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Toasted my engine?

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I was replacing the piston in my DR and the pin took some force to push into the piston. I slipped and the rod 'shifted' to the left, and afterward there was a pronounced side-to-side freedom of movement, at least 1/2". There was nothing to do at the point but finish the build so I did, and when I finally got it started, lo and behold, a loud >CLACKCLACKCLACKCLACKCLACK<. I removed the head again to check if there was piston to valve contact or any other obvious noise-inducing damage, but nope - the piston is fine, the valves are fine, the cylinder wall is fine, nothing apparent causing the noise. Did I toast my rod bearing when it shifted/slipped?

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If your valves were adjusted with too much clearance they'll make a racket. Hopefully it's that and not your bottom end getting ready to grenade.

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What was your reason for replacing the piston? These dr motor dont wear out unless miss used.

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forged hi comp piston? as Brian says they are noisy especially when cold. mine inside my shop sounds really loud, outside not bad, and when hot sounds ok.

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I'll recheck the valves again just in case, thanks. Had to adjust them quite a LOT for the new lumpier cam, so maybe they need another look.

This is loud like LOUD, like when it was running it so loud it was drowning out the noise from the exhaust - all i could hear was the CLACKCLACKCLACK from the motor, overpowering the CHUFFCHUFFCHUFF from the GSXR can.

Is that how loud the JE HC piston is when cold? This seems excessive to me...Also, any thoughts on the rod movement?

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I've heard that noise before........In my case, it was the wristpin.....

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I've heard that noise before........In my case, it was the wristpin.....
Any details? This is all brand new stuff, pin, piston, cliips...put moly paste on the pin for installation so I can't see where the pin would be bad...?

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I'll recheck the valves again just in case, thanks. Had to adjust them quite a LOT for the new lumpier cam, so maybe they need another look.

This is loud like LOUD, like when it was running it so loud it was drowning out the noise from the exhaust - all i could hear was the CLACKCLACKCLACK from the motor, overpowering the CHUFFCHUFFCHUFF from the GSXR can.

Is that how loud the JE HC piston is when cold? This seems excessive to me...Also, any thoughts on the rod movement?

The J&E piston is not that loud when cold. Certainly no "CLACKING" should be going on....:banana:

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I was replacing the piston in my DR and the pin took some force to push into the piston. I slipped and the rod 'shifted' to the left, and afterward there was a pronounced side-to-side freedom of movement, at least 1/2". There was nothing to do at the point but finish the build so I did, and when I finally got it started, lo and behold, a loud >CLACKCLACKCLACKCLACKCLACK<. I removed the head again to check if there was piston to valve contact or any other obvious noise-inducing damage, but nope - the piston is fine, the valves are fine, the cylinder wall is fine, nothing apparent causing the noise. Did I toast my rod bearing when it shifted/slipped?

The con rod side clearance limit is 1mm (.039") measured at the crank pin. This would equate to quite a bit more than that at the small bearing end..... but not 1/2" :banana: So how much force are we talking when you slipped and the rod shifted? You didn't "slip" with a BFH did you? :lol:

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The con rod side clearance limit is 1mm (.039") measured at the crank pin. This would equate to quite a bit more than that at the small bearing end..... but not 1/2" :banana: So how much force are we talking when you slipped and the rod shifted? You didn't "slip" with a BFH did you? :banana:

BFH in this case would be "Big Effing Hamfist" - definitely applied a fair amount of force to the one side when my 'balance" hand slipped off the opposite side of the piston, but I couldn't imagine it would be enough to ruin the rod bearing at that moment. Of course, after that moment is a different story...

Looks like I'm gonna tear it down again and see what I can see before I split the cases, or if I split them... :lol:

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Quote:

Originally Posted by jkm712

I've heard that noise before........In my case, it was the wristpin.....

Any details? This is all brand new stuff, pin, piston, cliips...put moly paste on the pin for installation so I can't see where the pin would be bad...?

1st - was a used Honda XR250. The engine had a very pronounced 'Clacking' sound. 'Clack' was the exact word I used to describe it. I bought the bike from a dealer who told me that it was most likely just an exhaust valve out of adjustment. It wasn't. The end of the rod had worn 'egg-shaped' and was permitting the wrist-pin to move up and down within the rod end. It was loud.

2nd - was a used DR650. I brought the bike home and changed the oil. On start up, I heard alot of excessive noise. It wasn't exactly the 'clack' I'd heard in the Honda, but was metal to metal. Before any repairs were made, I took the bike to 3 different dealerships/mechanics to see what they thought the noise was. All thought it was a valve, but I'd already had them adjusted. After hearing that, one immediately said it was a wrist-pin. Turned out there was alot of issues inside the top of the bike, but a worn wrist-pin was one of the issues.

Since everything you put in was new, you'd have probably felt any sloppy fitting parts.

Just as something to check before you go to the bother of tearing things back apart, are you sure that the cam chain tensioner was properly re-installed?

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Quote:

Originally Posted by jkm712

I've heard that noise before........In my case, it was the wristpin.....

Any details? This is all brand new stuff, pin, piston, cliips...put moly paste on the pin for installation so I can't see where the pin would be bad...?

...Just as something to check before you go to the bother of tearing things back apart, are you sure that the cam chain tensioner was properly re-installed?

Thanks for the details - I don't think think these issues would apply in this case.

Checked the cam chain tensioner 2x for correct installation, and 3x the timing. I think I'm pretty much convinced it's the rod/pin/bearing/crank at this point. :lol::banana::banana:

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You're welcome. The cam chain tensioner was a long shot, but thought I'd mention it.

You describing that 'Clack' sound brought back bad memories. Although, to that little Honda's credit, it 'clacked' all summer long before it got so loud I had to do something about it. Before that, I had never heard of a rod end wearing egg-shaped.

Good luck. I hope you'll let us know exactly what it was once you find it......jkm

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BFH in this case would be "Big Effing Hamfist" - definitely applied a fair amount of force to the one side when my 'balance" hand slipped off the opposite side of the piston, but I couldn't imagine it would be enough to ruin the rod bearing at that moment. Of course, after that moment is a different story...

I can't believe you could damage the rod in any way with just your bare hands.

I'm not real clear about where you were seeing 1/2" of play.

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I can't believe you could damage the rod in any way with just your bare hands.

I'm not real clear about where you were seeing 1/2" of play.

I have a talent for being able to break anything just by thinking about it. :banana:

Seriously, I couldn't imagine I could damage the rod or bearing either. The play was lateral movement at the top/small end of the con rod. I just took a short video of the noise and I swear while listening it sounds more like cam/valve/rocker/follower noise. I'm trying to edit it down to an uploadable size now...

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Of course the sound in the vid file changed considerably due to the compression the hosting site uses, but I think you can still hear the clacking pretty clearly and if you listen closely when the cam is at the top end you hear a faint metallic ringing as well. This just doesn't sound like a rod bearing to me...

And found another YT vid with a DR making the same noise mine is now making

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BFH in this case would be "Big Effing Hamfist" - definitely applied a fair amount of force to the one side when my 'balance" hand slipped off the opposite side of the piston, but I couldn't imagine it would be enough to ruin the rod bearing at that moment. Of course, after that moment is a different story...

Looks like I'm gonna tear it down again and see what I can see before I split the cases, or if I split them... :lol:

Like Procycle said.. I can't imagine rod bearing damage from your hand even if you are a NBA candidate.... and unless you are bionic I doubt you put a bend in your rod. Deck height? Mine actually required some material removal from the cylinder to get the squish band correct so I doubt your piston is smacking the head...... :banana:

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I've heard loose spark plugs that made loud clacking noises. Just something to check.

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