Topic: RE: cb750 Broke a plug gotta pull the engine

[chewbacca5000]

O man what a bummer. I was at the home stretch with my 750 cb750 restro mod and I broke a plug, and now I got to pull the engine.

It was a good runner until now.  Looking for some options here.  What would you guys do?

[flybox1]

bummer! where did it break? picture?

[chewbacca5000]

bummer! where did it break? picture?

It broke completely off in number 2.  It is always the freaking inside cylinders where you can't get at it.  Will have to remove head to get that plug out.

Thinking of possible upgrade to cheap 836 kit.

[dusterdude]

True dat,i stripped my head on number 2 but was able to run a thread chaser and straighten it out

[Vinhead1957]

Big easy out . You break the porcelain out to get to metal. Cylinder at TDC and vacuum out the porcelain chips

[chewbacca5000]

You have to pull the head because the outside nut is no longer reachable with the wrench? Or is it an access problem to the port while the motor is in the frame?

1/2 the spark plug is broken off in the head.  I guess my plan is to pull the motor and get the other 1/2 of the spark plug thread out.  Should have just left it alone.  It was moving or so I though.  Broke the whole thing and most of the electrode.

Trying to figure how long it will take to install a 76F head and jugs vs getting the broken plug out.  The F is 836 bored and ready.  If I remember correctly removing the old base gasket is most of the time in a top end?  Scrap, scrap, scrap....

[Stev-o]

Sorry to hear........ How 'bout putting a Franks weldless frame kit on it so you can pull the head?

[chewbacca5000]

Big easy out . You break the porcelain out to get to metal. Cylinder at TDC and vacuum out the porcelain chips

^^^ This is what I've done in the past

[chewbacca5000]

Sorry to hear........ How 'bout putting a Franks weldless frame kit on it so you can pull the head?

Not too crazy about cutting the frame since it is powdercoated, but it is a restro-mod so this might make some good sense to do.