Topic: CB750F Rocker frozen? HELP

[zeus87]

Picked up a 1975 CB750F from a friend.  He recently replaced the cam chain.  Anyway, i am trying to adjust the valves, but noticed that while trying to set exhaust valve on cylinder #1 the rocker is locked up against the valve itself, leaving to room to get a gauge in.  I took the adjustment screw right out, ad can see that the valve is hitting up directly against the rocker.  What is going on here?  HELP! thanks!

[MCRider]

We just had a thread on this elsewhere. But  Most likely where you are set you should be on cyl 4. If you are set on T for 1-4, then its one or the other but not both. You turn the crank 360 to do the other one.

[zeus87]

hmm.  If the rocker is frozen against the valve without even having the adjustment screw in, shouldn't this be a problem no matter what is at TDC?  i'm asking, as i really am new to this.  Thanks -justin

[MCRider]

hmm.  If the rocker is frozen against the valve without even having the adjustment screw in, shouldn't this be a problem no matter what is at TDC?  i'm asking, as i really am new to this.  Thanks -justin

No it would be expected, that the rockers sans adjusters would still be forced by the cam lobe into the top of the spring stack. Only the valves that are on the base circle of the cam would be free from this situation.  

So I can tell you, FYI, if you have the crank set at T1-4 there will be 4 rockers that are pushing on the spring stack, with or without the adjusters in place, and with a great deal of force, and 4 that are on the base circle where you could remove the adjuster easily, with no spring pressure.

Either cyl 1 or cyl 4 will be free of spring pressure and ready to set. THe opposite one will have spring pressure against the rockers, with or without the adjusters in.

But don't let me confuse you with stuff you don't need to know. Set on T1-4, determine which cyl is ready to set (1 or 4) by grabbing the top of the adjusters and seeing if it clicks and is free of spring pressure. Set them, turn 360 deg and set the other cyl.

Same for T2-3.