Bike won't shift into taller gear at high RPM

Hello,

When I shift my 750 from 2nd to 3rd, or 3rd to 4th gear at a very high RPM, it will either not move into the next gear or it will not be engaged in either gear. To try and describe this clearly, at a very high RPM I will pull the clutch lever in, shift into the next taller gear fast, not "feel" any gear engagement through the shift lever into my foot, then after I release the clutch lever the bike will either be between gears (twist the grip and nothin goin to the wheel) or it will still be in the same gear. Once the RPM drops a bit I can shift the bike directly/smoothly into the next gear. Does anyone have a suspicion as to why this is happening? This is the first Norton I have had so far and it has always done this. Are we supposed to let the revs drop considerably before we shift in general?

I searched this forum and couldn't find a thread about this so please direct me to one if there is one that exists. Thanks very much for any assistance with the matter.

Primary chain adjustment that is too tight can cause various shifting issues or expose worn gearbox internals (bearings).

I like to keep pressure on the gear pedal until I've let the clutch lever out. Sometimes the last bit of engagement happens as the drive is taken up.

Don't just dab at the pedal.

Triton Thrasher said:

I like to keep pressure on the gear pedal until I've let the clutch lever out. Sometimes the last bit of engagement happens as the drive is taken up.

Don't just dab at the pedal.

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This

Thanks for your thoughts. I'll take a shot at keeping pressure on the gear pedal as I release the clutch lever.

Mine tends to do this when I have ignored the fact that my clutch plates are starting to stick together.

rvich said:

Mine tends to do this when I have ignored the fact that my clutch plates are starting to stick together.

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I had that in the back of my mind. Not too long ago I sand blasted the plates and changed the oil but that didn't solve the problem. New clutch plates maybe? How about putting more tension on the clutch cable?

What kind of clutch plates are you running? I assume you sandblasted the steel (drive plate)? Did you happen to check to see if they are warped? I have fiber plates and use 3M Brake Cleaner on them if they feel sticky. Make sure the clutch is adjusted so that there is some end float on the push rod and then take slack out of the cable at the handle adjuster. It's possible it isn't disengaging fully enough to take tension off the gears at high RPM. Or it could be some of the other things mentioned here or a combination of all of them.

Russ

You should not need to use the clutch lever when changing up through the gears, simply easing the throttle should be enough to unload the gears. With the standard box, coming down through the gears needs the clutch lever to be operated and a heap of revs to be used to match the gears so the change is smooth. The comment about the primary chain being too tight might be correct. You seem to have an internal problem with that gearbox. I tried road-racing with the standard gearbox, it was impossible. I could not do anything smoothly. But that is not your problem, for normal road use the standard box is good enough.

I would check the tension of the primary chain first, looking for tight spots. To much axial play of (one of) the gearbox shafts might produce this behavior too. With the standard gearbox the ratios are rather wide so I would recommend using the clutch if not on the track. Awkward clutchless shifts either way could ruin a gearbox quickly.