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1990 CR80 issues

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Hi, i purchased a 1990 cr 80 a couple weeks ago. It wasn't running well and burning tranny oil. So i checked the right crank oil seal and it was off so i installed a new one re assembled everything and the bike started no problem. the issue comes with the compression seems low and its very easy to kick over(never had an 80 only my 2002 yz 250) but it starts first kick np. the top end is new i checked everything an its in spec. Bore, piston end ring gap everything checks in. bike runs but when put in gear and you get it going it has not power and cuts out. Also the piston when at TDP isn't flush with the top of the cylinder like my yz 250 not sure if that's normal. the carb is clean and jets are stock. here are some pics of what im takin about. i ordered a flex hone for nikasiled cylinders to clean the cylinder a bit also.

http://imgur.com/a/eXcGc

any help would be greatly appreciated

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Hi, i purchased a 1990 cr 80 a couple weeks ago. It wasn't running well and burning tranny oil. So i checked the right crank oil seal and it was off so i installed a new one re assembled everything and the bike started no problem. the issue comes with the compression seems low and its very easy to kick over(never had an 80 only my 2002 yz 250) but it starts first kick np. the top end is new i checked everything an its in spec. Bore, piston end ring gap everything checks in. bike runs but when put in gear and you get it going it has not power and cuts out. Also the piston when at TDP isn't flush with the top of the cylinder like my yz 250 not sure if that's normal. the carb is clean and jets are stock. here are some pics of what im takin about. i ordered a flex hone for nikasiled cylinders to clean the cylinder a bit also.

http://imgur.com/a/eXcGc

any help would be greatly appreciated

Check the other crank seal as well. If that one is bad, it can make it feel low on compression and run badly.

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Check the other crank seal as well. If that one is bad, it can make it feel low on compression and run badly.

k i checked the other crank seal and saw a little bit of oil leakage. got my seal kit today and will be replacing all of them and well see if that helps

Edited by Pona64

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