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Discussion Starter · #1 ·
Just bought it and found out now it needs a rebuild. Oil is blowing by the crank case I guess so it needs new piston rings. Anyone know how much this would cost and if its ok to drive the rest of the season?

Also you think its worth doing it?
It has 42000 K on it.

Much appreciated.
 

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How much oil does it use? Some blowby is to be expected with older engines. Does it fog the neighbourhood every time you ride it? Does it put the entire contents of the crankcase into the airbox every 328 miles? What?

You're the only person who can answer the "is it worth it" question. Is it worth it to YOU?
 

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The Toad
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Is it smoking blue smoke? When you let off the throttle, decelerate and roll the throttle back on worn rings will give you a puff of blue smoke. Worn valve guides will give you a more constant stream of smoke.

If you need a rebuild just the pistons and rings will cost you $300. 16 valves at $20-25 each, guides $16. Gaskets and you're at $1000 just for parts. Then you've gotta bore the cylinders. Who knows what else is worn out inside. So you gotta get a manual and mike out all the clearances. A rebuild might cost you $2K in parts by the time you are done. If you have a shop do it that's another $2K for labor. Easily more than the bike is worth.

How's the tranny? Better check it too. Trannies have been getting weaker in the quest to keep weight down.

Myself, I've given up on trying to resurrect late model Japanese bikes. Parts prices are insane. Sportbikes are simply throwaway items these days.

Since you already bought it it might be worth it to tear the top end down and check all the clearances. It the cams and valves are still okay and the rod play is still good then it might be worth it to do a bore job, new pistons/rings and just run it 'til it blows up. Then throw it away. Depends on how much you paid for it. Hope it wasn't much.
 

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Discussion Starter · #4 ·
Thanks for the replys. No smoke whatsoever that i have noticed at all. They only noticed because they went to clean the carbs and found some oil in there. I have not even noticed it burning oil. I will have to check. I will have to ask how much oil they found. Tranny is fine as well as far as i know. I am not a mechanic by any means though.

I paid 4200 which ois prob to much. I assume driving it as is wont hurt it any more?
 

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Ah, I see. With the info you've provided, I'd say if it's not using a measureable amount of oil, it's nothing to worry about - some oil is going to naturally migrate into the carb/airbox area - that's where the crankcase is vented.

Get Religion on checking that oil level. If it's less than a quart every 2000-3000 miles, just learn when to add some. Carry a spare quart on long trips (if you're into that long-distance thing) and Ride the Damn thing. :cool:
 

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The Toad
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Yeah...

Ah, I see. With the info you've provided, I'd say if it's not using a measureable amount of oil, it's nothing to worry about - some oil is going to naturally migrate into the carb/airbox area - that's where the crankcase is vented.

Get Religion on checking that oil level. If it's less than a quart every 2000-3000 miles, just learn when to add some. Carry a spare quart on long trips (if you're into that long-distance thing) and Ride the Damn thing. :cool:
... for example my old 81 CB900 used a quart of oil about every 2000 miles, even when new. That consumption never changed in 25K miles. I think it was just the breather sucking it into the intake. My KZ750 also used oil and when I tore it down at 55K miles the combustion chambers were virtually clean. Some bikes just use oil.
 

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Discussion Starter · #11 ·
There's another thread under maintenance called: "My Friend Earl" you might want to read. Lots of info in there on oil choices.

Also, I was suprised no one suggested a simple compression test on the cylinders. It will tell you if there are issues with rings, valves, etc.
Yes actually my bud is bringing home his kit from work to do that up this weekend. Hope all goes well with it.

Thanks all
 
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