On my 1975 CB750K the tach does not seem to want to go over 5K. At about 4 and a half the needle starts to fall back. I replaced the cable but no change. Are these units repairable? At idle and to about 4 seems to work o.k. but I suspect the needle response is a little behind what the engine is actually doing once it gets over about 3K. 3K and under seems to work fine. Can it be fixed? What's involved?
I hope someone out there is familiar with this.
Thank you (great board by the way, you folks are awesome!!

)
JK