CB750k intake valve problem

[dixiedevil]

Bike: 1978 CB750K

On my number 4 i started blowing gas and losing power. I tested my compression, and got nothing. Pull the intake valve cover off to find that the nut has spun off of the tappet adjusting screw. It some where in the head!!!. The problem I am facing here is retrieving the nut and also the Rocker arm is dead mashed into the Valve cotter & valve spring retainer not allowing me to gap it like I should, and YES its at TDC as i can gap #1. What do i do here? I am on a very very limited budget so I need to fix it at minimal expense. I am afraid that the spring has become unseated and this is why it is doing this.

I have attached a picture of the said parts.

HELP!

-Dixie

 

[hillsy]

The only way the valve spring can unseat is by the collets dislodging - which would drop the valve into the cylinder. You would know about that

Have you taken the entire cam cover off? You will need to do this to find the missing nut and investigate further. No quick fix for this problem without pulling out the spanners.....

 

[dixiedevil]

I don't really know what I'm doing. DO i have to remove the motor from the frame to take the cover off? and by spanners?

 

[Deviant1]

I'm not sure for your year model, but mine's a 72 and the motor has to be pulled to remove the valve cover. Sucks. SOHC4 forum has a guy over there making frame kits to make the braces that prevent the cover coming off removable. I almost went this route, but I didn't like the idea of cutting the braces off of my frame and replacing them. Something about it threw up a warning flag in my head.

 

[crazypj]

Unless you cut out the lower top tubes from frame you will have to remove engine.
Its quite heavy, about 212lbs.
Make sure clutch cable and starter cable are disconnected before you lift it out :
Takes about 2~3 hrs

PJ

 

[dixiedevil]

Unless you cut out the lower top tubes from frame you will have to remove engine.
Its quite heavy, about 212lbs.
Make sure clutch cable and starter cable are disconnected before you lift it out :
Takes about 2~3 hrs

PJ

Got this sucker out in about 30 mins! Ok so now what!

 

[hillsy]

Take the rocker cover off and have a look

 

[crazypj]

Got this sucker out in about 30 mins! Ok so now what!

Total time for cover change, getting it back in and running takes a bit longer
as hillsy said, get rocker cover off, then take a look inside, you haven't disturbed anything yet, the cam runs on seperate towers under cover

PJ

 

[Wee Todd]

SPANNER TIME!!!!!!,,,sip your java,,,read your manual(on the shitter, good place!),,break out the metric goodies,,go back and read it again...and again ,you need a new (used )rocker,examine the top of your valve for damage,as for your locking nut,flip the engine upside down,,,start shaking, if it doesn't appear, it very well may rest in the bottom of the crankcase or chew up something,,,fish with a small magnet.......good luck

 

[dixiedevil]

I got the cover off today to find that not only one nut had come off but the nuts on intak 2 & 3 had also come off. Thankfully the had not travelled to far. Hypothesis and pictures coming soon. There is something definitley funky about #4 intake components

 

[gane]

I got the cover off today to find that not only one nut had come off but the nuts on intak 2 & 3 had also come off. Thankfully the had not travelled to far. Hypothesis and pictures coming soon. There is something definitley funky about #4 intake components

 

[Rocan]

you got lucky nothing else went wrong!

id check everything out and make sure its all to spec before putting the motor back in.... might as well seeing as how you have the motor out already

 

[dixiedevil]

*EDIT*

so i fgianlyl figured out what the problem is here. The valve cam out of the clip but has not fallen into the motor. so im assuming the valve guide is bad and/or the valve is bent.