The design of an XJ Yamaha requires the motor to be pulled and the cases split to replace the starter clutch. Anecdotal stories exist where sufficiently skilled mechanics have been able to go I through the alternator housing with very long pliers and screwdrivers to do the job in-situ, but the details on how to do this are so chilling I decided it was better to go the whole route, since I was pretty much 100% guaranteed to drop something inside the engine anyway.

The motor was a mess. The whole back of the engine was caked in oil and dirt, which had leaked out from the pressure pipe leading to the carburettors. The XJ has its turbo mounted down low, behind the crankcase, which allows oil to gravity feed into it when it is left sitting for a long period of time. There is a check valve mounted at the front of the engine where the oil feed line taps into the main oil gallery, but it tends to be problematic in operation after a while, as the ball and seat inside it wears. The turbo itself has seals on the shaft which resemble small piston rings, which require boost pressure for sealing, so they do little to stop oil from leaking into the turbo compressor housing when not running, which leads to smoky start-ups. The bike actually burped about a shot-glass of oil onto my leg when I removed the rubber air inlet hose during the initial teardown…

Summer was passing by, I had parts everywhere in plastic bins and in the trunk of my car, there was a stink of chemicals and gasoline everywhere, and I had only an old television stand to use was a workbench. It was either staggeringly hot and humid while I was working, or I was scrambling to collect all my tools and parts when the clouds opened up.

I confess to calling the local breakers to see what they would give me for the bike in parts, but it turns out they would have charged me to come collect it! Talk about falling from grace.

I bit the bullet and completed the repairs. Lifting the 650 lump back into the bike showed me where much of the bike's mass came from. It's a heavy old motor. I am glad to say the repair was a success. The engine started fine, didn't self-destruct, and ran reliably the rest of the summer. So for my troubles, I had an old, portly, poor handling, peaky turbo bike, that no longer buzzed and started reliably. I dared not add up the cost of the repairs, since I'm sure it would have given me palpitations. I rode it for the last two months of the riding season and parked it.

---------

Next episode: so was Roger going to live happily ever after with his XJ turbo?