Hi,

I was testing my 59 plate tenere, after fitting kev mod, riding slowly in first when metalic sound from the engine, rear wheel locked up and engine stopped. Pushed it home, not easy, have taken the cam cover off thinking cam chain may have broken but appears ok. The engine will not turn over on the starter but will turn one full revolution using a socket on the crank shaft bolt. Engine comes to a very solid stop afer one revolution. Bike will still select 1st and 2nd gears.

I have owned the bike 7 months, 37,000 miles, previous owner did majority of the mileage and serviced as recommended. I have cover about 2000 miles mix of commuting and greenlanes.
Any suggestions what it could be?

Many thanks

Before we jump to any conclusions...

Could you see if you can turn the motor (by hand on the crank nut) more than one revolution with the clutch disangaged (lever pulled in).

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Hi,

Just been fiddling a bit more not done anything specific put it in and out of gear a couple of times. The motor will turn several times with the crank bolt clockwise, with a werring sound, but comes to a sudden stop, within a turn, when rotating anti clockwise.

Pulling the clutch in appears to have no effect.

thanks for the quick reply.

update,

doesn't matter how many times you rotate clockwise it will always stop within a turn in the same place when rotating anti clockwise.

For info: engine number M311E0008273

Remove the spark plug and try turning it over.....

Have you checked your radiator and sump levels..?

Hi,

Spark plug is removed and all fluid levels are good.

thanks

Hi I had a similar problem years ago on a Yamaha V twin it turned out to be the sprag clutch for the starter which would allow the engine to turn one way and jamb up the other way.Sorry I don't know if the Xt660 is a similar layout. The sprag had worn through it's casing. Steve.

Hi Steve,

Thanks for the reply. Yes the starter clutch is the area i'm thinking also. I have drained the oil and all very clean with no signs of anything on the plug. Starter removed and its still the same i have taken the valve covers off and all looks ok moving when rotating the one way but still locks up when you reverse the rotation. I have taken the side casing off to expose the magneto just need to get a puller.

Many thanks for the advice.

Found the problem, a piece of 4th gear dog has snapped off. Is this the gearbox failure issue that the 59 plates have suffered from?

seriously gutted to read about your bike julian, I am away until Wednesday night but if you need my trailer, I can sort acsess for you.
tomasz had a gear box failure on his xt660z (I dont know the year though) and I am pretty sure he replaced it with a xt660r engine.
I can give him a email when I get back he maybe able to offer some advice.

rog

Thanks Roger, looking into gear ratios etc to check all engines are the same. Enjoy the rest of your holiday.