piston size

[woodsracer144]

hey i have a lrd cyl with a piston with a 69.00 mm piston... the number is like this
3622I

203M06900
then a down arrow

I was going to put this on a ATC bottom end i have with the hot rods crack i had in my trx one but i found a crack in the piston and i would like to replace it if i could... or find a stock bore 86

[Langbolt]

It's a WISECO piston......but NOT for a 250R.

They start with 526 or 562 ('86 style or '87-89 style)

I checked to see if it was a Yamaha YZ250 piston but that part number is 234 or 542

???????

Geez! A search option on:

http://www.pistons-online.com/motorc...a&st=39&end=46

would sure help!

[woodsracer144]

well dang this is weird... im gonna have to check the number again... im positive thats the one though..

[86 Quad R]

if/when you do varify the number call the link posted or call wiseco direct. either should be able to tell you exactly what piston you have/need.

[woodsracer144]

man im on crack! its 526M09600 niy o found a crack on my cylinder skkirt as well and its pissin me off so now i have to resleeve it! damb it anyway!

any body have a good sleeve kit to use?

[86 Quad R]

does the cylinder have a good aftermarket porting? if so, your best bet is to get a replacement sleeve from la sleeve and have a reputable builder install it. this will put you back at oem bore tho. but if the cylinder is strong in power you'll be fine.

[woodsracer144]

yes, it is ported by LRD and has a O-ring head gasket in it as well. im getting it resleeve but dont know if i sould go with a 310 or what...

[86 Quad R]

personally i'd go back to oem bore. there is a "thick" oem bore sleeve that be installed that will allow you to bore as many as 22-24 overbores.

[woodsracer144]

could you post a link to the "thick" one... i want to get as cheap of one as i can with a piston... if they come with it...

[86 Quad R]

you'll either have to contact la sleeve or an engine builder for the sleeve and i do not think the piston will be coming with it. more than likely it'll need to be purchased seperately.