Need help!

michdude

New Member
Apr 26, 2012
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0
0
Newbee here,

I have a problem I hope those here can help. I recently purchased a blaster with a non running yz 490 in it. I find out that not only did the rings siezed up but the piston skirt is gone on one side as well as the bottom of one side of the cylinder sleeve is gone as well. The engine case number suggests its a 1986 motor. My question is, can I use the cylinder even though its missing part of the sleeve? Not sure if its needed for support or not? If not then I have an opportunity to purchase a used 1982 cylinder and head combo, but not sure it would fit my 86 case? Is there any way to cheaply solve this or any other yamaha engines that interchange with my 490? Or do I give up and look for a different engine? Very confused! Look forward to a reply. Thanks.:(
 
Post a pic of the cylinder missing a sliver would be ok but a chunk would probably cause the same issue you are dealing with now IMO!
 
You need a
New
Jug or the one you have resleeved. You will have to split the cases to clean out the broke piece of the piston and check for case damage.
 
Pics are a must!!!

Yes if theres a chunk missing you will need a resleeve.To be honest if it were me id send it to ken oconnor and have him resleeve it that way you get a new oem bore/sleeve fresh to start on and you know its done right.

when this thing is up and running correctly i bet it will be a BEAST!!!Definately worth a rebuild if the swap was done correctly.