Topic: Gears not selecting - Nova close ratio gear cluster

[Phil]

Can anyone help please? I'm putting together a race engine fitted with a (new) Nova close ratio gear cluster. I'm having trouble selecting the gears now. I suspect the shift drum is causing the problem, but maybe not. The cases are F2. The gear cluster was made for the F2 cases. The shift drum is brand new but I do not know its part number. My question is this: Has the shift drum changed over the various models? Perhaps the one I have is not F2?? If you look at the photo, you can see (pointed out) that the shift drum is not fully home - there is a gap - and this doesn't look correct. This is the reason I suspect the shift drum is the culprit. Your help greatly appreciated!!

[Phil]

Just found the shift drum part-number - the one I have fitted - 24300-392-00

[Old Scrambler]

Not specific to your app............I use K4 cases with a 5th-gear swap to an F2 unit.......as well as the F2 shifter. It shifts as it should.

[Phil]

Thanks - so shift drum remained the same on all Ks + F2s?

[napoleonb]

The only difference I know of in "regular CB's" wasn't in the measurement but in the way the pins were secured.
CR partslist shows a different type of selector but that was done for changing the shifting pattern when used with another reversed gear shifter.

[Old Scrambler]

The shape of the selector pattern has slight variations..........but I would think you would need a 6-position selector drum to match with a 6-speed gear-set.

[bwaller]

It's a 5spd Dennis, difference is close ratio gearsets.

I can't help with the F shift drum, but if you're unable to get an answer, pick up one cheap on Ebay to see for yourself???

[scottly]

The shape of the selector pattern has slight variations...

Yes, there was a service bulletin on this. The two versions were interchangeable though, so either one should work.
On the 750, the lateral location of the drum is set by the neutral switch. Is it fully seated?

[Phil]

It's the neutral selector switch that prevents the selector drum from moving all the way into the machined recess in the inner crankcase. If I remove the neutral switch, it slides all the way home - but then the forks jam on the gears.

[Jerry Rxman Griffin aka MuthaF'er]

Not sure it this applies to you but last time I re-installed the neutral switch it didn't seem to want to "seat" properly and work correctly. I jiggled the external shift mechanism (the external circular part that the shifter dog legs click up and down) inward and outward and everything fell into place.

[scottly]

Was this issue resolved??

[Phil]

Thanks everyone for your advice. I've taken it all apart again - checked everything - and put it pack together again. Shifting through the gears is still a struggle - they most certainly just click in. I'd like to dry connecting a slow drill to the clutch shaft and see if it gets better. If, not, I guess I will paying Nova a visit - it wasn't cheap!

[turboguzzi]

oops, i hope you been turning the shafts by hand as you shift, otherwise gears will never shift....

[maxheadflow]

More important than rotating the gears is that you need to rotate one shaft while holding the other.

[Phil]

Yes, of course, I have been rotating the shaft using the clutch spline whilst changing the gears. I realise this isn't simulating a running engine but it is the best I can do.