Friday, 25 August 2017

Project "pretty one" - digging into the engine and finding...

... not much. Except for a stuck oil-ring and that the two inlet valves have touched the piston and are not bent. Which in my book is enough to explain the quite stunning "I am a two-stroke"-charade of the old XT. 😉

Nothing much to see and find on the very top of the engine. Cam and rockers still look like new, but getting the valve cover can be a bit of a pain, if you forget about that one bolt that sits between the two ears of the head-to-frame-mount.

Once the head was off there wasn't any damage immediately visible. It was quite a bit oily, yes but at first glance all good.

Then I had a look at the piston and was stumped. When putting the engine together last time, the valves must have just touched the piston. 

Which was proved after some closer inspection of the two inlet valves. 

The standard leakage test revealed marginal leakage after about ten minutes, but nothing that would worry me or indicate a bent valve. After all this engine has done 42,000km so far. 

Heaps more annoying: The oil-control-ring is somewhat stuck in its groove and there's also some light scoring on both the piston and cylinder. 

Next time I'll brake out the subito and measure both cylinder and piston and see whether we can just sneak in a set of rings and do this on the cheap or whether we should go all in and get the cylinder bored and fit an oversize piston.

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