Stuart

 

[hot125mod]

measure the bore with an inside mic, i hope there is plating on it off the top of my head i cant remember what a 250 end gap is supposed to be. sorry

 

[hot125mod]

get a manual

 

[hot125mod]

it will tell you everything you need to know there about $20 from clymer

 

[XXX Adrenaline Spo]

sometimes manuals are not all that great in real world scenarios such as this one.

 

[XXX Adrenaline Spo]

especially not clymer

 

[jaguar]

Multiply bore in inches by .004" for the top ring and .005"for the bottom ring according to Wiseco. http://wiseco.com/PDFs/Manuals/RingEndGap.pdf
A 66mm bore is equal to 2.6"
2.6times .004 is .0104"