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Bike locked up but engine not seized Need Help :)

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I took the motorbike down to the local motorbike mechanic last week to get the valves checked and a service. They had to replace 3 of the shims on the intakes valves and oil change and it was happy days.

Been riding all day no worries in till this afternoon when whilst changing and just hanging onto gears that it would more or less cut out and lock up. This is happening at quite some speed so it's a bit hairy. I noted that whilst that the bike was in neutral that i couldn't crank it over on the e start and the kick start wouldn't budge. I managed to get fine again by rolling it into gear and I was able to get it to go ago.

I was ridin it just up and down the dirt road trying to find out what was wrong when all of a sudden it locked up

Basically whats wrong is I have no problems selecting gears. The clutch works great. But the kick and e start won't do shit & and i can't roll start it. It's like Their almost seized it won't budge.

after some fiddling around this is my summery

The bike wont crank over on the starter or the kick start

There is nothing wrong with the starter

Bike goes in and out of gear still as normal (But obviously won't push start)

Nothing wrong with the clutch

I can turn the engine over using a socket on the crank shaft (no weird noises there)

The valves are perfectly aligned & have 3 new shims

The timing chain still has plenty of tension and hasn't skipped any tooth's

Any help or suggestions :smirk:

P.s sorry for the long story but more info is better than less.

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Not sure if this is your problem but I had an 03 YZF basket case I bought locked up. The original owner pulled the head and cylinder and suddenly it would turn over fine. It turned out to be the rod bearing. If you spun it without the piston you could feel it intermittently locking up. Now that was just my case. Have you dropped the oil and looked at the filter yet? May be some clues there. I'm not sure about the electric starter but when you turn the crank with a socket, you are basically turning everything the kick starter would turn so not sure about what being able to turn with a socket is telling you. After the oil and filter check I would pull the right side cover next to investigate since that's basically where everything is - clutch, couterbalance shaft and gear, oil pump, etc. Clay

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You said that you can't push start it. Does that mean that the engine won't turn over when you try, or just that it won't fire? If it's because the engine won't turn over, can you turn over the engine using a socket on the crank when it's in gear? If not, try to rotate it the other direction and see if that frees up anything.

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You said that you can't push start it. Does that mean that the engine won't turn over when you try, or just that it won't fire? If it's because the engine won't turn over, can you turn over the engine using a socket on the crank when it's in gear? If not, try to rotate it the other direction and see if that frees up anything.

I've just tried cranking it the other direction and it would turn over with the kick start and e start but only like one turn (if that makes any sense)

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Maybe a broken shift fork has it in two gears at the same time. It would still seem to shift fine as the drum indexing mechanism would still be working normally. Can you put in it neutral so the back wheel will spin freely? I'll admit this is a long shot. I don't have that much experience with these particular bikes to know if shift fork problems are common or not - I'm thinking not but it's an idea. Clay

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Not to sure on the shift fork but after a bit of investigating I am able to do this.

If I put the bike into a high gear 3-4-5 I can move the wheel backwards whilst it is in gear. If I go to move it forward it will lock up.

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I took the motorbike down to the local motorbike mechanic last week to get the valves checked and a service. They had to replace 3 of the shims on the intakes valves and oil change and it was happy days.

Been riding all day no worries in till this afternoon when whilst changing and just hanging onto gears that it would more or less cut out and lock up. This is happening at quite some speed so it's a bit hairy. I noted that whilst that the bike was in neutral that i couldn't crank it over on the e start and the kick start wouldn't budge. I managed to get fine again by rolling it into gear and I was able to get it to go ago.

I was ridin it just up and down the dirt road trying to find out what was wrong when all of a sudden it locked up

Basically whats wrong is I have no problems selecting gears. The clutch works great. But the kick and e start won't do shit & and i can't roll start it. It's like Their almost seized it won't budge.

after some fiddling around this is my summery

The bike wont crank over on the starter or the kick start

There is nothing wrong with the starter

Bike goes in and out of gear still as normal (But obviously won't push start)

Nothing wrong with the clutch

I can turn the engine over using a socket on the crank shaft (no weird noises there)

The valves are perfectly aligned & have 3 new shims

The timing chain still has plenty of tension and hasn't skipped any tooth's

Any help or suggestions :smirk:

P.s sorry for the long story but more info is better than less.

Put the bike in neutral. Remove the spark plug. The crank should now turn freely. If not, you have either a bearing or piston seizure.

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It is sounding to me like it may be something jamming in some gears somewhere. Most likely by the clutch or in the tranny. Time to start pulling it apart and see what you find.

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It is sounding to me like it may be something jamming in some gears somewhere. Most likely by the clutch or in the tranny. Time to start pulling it apart and see what you find.

I've had several people suggest the pulling the clutch out and having a look at the primary gear & inspect when there kick start engages to see if its stuck more or less one way.

I am wondering that if i remove the kick starter and re-install the clutch if that will have any effect on the bike. (been that i have e start and i don't think i've ever had to kick it over :smirk: )

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My guess is over torqued cam caps. You did just have them serviced and when they get warm they seize. They only require 7 ft/lbs of torque which is barely more than finger tight.

2nd guess is you've got tranny teeth wedged between your stator and your flywheel.

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Have you dumped the oil yet? If it is a tranny tooth or something jamming inbetween gears then you will most likely have some debris in your oil and/or oil filter. Regardless, it sounds like you are gonna have to start tearing it apart.

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Not to sure on the shift fork but after a bit of investigating I am able to do this.

If I put the bike into a high gear 3-4-5 I can move the wheel backwards whilst it is in gear. If I go to move it forward it will lock up.

Will the engine turn more than one revolution when you rotate the wheel backward? If so, I'm inclined to think that you have a broken gear tooth trying to wedge between the flywheel and stator. The gear that drives the water pump is fragile and occasionally breaks. Pieces are free to make their way through the crankcase and into the flywheel side. They can create all kinds of mischief there playing with magnets. It's surprising what you can find clinging to a flywheel when you remove it.

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Only b/c the valves were just serviced, maybe the intake valve bearing retainer clip fell into the cam chain well unnoticed during the cam installation and has worked it way into the gear box, stator or clutch areas.

That clip is ez to loose.

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Like Big daddy said except it's called the CAM bearing retainer clip and it could be either intake or exhaust, those can jam the flywheel easily as others suggested.

When torquing cam caps stay about 5-7in/lbs less than spec.

Flat spot on big end bearing can lock up forward motion, usually rolling it backwards in gear will free it up for another ride session til it locks again.

Pretty much ANY loose metal in the bottom end can cause your symptoms, but it sounds like the shop dropped something down your cam chain passage and the retainer clips are the prime suspects...or a shim.

Like suggested, drain the oil, look for metal, then pull both case covers and the flywheel and inspect both sides for foreign parts, might have to pull the clutch too but you can probably inspect the right side without doing that, hopefully you won't have to split the cases to get at what the problem is.

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