Tresette Sprint terrible noise on over-run...primary gears?

Singles built before the Lambertini era
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Ramsey
Posts: 3
Joined: 25 Jan 2017 19:44
Location: Ramsey, Isle of Man

Tresette Sprint terrible noise on over-run...primary gears?

Post by Ramsey »

Hi there,

Recently purchased a 1958 Tresette Sprint which was mainly assembled when bought but not running.

I have now re-assembled the machine and the engine sounds wonderful and starts easily. After checking everything over I took the machine for a test ride and found that there was a very loud whining noise on de-acceleration. The noise is also present when you initially let the clutch out in first gear but not so loud as when on over-run. I suspect that the problem is the helical primary reduction gears as there is quite a lot of backlash between the clutch bell and the camshaft gear.

The strange thing is there is no noticeable noise when the bike is not in gear or when accelerating in gear. I have removed the clutch completely and checked the thrust washer and that there is no end float or mis-alignment of the helical gears so if anybody has experienced this before or can advise me on a remedy it would be much appreciated.

Many thanks

Jonathan
bellinger3387
Posts: 5
Joined: 04 Oct 2016 17:20
Location: Brenchley, UK
Location: Benchley, Kent

Re: Tresette Sprint terrible noise on over-run...primary gea

Post by bellinger3387 »

Jonathan,
Not much help to you I know, but I have what appears to be an identical noise on my 1962 Tresette, bought last year.
I too stripped down all the primary drive and found nothing obvious, though I also had a badly dragging clutch caused by an additional plate (!!) and odd length clutch springs. NLM supplied a set of used but sound springs/cups and it now works fine. I guess I'll just have to live with the noisy primary drive. Hopefully someone else more knowledgeable than us may have an answer.
Regards, Keith
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