Seized 1982 CR 80

Dylan19302

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Jun 27, 2008
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Ok i was riding my CR 80 around my feild in the mud. After i thought I should wip down the road and clean all the mud off of the tires and anything i could. on the way back it started to die so i clicked it into a lower gear and it started to slow down more and it died. :ohmy: i went to kick it over and the kicker wouldnt move :yikes:. I started pushing it back and i told my dad. He said its seized. Then he said i needed to boar the engine out, new piston and pins. Is this true any other thoughts about this. is there any way i can free it up. (and yes ive tried kicking it hard.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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Merrillville,Indiana

Dylan19302

Member
Jun 27, 2008
111
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Well i do a routine maintenance almost all of the time. My dad says that a 2 stroke shouldnt be going as fast as it can down the road. is this true?
 

whenfoxforks-ruled

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Oct 19, 2006
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Merrillville,Indiana
Not if it is worn out. A brand new engine wears, the more it runs on top, the faster it will wear. Inside the owners manual is an expected time that certain parts last. Certainly you would not wear parts at the rate they recommend, but it would be good insurance against catastrophic damage. Depending on how you ride and maintain it you can stretch and make your own schedule. Just do not let parts run when they are close to being out of spec. You take it apart and check it, you will know.
 

Dylan19302

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Jun 27, 2008
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I just did a rebuild about 3 weeks ago. Ive only rode it with this piston 15 times. Is that all this will last.
 

_JOE_

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May 10, 2007
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Your dad sounds like he knows what he's talking about, maybe you should just listen to him? Most of the time when people run down the road they are on and off the gas. This heats up the engine then cuts off the lube. Keep doing it and presto! Siezed engine.
 

Dylan19302

Member
Jun 27, 2008
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0
Im just about to take the engine out of the bike again. I dont mind working on the bike. I actually like working on the bike its just im worried i need everything new.
 

Dylan19302

Member
Jun 27, 2008
111
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i know you need the engine out but what parts am i probally going to need to buy. I can get some used parts from a local cycle salvage.
 

whenfoxforks-ruled

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the usual, most damage is the cylinder and head. Chances are you need your cylinder cleaned and inspected. The bottom end needs the same loving touch. Slapping a piston and ring in basically, new.
 

Dylan19302

Member
Jun 27, 2008
111
0
Ok I got my engine apart and the cylinder was seized. I need a new piston, rings and bore out the cylinder. I just want to know why it seized. The piston has gashes up the one side. This is the same with one side of the cylinder. It looks like the piston scraped up the one side of the cylinder. The rings are like melted to the piston. Could it be the oil I was using or the oil mixture wasnt lean or rich enough. Also my dad found a website that said I was running too lean. I dont really know the difference between lean or rich could anyone tell me.
Thanks for all the help.
 

brax

Member
Dec 2, 2005
17
0
either your not mix'n your gas/oil right or the crank seals are leaking and cause'n it to run lean,
 

Dylan19302

Member
Jun 27, 2008
111
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im mixing my gas/oil to 32/1 which is what your supposed to mix them and the seals are brand knew when i last rebuilt it a month ago.
 

brax

Member
Dec 2, 2005
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0
yeah 32:1 shoulda been fine , check your carb main jets and for case leaks, something made it run lean unless you were bouncing it off the rev limiter for 20 mins straight
 

Dylan19302

Member
Jun 27, 2008
111
0
my engine wasnt leaking any oil and any seals were brand new when i rebuilt about a month ago. i just cleaned the carb perfect. I was riding it for about 15 min around a little track i made. then i went down the road to try and clean off any mud.
Also my dad talked to a few people and they said that i didnt work it in properly. does any one have any tutorials that you could give to work it in properly.
 

btm1948

Member
Jun 4, 2008
97
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just be realy easy on the bike when your breaking it in dont go balls out after just rebuilding the engine. do a search on breaking in your engine or if you have a shop manual for it then it will probably tell you what to do.
 

whenfoxforks-ruled

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Oct 19, 2006
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Merrillville,Indiana
On an overhaul. Start it and let it idle till the radiators start to warm. Shut it off and let it cool. Do it again. Listen to the motor, smell it, and feel it. Any doubt, turn it off. Take it for a leisure ride after the last cooling, 5-10 minutes, let it cool. Then go for 15-20 minutes, let it cool. Then it should be good to open it up. It may sputter on top the first time you clear it out good. If it still breaks up on top, its still tight, or you have jetting issues. If the piston has a single line scored down the exhaust side, the bridge was too tight. If the ring/top of piston seized, you may have did it?
 

brax

Member
Dec 2, 2005
17
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if its water cooled you could of had cooling issues, yes your suppose to let them break in right and seat the rings and all, but it shouldn't make your motor seize
 

Dylan19302

Member
Jun 27, 2008
111
0
Ok the guy that honed out my engine sayed it was because the engine was running 2 lean. My dad checked the jets and there all the way there supposed to be. what could be making it 2 lean?
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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Merrillville,Indiana
NOT RELATED TO THE OIL RATIO! Give that a break. Its the air fuel ratio is lean. An air leak somewhere. Rubber boot on the intake, reed manifold, head gasket(cr's are great for that one) left crank seal, or maybe the timing is advanced.
 
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