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Had a really nice ride to my new office today.. about 17 miles each way from my house, gorgeous sunny autumn day: a bit chilly on the way in, but beautiful on the way home. Decided to push it a bit, and ran 55mph all the way back to town (~15miles) since the bike was running so well. Picture perfect sun on the horizon, flat farmland, etc.



Well, stopped at the grocery store to grab a few things, then jumped back on, and headed for the gas station on fumes. Filled up and started it only to hear a nasty clink-clink-clatter-clink noise. You know the type: the sort that makes your stomach sink into your knees as you realize the person at the pump next to you is staring and grimacing as if your tires just fell off and burst into flames.



The noise sounded like the chain broke and the links were rattling around, but the chain was still intact and I was still riding (about 75ft, total).



I shut it off immediately and rolled it to a gravel area just off the edge of the parking lot, then proceeded to give a quick visual inspection, and upon not seeing anything, pulled the cam chain cover and all looked well, there, too. With the cam chain cover off, I reached over and pushed down on the kick starter. It moved the cam about 1/8 of a turn and then seized solid. I mean stuck tight.



At that point, I called in reinforcements (my buddy and his daughter in his jeep) and we left the bike and went to retrieve my trailer, which incidentally had a flat tire. While waiting for him to arrive, I pulled the tank, spark plug, and valve covers: again, nothing of note: rockers moved freely and were in the expected position for where the piston was in the cylinder (not TDC..) Got it home in the trailer just fine, and have just started taking it apart. I started with the left (drive chain) side cover.



I can get it to turn back and forth with a ratchet/socket, but it binds in one spot, then I can turn it back the other direction and then forward again and it isn't bound, etc. It's kinda acting like the valves are bent, but I'm still not sure. I figure its time to stick the cover back on and check the cam chain timing marks if I can get it to rotate up to TDC. I was pushing the bike pretty hard in the wind, which I've done a few times without issue, but maybe the cam chain jumped teeth like crazy and the piston got into the valves.



Oil level was fine, filter was clean with fewer shavings than normal at oil change intervals, etc. I had noticed a noise in the last few hundred miles that I couldn't pinpoint.. I think the bottom end just found it for me.



Anyone have a creative method to pull the rotor/flywheel without buying more tools?
I don't see how I can make my big 2 jaw puller work, and if I can't, I'll start tearing the head/cylinder off and see what I can find there.



Sad day.. but the good news is: it was an absolutely amazing last day on the bike, if its done for the season.



Edit: so.. uh, bigger bore and hot cam time?
If I'm gonna break critical internal engine parts twice in one season, I at least ought to have a great big smile and a reason for it.
 

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Rear axle bolt will pull the flywheel.
 

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Had a really nice ride to my new office today.. about 17 miles each way from my house, gorgeous sunny autumn day: a bit chilly on the way in, but beautiful on the way home. Decided to push it a bit, and ran 55mph all the way back to town (~15miles) since the bike was running so well. Picture perfect sun on the horizon, flat farmland, etc.



Well, stopped at the grocery store to grab a few things, then jumped back on, and headed for the gas station on fumes. Filled up and started it only to hear a nasty clink-clink-clatter-clink noise. You know the type: the sort that makes your stomach sink into your knees as you realize the person at the pump next to you is staring and grimacing as if your tires just fell off and burst into flames.



The noise sounded like the chain broke and the links were rattling around, but the chain was still intact and I was still riding (about 75ft, total).



I shut it off immediately and rolled it to a gravel area just off the edge of the parking lot, then proceeded to give a quick visual inspection, and upon not seeing anything, pulled the cam chain cover and all looked well, there, too. With the cam chain cover off, I reached over and pushed down on the kick starter. It moved the cam about 1/8 of a turn and then seized solid. I mean stuck tight.



At that point, I called in reinforcements (my buddy and his daughter in his jeep) and we left the bike and went to retrieve my trailer, which incidentally had a flat tire. While waiting for him to arrive, I pulled the tank, spark plug, and valve covers: again, nothing of note: rockers moved freely and were in the expected position for where the piston was in the cylinder (not TDC..) Got it home in the trailer just fine, and have just started taking it apart. I started with the left (drive chain) side cover.



I can get it to turn back and forth with a ratchet/socket, but it binds in one spot, then I can turn it back the other direction and then forward again and it isn't bound, etc. It's kinda acting like the valves are bent, but I'm still not sure. I figure its time to stick the cover back on and check the cam chain timing marks if I can get it to rotate up to TDC. I was pushing the bike pretty hard in the wind, which I've done a few times without issue, but maybe the cam chain jumped teeth like crazy and the piston got into the valves.



Oil level was fine, filter was clean with fewer shavings than normal at oil change intervals, etc. I had noticed a noise in the last few hundred miles that I couldn't pinpoint.. I think the bottom end just found it for me.



Anyone have a creative method to pull the rotor/flywheel without buying more tools?
I don't see how I can make my big 2 jaw puller work, and if I can't, I'll start tearing the head/cylinder off and see what I can find there.



Sad day.. but the good news is: it was an absolutely amazing last day on the bike, if its done for the season.



Edit: so.. uh, bigger bore and hot cam time?
If I'm gonna break critical internal engine parts twice in one season, I at least ought to have a great big smile and a reason for it.
Sorry to hear about your problems but it is good to hear that you can end the

season with a positive attitude. I would have thrown a hammer through the wall

of my garage and kicked the dog across the street. Just kidding, good luck with the repairs.
 

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Discussion Starter #5
Reviving an old thread, since I finally scrounged up a few $ to buy the gaskets and such to reassemble the bike:



Good news, everybody: the TW lives to ride another day!



Parts showed up at 17:15 today, I was out in the garage by 17:30, took me 30mins to scrape the old base gasket off the bottom of the cylinder (wow that thing had turned to cement!), and was ready for reassembly. 4hrs later, after putting the kids to bed and chatting with my wife, I finished up and filled with oil, turned the gas on, and kicked it to life!



Bad news is, its really cold out and I couldn't get the airbox boot to fully seal around the carb, and it appears to be a very bad leak. That, combined with the very cold dense air, the bike is now running *VERY* *VERY* *VERY* lean: within 3mins or so of running just above idle, the header is getting red hot. Therefor: I only ran it for about 4.5mins
The important thing is: now I know it runs.



Now, for the really unfortunate and pretty irritating part: the post-mortem. I even took pictures, 'cause everyone loves a good carnage shot.



During teardown, it wasn't immediately obvious what had happened. Upon closer inspection, the engine was *not* seized; but in fact it would turn backwards for a bit, then seize in that direction, but you could turn it forward again for a bit: the number of rotations was small, but seemingly did not follow a pattern.



I had the left side case and rotor off, starter gear out, cam chain cover off, tensioner out, etc. Nothing really seemed to be outwardly wrong with those pieces, so I tore the head off, then cylinder, pulled the piston (unnecessarily, I later found, but good for diagnostic reasons). After getting the cylinder off, I pulled the front cam chain guide out to inspect it, since I was that far (hadn't had the cylinder off before, but have had the head off to deal with a busted up valve head earlier in the year). Once I did that, I saw underneath the lower cam chain sprocket a small loose piece:











A bit odd: its a chewed up and spit out metallic comma.



Turns out, its a dowel pin from either the head or cylinder that fell down in the cavity at some point when the motor was apart. The scary thing is that I don't know if *I* screwed up and dropped it in, or if someone previously did!
If I did it when I had the head off fixing the valve, I somehow didn't notice a missing dowel pin, and I'd put around 1000 miles on the bike since that repair. If the previous owner did it, who knows how many miles its been floating around in there!




The dowel pins are split lengthwise, and apparently this one got chewed on enough that the split became pronounced, caught on something and became a comma shape, wedging the cam chain and causing my "seized motor", and an abrupt end to said riding season.



I have all new dowel pins now, new base gasket (unfortunately bought the 2009 one instead of 2010: I screwed up and hope I don't pay for it later), new head gasket, and some o-rings that I wanted to replace while I was in the region.



Now to fix the lean condition and test that tire chain out...
 

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Too bad an X-Ray, Catscan, or MRI won't work when looking for internal problems. Enjoyed reading this thread, hope I don't have similar problems, and am glad you've been able to figure things out.

Thanks for sharing the good, bad, and ugly. We all learn something whether we know it or not!
 

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Appreciate the feedback and great pictures. It is always nice when someone goes "full circle" when dealing with a problem. Not only do we hear of your problem, we see the cause and the solution. Seems the reminder here is that we need to remain vigilant, makeing sure everything gets back to where it belongs.



Not sure about the rest of our 'senior' wrenchers, but I am troubled by what I sometimes 'forget' when working on a project. One time when working on the front-end of my VW, I left the lug bolts on one wheel finger tight. I was lucky to realize my oversight before I reached the main road.



Use care my Friends. Check and double check before you call the job done.



Gerry
 

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Read and follow instructions. One step at a time. Take pictures before and after each step. Lay out parts in the order and orientation removed. Take more pictures. Tools not in your hand are back in the toolbox. Use the best parts available--the cheap stuff won't last.
 
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