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2 Stroke Dirtbike Maitenance

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Hi everyone! I have been looking at a 1986 CR80. They priced it at $350 and they said it needs new rings. I am not to familiar with 2 stroke maintenance and was wondering how and what other type of things you would need to do regularly. The only thing I know is a top end rebuild every 100 hours or so on the engine. Correct me if I am wrong. If you can please tell me how often you would need to do it! Thanks I appreciate it!

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Id say a top end when you start losing compression. Youll get a million answers for this. Put in a fresh one (and prob a cylinder plating or honing on something that old) and measure compression. If you arent racing or competitive, top ends arent as critical as say, oil changes and filter cleaning. Otherwise its more like 40 hours for a too end, again assuming you arent pinning it everywhere. With an 80cc tho itd be tough not to.

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And get a manual for whatever bike you buy. Itll pay for itself and answer all the basics for you

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I dont think I would try to get 100hrs from an 80 top end. Usually the smaller the bore the more it needs top ends. Luckily they are cheaper too.

Other than that,change tranny oil every 10 hrs or so...clean the air filter when its dirty. Thats about it.

Edited by nofb

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Keep that air filter clean! Change tranny oil often. I change mine every 4-5 hours of ride time. I agree with freshening up the top end when you start to lose compression.

Othrr than that, just your regular greasing, cleaning, etc.

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Thank you everyone! I appreciate it. I have another question. How should I be riding a 2 stroke? Hard or easy? And how long does it take to replace rings on a piston?

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On a CR80 your probably going to have to keep it strung out to get anything out of it.. Replacing rings time will vary with experience doing such. First time you do it will probably take a while, but the next will go a lot quicker as you know how it goes.

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I'd by the Clymers manual for what ever bike you get. Shows the maintenance schedual for the bike. Apart from replacing rings and top ends, it's not much. I only trail ride on my 2 banger, change the gear oil every 10 hours, clean the filter every ride, check and grease bearings every so often, that sort of stuff...

Thank you everyone! I appreciate it. I have another question. How should I be riding a 2 stroke? Hard or easy? And how long does it take to replace rings on a piston?

You will be in the high rpm most of the time, that's where all the power is at.

Edited by Dunno207

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Ok guys I really appreciate. Now that I am thinking about it I don't have a huge area to ride so I am wondering if I should get another bike. I am 5 foot 2 inches and around 100 pounds hahaha sorry!

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Ok guys I really appreciate. Now that I am thinking about it I don't have a huge area to ride so I am wondering if I should get another bike. I am 5 foot 2 inches and around 100 pounds hahaha sorry!

I would advise trying to find something a bit newer at least. '86 is getting back there to the point of going to be hard to find some parts for it. You'd be much better off working with something inside the last 10 years.

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A honda cr85 should fit you pretty well, rides higher then an 80. I believe they have longer suspension travel. not a 100%. only ever rode one, but it was FAST!!!!. had to lean over the bars to keep the front tire down. I believe it was around a 1995 and he paid 500-600 bucks which was pretty cheap. the bike was in great shape. But you can find those deals out there. good luck!

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It should only have one ring. that's one reason you have to replace them more often

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There is ABSOLUTELY no way it needs "just a ring". It will have a LOT wrong with it, and some of that you won't even know about. That is why it is only $300.

Find something newer, young mechanic.

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Anything before 93-95 will be hard to find parts. For something not even twice the price ill bet you can find a lot newer, 98-99 even. Be careful with someone telling you it 'just needs' something. If it 'just needed' a $15 part and 45 mins of time hed have done it and sold it for more, imo.

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2 stroke maintenance is easy!! if your a good 4 stroke mechanic this should easy for you! the bike is most likely lossing compression and you may need more than rings done. there can be a chance that the piston may be scored or even the cylinder can be also. so if you can take the pipe off and look inside you may see the piston and cylinder and judge it yourself. if your cylinder is still good id order a topend kit for around $130 bucks which includes the piston,rings, bearing, wrist pin, gasket kit. if you want to put in more money and do it right get the cylinder honed or get it replated. disassembling it is simple. all you need to do is first drain out the coolant (if water cooled) remove the head then pop off the power valve cover and remove your power valve linkage the you can unbolt the cylinder. its that simple since theres no timing or valves you need to mess around with. make sure you pay attention because one of those postion dowels can fall off and you be screwed if you put it back on without that on(doing a top end rebuild on my cr125 right now and lost the darn pin and now waiting for it to be shipped. you can see the smallest thing will hold you back). so while thats all off check your crank shaft for play and your main bearings for noise. i recommend you get a manual, its all there and tells you every thing and most important part is getting the bolt torque right! well i hope this answered your question and good luck!

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Anything before 93-95 will be hard to find parts. For something not even twice the price ill bet you can find a lot newer, 98-99 even. Be careful with someone telling you it 'just needs' something. If it 'just needed' a $15 part and 45 mins of time hed have done it and sold it for more, imo.

Not true. I can find anything I need for my 88 rm80. And I can also find any part I need for my 78 yz80

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