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1991 CR250 New Top End -- Wiseco or OEM?

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My '91 CR250's top end took a dump on me and needs a rebuild. I've never had to rebuild a top end before and I was curious if Wiseco pistons are worth the lesser price than OEM? I know "you get what you pay for", but I don't race this bike and don't plan to, I just use it for dirt back roads and trails. Anyone have any experience with Wiseco top end rebuild kits? Thanks!

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Since you don't race, an OEM cast piston will allow a tighter fit when cold (less piston slap / rocking in the bore).

Inspect your cylinder for damage to the plating and have it measured for wear / taper / out of round before simply slapping a new piston in there.

(you have to measure it anyway to know what replacement piston size to order)

 

OEM / cast piston are of high quality, durability or strengh issues of cast pistons are from stretching maintenance intervals too long.

 

Also determine WHY your engine 'took a dump',  an air leak / running lean, torn air boot etc.  will quickly ruin you newly rebuild top end as well.

Edited by mlatour

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Since you don't race, an OEM cast piston will allow a tighter fit when cold (less piston slap / rocking in the bore).

Inspect you cylinder for damage to the plating and have it measured for wear / taper / out of round before simply slapping a new piston in there.

(you have to measure it anyway to know what replacement piston size to order)

 

OEM / cast piston are of high quality, durability or strengh issue of cast pistons are from stretching maintenance intervals too long.

 

Also determine WHY your engine 'took a dump',  an air leak / running lean, torn air boot etc.  will quickly ruin you newly rebuild top end as well.

this is great advice, even if it turns out to be just a matter of hours on the old piston you really need to make sure, if not that new piston will be toast long before it should be.

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Since you don't race, an OEM cast piston will allow a tighter fit when cold (less piston slap / rocking in the bore).

Inspect you cylinder for damage to the plating and have it measured for wear / taper / out of round before simply slapping a new piston in there.

(you have to measure it anyway to know what replacement piston size to order)

 

OEM / cast piston are of high quality, durability or strengh issue of cast pistons are from stretching maintenance intervals too long.

 

Also determine WHY your engine 'took a dump',  an air leak / running lean, torn air boot etc.  will quickly ruin you newly rebuild top end as well.

 

I ran it without coolant...  :banghead:  Yes, I deserve all the shame in the world for my stupidity. I bought it as a learning tool to learn how bikes work and how to fix them, so I guess this is another learning opportunity; an expensive one at that. Otherwise, it doesn't leak or run lean (I've checked it all and have adjusted it properly).

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