1955 18CS Drivetrain Rattle

itma · Post by **itma** » Mon Sep 11, 2006 11:05 pm

I said rattly not ratty

unless their teeth were loose of course?

TommoT · Post by **TommoT** » Tue Sep 12, 2006 12:10 am

quote:
Hi Folks!
Ive just put my bike together with the engine totally restored, except the cams...
The drivetrain rattles like ....

Keje,Sweden, 1955 18CS with SH-cams

Have you checked the primary chaincase inspection cover? If the locking strip is not vertical it may touch the primary chain and cause an unusual amount of clatter. (don't ask me how I know!).

Good luck!

Biscuit · Post by **Biscuit** » Tue Sep 12, 2006 12:41 am

Only with a very loose chain Tom. If 'busicuit' is intentional Roger then woof woof. Perhaps I couldn't hear your engine over the clatter of mine.Edited by - Biscuit on 11 Sep 2006 11:47:15 PM

TommoT · Post by **TommoT** » Wed Sep 13, 2006 3:56 pm

quote:
Only with a very loose chain Tom. If 'busicuit' is intentional Roger then woof woof. Perhaps I couldn't hear your engine over the clatter of mine.Edited by - Biscuit on 11 Sep 2006 11:47:15 PM

Must have had a loose chain as well, amazing how many faults you can have on just the one bike! But wauw, my engine must be fast with all the rattle going on down there below the tank! (ref. itma!)

and listen carefooly Roscher, I wil tel yu thees onli wonse: its Bizcute and no Busicuit...! (just testing my new Frenz spell checker!)Edited by - TommoT on 13 Sep 2006 2:58:46 PM

Biscuit · Post by **Biscuit** » Wed Sep 13, 2006 4:04 pm

Tom, your English is excellent, but I'd leave French alone if I were you. Besides, your native tongue and English is all you will ever need!

keje · Post by **keje** » Wed Sep 13, 2006 9:32 pm

Roger

I know that there has been no checking for end float on the camshafts as told by the restorer (I asked him to do that, but he could not manage it), a cause for the rattle perehaps.

Yes there is a typical double "click" on the inlet valve and also some noise on the exhaust when turning over, cold or hot.

All the best
Keje.

Biscuit · Post by **Biscuit** » Thu Sep 14, 2006 11:06 am

While its true you have to split the crankcase to move the camshaft inner bushes, there are shims that can take up endplay. The double click I would say is backlash between the cam wheels and the half time pinion as the the tappet rides over the peak of the cam.

keje · Post by **keje** » Thu Sep 14, 2006 10:34 pm

Biscuit,

i think you have the right point. The double click is backlash between the cam wheels and the half time pinion. I beleive there is not mutch to do about it than to get a new set of cams and a fresh pinion gear.

Chiming the cams would not have affect on the noise.

Still im wondering if anyone in the club have tryed new cams and how they sound compared to some with 50-years of hard work in them.

Regards
keje?

Biscuit · Post by **Biscuit** » Thu Sep 14, 2006 11:06 pm

Never changed cams in a single, but have just replaced the gear train in a twin and it made a lot of difference to the noise level. If you haven't run the engine a lot, you may not need a new halftime pinion

jim501 · Post by **jim501** » Fri Sep 15, 2006 11:02 am

quote:
With the glorious exhaust note produced by SH cams, surprised you can hear anything....

Oh, Yes !!!

The G80CS in the Gold Star frame. SH cams, GP carb and open reverse cone megaphone. Apart from the sound it had an interesting habit of crackling and blowing flames out of the exhaust on the overrun.

Nowadays you'd probably get fined, whipped, and banned for that sort of stuff.

Oh, happy days.

Then I got a mortgage and some children and had to buy a sensible car.

cheers
jim