Daytona 675 Alternator Rattle

Emyr Meek · May 22, 2021

Recently bought a 2009 Triumph Daytona 675, and when starting the bike up, a rattle could be heard from the LHS of the bike - putting an ear to the alternator cover, I could hear that the rattle was coming from within. Took the alternator cover off after buying the bike, everything looking good, nothing loose to do with the alternator. I then removed the gear (arrowed) that drives the crank from the starter motor. After bump starting the bike - the rattle was gone! Therefore, I presume that the issue is to do with excess float around the gear, which then rattles at it rotates. So my question is this - has anybody come across this problem before? And also with regard to a way around this issue - I wonder if the placement of an appropriate thickness of shim would solve the problem?

Thanks for accepting me to the forum - can't wait for some good weather to get out on the bike!

Yorkshireman · May 23, 2021

I’m guessing by the lack of replies Emyr that no one has had the same problem. Does the gear rattle all the time or just when the starter is engaged? Maybe you could install a thin shim like you suggest but be careful that you don’t cause the gear to stick and make the starters job harder or the gear to rotate with the engine after the starter has done its job

Bolosun · May 23, 2021

I would check the parts fiche as well. When I was playing with the rotor on my SV, there is a washer and spacer in there that has to go in the correct order. Maybe it has the same and is fitted wrong or missing a bit.

Emyr Meek · May 24, 2021

Thanks guys. Strange that nobody has come across this before! Maybe a one off thing. I put the gear back in, and placed the cover back on without the gasket - started the engine for around 10 seconds - noise gone. The gasket is around 0.5mm thick where it's compressed, so maybe this introduces the excess play. Anyway, new gasket on the way, and some 0.1 and 0.2mm shims. If the new gasket is thinner than 0.5mm I may be able to get away without any shims, however may put a 0.1 or 0.2mm shim in there and see how it goes!