DRive Shaft snatch

Technical All CARC models
1

Hi,

i may have already posted something about this, im new to this site and havent mastered it yet, but is it common for CARC systems to ‘snatch’ ? i mean, on a light throttle when moving on after slowing down in 1st, the my GRISO sometimes/always lurches forward, its quite unsettling. i suspect the UJs although 2008my with 17k miles. it could be anything else in the drivetrain but hopefully not. thanks

2

The torque arm bushes can cause some snatch and can be easily replaced with updated rubber bushes but I’m not sure if that’s what your experiencing.

3

Thanks, I’ll look at those, check if that’s the issue.

4

My GRiSO (28 to 43,000 miles did not snatch after i first synchronised the throttles. If they don’t pick up together that can cause lumpy slow running and delayed pick up which can really upset the drive line shock absorber (which is a long bonded rubber sleeve between the inner and outer parts of the drive shaft)

5

I was gonna suggest that earlier that the origin might be fueling. Lumpy response at the front end will result in lumpy jerks at the back?

1 Like
6

I would look to see if you have if you have to much free play on the twist grip, this can give a snatchy condition.

7

Thanks for your message, the free play is minimal. I feel that the issue is in the drive shaft. On a paddock stand the rear wheel turns about 3” on the circumference with a slight clunk turned forward not so loud reverse. Now, those who are familiar with the CARC system may say “that’s normal, they all do that” which is the reply I was hoping to get, I can live with that, although I wish it was less. Anyway, it’s off for the MOT at Newcombes in 2 weeks, if it’s too bad I’m sure they will tell me.

8

I recall that it was around the 6 to 8cm but as i sold the GRiSO i cannot go measure it.

HAve you got vacuum gauges and Guzzi Diag and the plugs to do a service on the bike? Setting the throttle synchronisation is very rewarding on all big twins as you spend so much time on relatively small throttle openings

9

So that delay in the power transfer (like a very slack chain) didn’t bother you too much ? How long did you own it ? Did you have the same experience with other shaft drives ? My V50 had none that I noticed.

10

When the pick up was smooth and strong the back-lash wasn’t a problem. When the chokes were out it got a bit juddery in town.

Relying on my memory and it may have been less than 6cm, as i say i have not got a CARC to measure now and i am just remembering from re-installing the rear wheel.

Would be interesting if another CARC owner couild measure