Bicycle Tutor

Hello everyone. Im new at this forums and I know something about bicycle fixing.But I have a problem witch I can not solve. My problem is that my Shimano Revoshift wont shift into my last gear.

I have 18 speed system on my bike.It has 6 pack cassette at rear and 3 pack in front. It wont shift to 6th in rear. I already tried to set it with limit screws and setting the cable, but nothing helps. So if anyone have some idea how to fix it plz tell me

Im looking forward to hear from someone and thanks in advance

Limits and the cable tension are the two main things that affect this. Assuming you have these adjustments right, I would check to make sure the derailleur/hanger isn't bent, any inference on the shifter cable, any splits or sharp bends in the cable housing. Does the shifter have enough clicks but the derail won't go into the final position? Or will the shifter not even click into 6th position? Also, please specify if you mean it won't go into the innermost/largest gear or the outermost.

Your cable is probably too loose and the slack has to be taken up before the chain will move up, check this by pulling on the exposed wire anywhere along its length with the rd in top (smallest) gear and the shifter set to the same.

You can set the limit stops, with help, by pushing the rd by hand while the pedals are being rotated with the wheel off the ground and ignoring the shifter.

Now reset the cable ensuring it is taut, use the rd cable adjuster for fine tuning.
Plus the points as made by DaveM.

Hey guys, thanks a lot, I fixed it. The problem was that the shifter was not positioned properly, it was not secured with screw good and it moved to left. Now I secured it into its position and it shifts all speeds again.

Thanks Dave for reminding me that its housing isn't bent, that made me look and I saw a problem.

Also thanks trevgbb, your replay helped me set my shifter to work smooth.

Thanks a lot