Hello all. I know this web site is a great source of help and thought I’d share some information. It’s a bit of a long tale and I apologise.
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I’ve owned a 2009 Tenere for 4 years, purchased with 6000 miles and now at 29.5k. I’ve had a love hate relationship, nearly px’d it 5 times. For the last 15k-ish it’s had Kev’s fuel mod, O2 mod, DNA air filter, GPR exhausts, a replacement stopper arm,(part 5JW-18140-00) and the final drive nut checked and re-torqued, plus other bling like braided brake lines, 3 wavy discs, AS sump guard, Ohlins front springs, Hagon rear shock (both 500 miles old), short levers, headlight protector, centre stand and various farkles.
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A few days ago, whilst decelerating in third gear towards a roundabout, I felt a bang in the right footrest area and thought the front wheel had chucked up a rock, that I hadn’t seen or felt. I stopped before joining a motorway, turned off, had a look underneath at my sump guard and saw no damage / impact marks. I started up and rode off up the joining slip and felt the same bang whilst accelerating in third gear but this time the bike cut out. I coasted to the hard shoulder and tried a re start but without starting it as it sounded awful on the cranking The recovery agent was called out.
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At home I put the Yamaha Fi diagnostic tool (part 9089003182 https://www.cmsnl.com/products/fi-di.../#.WjahoNVl_rc ) into the loom. Great bit of kit but sent me on a wild goose chase because I misinterpreted the first code D01 (throttle position sensor) code 16 which is a faulty TPS according to manual, leading me to initially believe I had a fuel flow / timing issue but in fact the code 16 turned out to be the angle of the closed throttle because as I turned the throttle the diagnostic numbers raised to 97 which is the angle of a fully open throttle TPS. I measured the voltages on the TPS and they were correct according to manual, (yellow wire at the ECU as the back of the TPS is hard to get to)
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Next, the line of least resistance checks lead me to a compression test next. 20 psi on a cold engine (I dared to crank it over although it wouldn’t start to get a warm reading-should be 85 ish). Poor compression? (Is this an auto decompression reading - not sure?)
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So I set the cam and crank at TDC on the “I” marks and measured the valve gaps. All middle of spec results. So thinking poor compression (albeit cold engine) and closed valves may be serious. I took the airbox out (after the swing-arm, rear undertray and shock) and then the throttle body, (checked the injector gave 12 Ohms - perfect), plus the exhaust header pipes came off. I then injected smoke into the cylinder head via the spark plug hole, using a compression test fitting in place of the spark plug and attached plain tubing. The smoke came out of the exhaust ports and the inlet manifold. I think I’m now having to take the engine out and head off. Have I got burnt valve/s seats (fueling too lean) but the diagnostic tool showed me Kev’s fuel mod was working fine because when I turned Kev’s mod dial I could see code D05 (air intake temp) changing as designed by this mod. I’ve had the fuel mod dial set at 6pm position. My ambient air averaging 20 degrees C on rides.
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So, engine came out as per manual procedure but was a bit tricky with frame clearance issues / ignorance. Benched the motor and head off. I placed the upright head on paper towels on a workbench and filled the exhaust and inlet ports with fuel onto the top of the valves as they rested closed. There were significant round pools of fuel on the towles. Definitely poor valves seating although the valve gaps had been checked at the appropriate mileages and at the time of the test the rocker arms could be ‘rattled’ and gaps were correct. Poor fuelling / valve timing / closures / trapped debris? Using a home made slide hammer, (6mm coach bolt/rod and a heavy socket), I pulled out the rocker arm shafts, (they’re internally threaded to use the slide hammer), and rockers.I then took the valves out and the mating surfaces looked stained but not pitted and no debris. I know eyeballing this is not accurate but there was no visible damage or burn ‘witness marks’ on the surfaces but they definitely failed a smoke and liquid seal test at TDC.
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Whilst I’m with the motor on the bench I took off that right side engine case again and checked the final drive nut and stopper arm ……………..and there it was, a large chunk of gear pinion. Game over!.
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Using a magnetic pen I pulled out more shards of shrapnel from the sump area. Conclusive enough for me that the gear box had crashed a gear and that was the bang I felt on the move, whilst being in 3rd.
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My riding style is gentle to firm on occasions but never aggressive. The bike has been on gravel and shale trails 10% through of my ownership but never overworked and hasn’t seen the red line or even more than 75mph. The bike is serviced on time, probably over serviced with oil and filter every 3000 miles, s/arm out, headstock out every year and so on.
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So, in conclusion, I’m now looking for that elusive replacement engine, whether it be from an Aprilia, MZ, or any XT 660. I have seen a few on ebay.com
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For the benefit of those who collate data. My engine number starts, after all the zeros, with a 7 and is from a 2009 production / Italian chassis identification numbers.
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As for the valves passing smoke and fluids through when closed, I can only guess that was another developing problem, maybe, and in my case correct gaps don't mean the valves mating faces are actually closed and sealed. I'll definitely be doing compression tests at the time of valve clearances to verify they're sealed shut and not just rely on "correct" gap clearances.
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Anyways...hi, once again..and apologies if my intro crosses into other thread territory straight off the bat.