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How do I fix this top end!?

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ImageUploadedByThumper Talk1448238978.162085.jpgImageUploadedByThumper Talk1448239080.546417.jpgImageUploadedByThumper Talk1448239121.480542.jpgImageUploadedByThumper Talk1448239170.484224.jpgImageUploadedByThumper Talk1448239261.622616.jpg

Okay after looking at all those pictures, I need you guy's help. It's obvious that I need a new piston and rings. The cylinder will need to be plated or bored. Currently this is off of an 08 rm85. I was thinking I could bore it out to a 105 and get a new piston and rings to match. Do you guys think that would be the right move or not?

Also it's clear to me after reading other forms, that I have "detonation" issues. How might I go about fixing this?

Last thing is on a 105 bore what all needs to be done? Obviously boring out the cylinder and new rings and piston but is there more to it than just that?

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I personally would send the cylinder to Millennium and have it bored to a 105 and then have them re-plate it and match the bore up to a Wiseco piston kit that I bought from them.  They may be able to fix the head too so ask whom ever you choose to fix the cylinder about the head as well.  As for possible detonation issues, I'm not seeing that ~ it just looks like that piston got loose from being used too long and then crashed into the exhaust port.  You could consider picking up a JD Jet kit, but in all honesty it doesn't look that bad.

 

What were you doing when it broke? and do you have any idea of how old the piston is?

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I personally would send the cylinder to Millennium and have it bored to a 105 and then have them re-plate it and match the bore up to a Wiseco piston kit that I bought from them. They may be able to fix the head too so ask whom ever you choose to fix the cylinder about the head as well. As for possible detonation issues, I'm not seeing that ~ it just looks like that piston got loose from being used too long and then crashed into the exhaust port. You could consider picking up a JD Jet kit, but in all honesty it doesn't look that bad.

What were you doing when it broke? and do you have any idea of how old the piston is?

I was in about 4th gear throttle pinned and it just sputtered out. Got the bike back home and took out the spark plug first things first. Realized that the bottom of the spark plug was broken off! I figure that is why everything is so scared up on the head and piston from that piece of loose metal banging into each of the two. And from what I see it's the original piston from Suzuki. I bought the bike about 6 months ago and it had always ran fine So I never even bothered to tear it down. I guess I trust people a little to much and figure they know to rebuild a 7 year old bike atleast once. So since they didn't I want to do it right know.

And on the spark plug I'll include a pic of what broke off.ImageUploadedByThumper Talk1448241507.178372.jpg

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Your not the only one.  I bought a '02 RM250 in '04 and was told that it had been rebuilt.  I knew I should have asked for proof but I "kind of" knew the guy so I rusted him, on the 3rd ride the stock piston blew apart and took the cylinder and head out with it (Millennium fix it).

 

In your case Suzuki has been known to spec out some high dollar spark plugs (especially in the RM125) just because of a harmonic problem in some model years (the plug ground will vibrate off in some cases).  Not sure if your 85 is the same way but I would check into it just to be sure when your putting it back together.

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Your not the only one. I bought a '02 RM250 in '04 and was told that it had been rebuilt. I knew I should have asked for proof but I "kind of" knew the guy so I rusted him, on the 3rd ride the stock piston blew apart and took the cylinder and head out with it (Millennium fix it).

In your case Suzuki has been known to spec out some high dollar spark plugs (especially in the RM125) just because of a harmonic problem in some model years (the plug ground will vibrate off in some cases). Not sure if your 85 is the same way but I would check into it just to be sure when your putting it back together.

You think I need to split the cases on it or will it be okay. And did you think millennium was reasonable on their price?

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With the stress of a larger piston it wouldn't be a bad idea to freshen up the bottom end. Is there any up and down play on your connecting rod? Even if its the slightest amount it needs to be replaced

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You think I need to split the cases on it or will it be okay. And did you think millennium was reasonable on their price?

 

To ensure that there's nothing stuck (or hiding) in the bottom end, when ever a 2t blows a piston you should pull the motor and inspect / clean out the bottom end.  And as DylDog stated, then you could also inspect the crank & rod bearings for wear.  As for Millennium's prices, I found them to be a good combination of price verses quality.  Which means that their not the cheapest but when their done you will have a cylinder that's actually better than new (plating wise) and it'll be machined to fit the piston that you buy from them.

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Well I already have more in this bike than it's worth. ($1300)I've had to totally rebuild the transmission because it once again the person who had it before me didn't have a clue as to how to care for a bike. So replacing the bottom end isn't even something I would consider. I really don't even want to split the cases. I'd like to just get it replated slap a new piston and rings in it and sell it.

Overall it's not a bad looking bike so I shouldn't have a problem selling it.

Edited by Ian8or

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You could do that. There's a chance you'd crunch a bearings quickly if there was any shrapnel in the crank. Personally I would feel bad selling a grenade to an unsuspecting buyer. Did you check for play on your connecting rod?

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Haven't had time yet got home from school and had to leave immediately will check it tonight and get back to you guys. And there is not that much shrapnel in it to he honest. Around the jug it was super clean.

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Well I already have more in this bike than it's worth. ($1300)I've had to totally rebuild the transmission because it once again the person who had it before me didn't have a clue as to how to care for a bike. So replacing the bottom end isn't even something I would consider. I really don't even want to split the cases. I'd like to just get it replated slap a new piston and rings in it and sell it. 📎ImageUploadedByThumper Talk1448313796.144116.jpg

Overall it's not a bad looking bike so I shouldn't have a problem selling it.

that's the name of this sport, I have more into my 97 cr250 than I could ever recoup, we buy and ride these because we love them, not to save money.

 

you need to decide if its worth fixing.

 

don't just half arse the fix and sell it...you are going to pass a potential problem to someone else.

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