Piston Hit Valve, spark plug melted

I bought a used 2003 fjr1300 with 26k miles. After I bought it I changed the spark plugs, oil, and air filter, checked valve clearance. Also I changed the timing chain and CCT tensioner (the bike made a rattling noise around 3k RPM (fixed)). After I put it all together, the bike had a ticking noise. It sounded like valve ticking. The rattling noise around 3k went away (changing the CCT fixed this). But I started to hear the ticking noise. Not sure if it was there before and I did not hear it, or if I messed up the timing. I triple checked the timing before I put it together (it was “close” When lining up the timing marks do they have to be 100% exact? Cause I think mine was SLIGHTLY off, but if I moved it 1 tooth the other way, it would make it SLIGHTLY off the other way…..).

Anyhow I drove the bike for about 170 miles.....
After stopping at a stop sign, I gave light throttle, the bike started moving, got up to about 20 mph and then I heard a quick rattle (cam chain skip a couple teeth on crank). I started to pull over to the right (engine was still running (rough)). By the time I stopped moving, the engine shut off on its own.

I towed it home, took it apart, tried to manually spin the crank shaft and it gets stuck at a certain point (I’m assuming piston hitting value). I took the valve cover off, and sure enough timing if off by 1-2 teeth.
Then I took the spark plugs out and found #1 exploded inside. It was really tough to unscrew it. See the attached picture of the plug.

I borrowed a borescope to look inside

first, the bore scope would not fit into any other cylinder, it fit snugly only into the bad one....not good

On the pictures attached you can see a piece of metal coming up into the spark plug thread. This piece of metal is infused into the piston, and at one point this piece of metal hits the thread and i cant turn the crank anymore.

Also after closely examining the monitor while spinning the crank i was able to spot a "hole" in the cylinder where i can almost see crank shaft movement deep down low. very small hole, but its there

My questions…
If the timing was off by one tooth, could this happen? after 170 miles of driving?
Should i rebuild the motor or buy a new used one on Ebay?
Any suggestions from the community would be appreciated. My wife is grilling me for buying a used bike instead of a new one.

Can't see your pictures, but I can still answer your questions.

No, having the timing off by one tooth will not cause engine failure. Many folks have run their bikes in that situation with no known failures. It just runs badly. Something else went wrong with the CCT and you skipped multiple teeth, and this is what caused the failure.

If I were in your situation I would try and find a replacement engine. The cost of repairing your top end will probably exceed the cost of a low mile engine.

Sorry to hear of your troubles. Good luck with the repairs.

You should kiss your wife's *** and tell her she was right. Then buy a 2013 FJR

If the cylinder wall is ok and you can find used parts cheap, the engine may be salvageable.

Fred is likely correct, a used engine will be cheaper and it is a much easier fix.

Without pics it's very hard to say, but it sounds like something fell into the cylinder, rather than a timing issue.

Several bikes have gotten the timing wrong, either improper assembly or carelessly allowing the crankshaft sprocket to slip a tooth while checking valve clearance, and one tooth will not destroy the engine but it runs awfully.

Early bikes had a ticking issue, but that was from a valve guide problem, not anything actually striking inside the engine.

Surely the spark plug wasn't too long????!?!?!?!?

You say hole in cylinder.... Is it cylinder, or piston?

As for posting pics, they must be hosted on a site such as Photobucket or Flickr, where you can get a URL that points a browser to the picture. Put that URL into the image tool in the post editor while you edit or create the post.

Wouldn't matter how far off the timing was-a piston should never contact a plug...If the plug was too long it could possibly fuse to the piston crown and cause what you describe..Can you reach down in there and break off the protruding piece of metal and see if this allows full crank rotation ? If there was interference it might cause valve timing to jump..If the piston isn't holed you might get away with removing the piece of metal-helicoil the plug hole and reset the valve timing.

wfooshee said:

Without pics it's very hard to say, but it sounds like something fell into the cylinder, rather than a timing issue.
Several bikes have gotten the timing wrong, either improper assembly or carelessly allowing the crankshaft sprocket to slip a tooth while checking valve clearance, and one tooth will not destroy the engine but it runs awfully.

Early bikes had a ticking issue, but that was from a valve guide problem, not anything actually striking inside the engine.

Surely the spark plug wasn't too long????!?!?!?!?

You say hole in cylinder.... Is it cylinder, or piston?

As for posting pics, they must be hosted on a site such as Photobucket or Flickr, where you can get a URL that points a browser to the picture. Put that URL into the image tool in the post editor while you edit or create the post.

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I was able to post the pictures on Flickr, here is the link https://www.flickr.com/photos/95353385@N04/8693613158/in/photostream/

Yes, hole in the piston, not cylinder.

Hard to believe that the plug was too long, bought all 4 plugs at the same time. I will double check.

Chuck35 said:

You should kiss your wife's *** and tell her she was right. Then buy a 2013 FJR

If the cylinder wall is ok and you can find used parts cheap, the engine may be salvageable.

Fred is likely correct, a used engine will be cheaper and it is a much easier fix.

Click to expand...

Yes, that is exactly what she wants me to do. I am trying to avoid that situation.

Fred W said:

Can't see your pictures, but I can still answer your questions.
No, having the timing off by one tooth will not cause engine failure. Many folks have run their bikes in that situation with no known failures. It just runs badly. Something else went wrong with the CCT and you skipped multiple teeth, and this is what caused the failure.

If I were in your situation I would try and find a replacement engine. The cost of repairing your top end will probably exceed the cost of a low mile engine.

Sorry to hear of your troubles. Good luck with the repairs.

Click to expand...

What could have gone wrong with the CCT?. This was a brand new one from YAMAHA (the newer model of it). is replacing an engine a complicated procedure?

vpantus said:

What could have gone wrong with the CCT?. This was a brand new one from YAMAHA (the newer model of it).

Click to expand...

Did ya remove the retaining clip in it when installed?

lnewlf said:

Wouldn't matter how far off the timing was-a piston should never contact a plug...If the plug was too long it could possibly fuse to the piston crown and cause what you describe..Can you reach down in there and break off the protruding piece of metal and see if this allows full crank rotation ? If there was interference it might cause valve timing to jump..If the piston isn't holed you might get away with removing the piece of metal-helicoil the plug hole and reset the valve timing.

Click to expand...

I would first have to reset the timing in order to complete a full rotation. But yes there is a hole in the piston crown. When i look at the piston through the borescope and turn the crank, i can see the crank shaft below turn. Small hole, but i can see it deep, deep down below.

I suppose plug being too long is a possibility. I would check , but as you can see in the picture, the plug is squashed so it would be hard to get an accurate length of it.

marcusorelius said:

vpantus said:

What could have gone wrong with the CCT?. This was a brand new one from YAMAHA (the newer model of it).

Click to expand...

Did ya remove the retaining clip in it when installed?

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The clip that held the CCT in the "retracted" position? the clip that was in the slot where the bolt gets screwed into? this clip correct? if so yes.

What model number spark plug was it that you put in there?

I have no idea what the heck happened here, but the end of that plug looks really bad and a hole is a hole.

An engine swap isn't a simple affair, but it's easier than rebuilding the entire engine. The trick is finding a known good engine.

Fred W said:

What model number spark plug was it that you put in there? I have no idea what the heck happened here, but the end of that plug looks really bad and a hole is a hole.

An engine swap isn't a simple affair, but it's easier than rebuilding the entire engine. The trick is finding a known good engine.

Click to expand...

I purchased the same as stock ngk cr8e. is it possible that one of the plugs was not in the correct box? sure it is. I will check tonight,.

Looks like a spark plug issue to me. I wonder if the plug itself failed such that the electrode came loose and slid down.

Is that the valve stem all smashed into the piston? I'm wondering if the valve broke below the keepers and dropped. Where is the rest of the valve?

Please correct me if I'm wrong but can't the head be removed while the engine is still in the frame?

I looked at the pictures and am pretty sure I see a valve sticking into the crown of the piston. looks like the valve broke, got imbedded into the piston, and beat the spark plug up pretty good.

I have no idea what broke the valve. Maybe contact after a chain slip. Maybe some other problem. Sucks, but it looks like used motor time. If you will not be doing this engine swap yourself then, while you may not want to hear it, I would just sell what is left for parts and pick up a new one. Sorry, but it is a 2003 that needs a motor. I suspect you are looking at about $3,000 with engine, parts, and labor. I have seen 2003's sell for what it will cost to fix this and some recently that sold for as much as $4,000. I hate it for you, but it might be time to walk away.

TownsendsFJR1300 said:

Please correct me if I'm wrong but can't the head be removed while the engine is still in the frame?

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If there is a hole in the piston it's pretty much game over. The only reason to try to fix a motor is because the owner knows the condition of the engine vs an unknown from a wrecked bike. In this case the OP doesn't know the condition of this motor any more than one out of a wreck. By the time the engine is out, head removed and all parts replaced, then flipped over and the cases split so the crank can be yanked you would be into it for more than the cost of a good used motor. For that matter, it may equal the cost of a used '03 motorcycle.

Buying used opens the risk for bent shift forks which really can't be easily checked before installing the engine. With an '03 - '04 there is an outside risk of buying a ticker. The starter should be good on a low miles engine. Check the stator wires to ensure it has a stock stator, if it has an aftermarket stator git it out and swap it with the stator from the bomb. Always do a leak-down test on the used engine before doing anything else. Adjust the valves and replace the CCT while it's on the shipping pallet.

Sorry to hear of your troubles.

You appear to have some serious issues with your motor. I believe more than likely it’s shot from what we can read/see so far. I like ionbeams advice.

BTW - When you did the CCT change, after installation and removing the T keeper for the CCT to let it go out, did you retract it again to make sure it was working properly? I also hope you made sure the CCT piston extended before installation.

You have molten metal in your plug. To me that means something gave way inside the cylinder (whatever valve, etc) and with heat and nowhere to go but up, your plug injected this molten or at least soft hot metal and it got worse with each piston TDC and fire to the point of failure.

My support to this is due to a totally chowed Jet-ski motor some years back. Yeah I know it's a 2-stroke. The lower end crank main bearings failed due to corrosion and when the ball bearings came loose from the race they went all postal inside the cylinder. The plug looked similar to yours but not quite as melty. My head and piston looked like they were shot peened real poorly and I had chunks of aluminum and steel inside the cylinder and plug. I needed all new lower crank with bearings and rods, new pistons, head, and bore job.

If it's a bent valve your head is seriously damaged if not totaled. The piston and valve are gone, and the rod may have issue as well. At this point it's probably used motor time

Good luck keep us posted on this.

The piston hit the valve,the two halves of the valve retainer released for a reason and the valve fell in the cylinder..Or simply the valve broke and fell..But why it happened only in one cylinder and not to all..?!Perhaps the valves and in the other three cylinders are bent..And what could cause a like this damage..?!vpantus said that everything was ok after the nstallation of the CCT..An opinion..Very odd story...

Ok folks... All he has to do to figure out if the plug was the WRONG one is read the stuf printed on it.

Also, Not to doubt your mechanical ability's but is it possible you may have installed a shim that cause that valve to come in contact with the piston.. The squish area is so miniscule.

It's possible that it wasn't an issue until things heated up...