Triumph Twin twinshock trials bike.

[earthmover]

As soon as I took the cylinder head off, the engine freed off. The broken bits were sat on top of the piston, stopping it from moving.



Thankfully it wasn't actually running when it happened, or the damage to the rest of the motor would have been substantial!




Cause, or effect? The million dollar question. (well maybe about £350)



Nearly all the bits.



Who knew that learning to use chopsticks would come useful for more than Chow Mein?



Last piece!



Timolgra sent the badge pic, sympathetic as ever.
Mark

 

[earthmover]

I decided that a new source was necessary, I've been let down twice now. A third time will not be an option.
So scouring the internet we go, until after a number of red herrings, I found a re-con barrel, complete with new pistons for a few hundred quid. This from an engineering firm, with a warranty.
Probably not worth the paper it's printed on, but at least shows willing.
With the barrel in my sweaty mitts, I examined it thoroughly to satisfy my (untrained) eye, and checked it was actually the same size as the supplied Std pistons and rings.
Everything seems in order, so I set aside some garage time to rebuild the beast.
Mark

 

[earthmover]

One thing I had been advised to do this time was to fit a thick copper base gasket, to try and lower the compression, so that in turn I can lean off the mixture slightly. This will hopefully give me the same state of de-tune that I'm used to, without as much fuel washing the bores and shortening piston ring life. Sounds feasible.
Mark

 

[earthmover]

A couple of bits of wooden batten under the pistons to stop them dropping back down, and a pair of ring compressors in place ready to lower the barrel.



Which was a lot easier without the lip in the original barrel! Refit the 8 nuts and tighten down, bearing in mind the thicker base gasket.
Mark

 

[earthmover]

The cylinder head and rocker boxes back on, adjusted the valve clearances which again needed to take the extra height into account.


Refit the carb, and then wrestle the exhaust back on. I won't bore you with the tale of why it wouldn't run properly, and how I broke my (cheap nasty) gear puller trying to take the ignition rotor off so I could reposition it, and how it was in the right position in the fist place, and that it was because "someone " had adjusted the valves clearances completely wrong. That someone gave himself a very strong talking to, after wasting time and effort that he didn’t need to, if he had only done it right in the first place, and having to buy another (cheap nasty) gear puller, and giving his mates earache as to why it wouldn't run properly?
No, I won't bore you with that.
Mark

 

[earthmover]