Today I got to play on a customers 851 tricolore. The fuel pump ordered finally arrived and I replaced the pump.
Now originally the bike came in for a knocking noise in the engine. A mechanic looked at the bike (now no longer working for the shop.), listened, took off the alternator cover to check the alt nut, rotated the engine to see if there was anything else. He couldn't find anything so put it back together and told the owner he couldn't find anything.
The owner took the bike and made it 30km before the bike stopped and wouldn't start.
Bike sent back to shop. I had a look and started to test everything and have a play. I got to the fuel filter and found it full of shit. Some of it shinny, some of it black plastic looking stuff. It was pretty obvious the fuel pump crapped out or was about to crap out big time.(somebody had been inside the pump before). I slaved in a pump but still no go. It would sort of run, but only on wide open throttle, and without much power. Next I checked the phase and timing sensors. One seem to be low on resistance so it was ASSUMED that was the issue, so another sensor was sourced. All the injectors we cleaned and checked for continuity and resistance. Ignition modules and computers were slaved in to rule them out. Work stopped while we waited for the pump.
Pump replaced and sensor installed. Bastard thing still doing the same. Then the kill switch starter button died. Had a replacement. hoped that was the issue. No.
Ok what the story. Bob the boss called in. Back to basics. Yes I have spark. Yes I have fuel pressure. Yes I have fuel flow. TPI working and set correctly. OK what was the original issue. Knocking. Cam covers off again. Cams and belts alignment correct. Jack shaft not loose. Ok Alt cover off. Nut still in place. Look back at cover. Holy shit. How did the mechanic miss that. The water pump bearing and a bit of the cover was sort of worn away. The fly wheel had moved, ah knocking then no knock as it had worn enough away. Ok why? Pull off Alt rotor, pull off fly wheel. Plop tink tink tink plop tink, as the screws that hold the starter flange to the flywheel fall out, all sheared. The reason the bike stopped. The fly wheel had rotated on the flange. Timing out of limits. Why the screws had loosed off I have no idea. I suspect a sprag replacement not done properly.

The moral of the story. If you hear something knocking. Then there is something wrong. Keep searching until you find it. Even if it stops knocking.
Second don't trust the work of a mechanic you don't like. I spent bloody ages checking everything on the assumption old mate had done his part.

The bad news is we can't charge the customer, The good news is I got to do a complete elect system check on his bike and componants and its all good. So he has to be happy about that especially as it is for free.

Pity I lost the new rh switch block I was eying off for my spares collection.🙁

Griff