Topic: Intake manifold spigot broken...help.

[JWExperience]

I have a 78 cb750f and one of my intake manifolds that connect the rubber boots to the head is broke. I can't find the exact name or part number for it or if it's even still available. Does anyone have any info on where to find one or how to fix it? I purchased this bike with two motors, it has a running k7 in it now but I want to rebuild the original motor with the broken spigot so the bike can be original again. The f motor also had some teeth sheared off in the tranny which is why I tore it down in the first place. Thanks in advance for any help with this.
Jay

[kmb69]

Jay,
Those spigots were never available as a replacement part. It is also tricky to remove one intact since they are glued in at the factory with heat resistant glue. Cheapest fix is usually to find a good used head. There are posts somewhere on this forum about removing the spigots. Also, the F1-F2 spigots are a couple of mm's larger than the K's so you have to find a trashed F1-F2 head for a replacement. You could also machine a replacement fairly easily if you can get the old one out and the threads in the head remain intact.
Keith

[70CB750]

I seem to remember that heating head in the oven was part of removing spigots from the head.

[KRONUS0100]

i did 2 of mine on the gas grill.....................heated grill to 400 and put the head on it for 15 minutes with the lid up.  use welders gloves to touch head
place it on 2x6 adnd use proper size socket and 1/2 or larger ratchet to spin it out.  have to be quick as the head cools rapidly enough for the glue to harden back up.  reheat head and spin new spigot in.
the f model has larger intake spigot than the k models.   i think i might still have an extra f model spigot

[kmb69]

My previous posting.

http://forums.sohc4.net/index.php?topic=115072.msg1296766#msg1296766

However, it sounds like Jay may not have the hex left to put a socket on.
Got to be real careful removing spigot threads so as to not damage the head.

[KRONUS0100]

just came in from barn.  if i had an extra, it aint out there now.  sorry.

[Don R]

I'd look for a head. If you have the broken part welding could be an option. A few guys remove the F2 head rather than replace the valve guides, maybe someone has one laying around. I auctually have one, but I'm not sure if I want to part out that motor.

[JWExperience]

I did find one thread that talked about the spigot but it seemed to kinda breeze over it a bit. I got it from the PO as is and it no longer has the hex. When I bought it I saw that part and figured it wouldn't be a big deal, man was I wrong! If anyone has a spigot that will fit my f3 let me know please.  Thanks for all the replies.

[JWExperience]

Kron, u can disregard the pm I sent, I got all excited when u said u might have one and didn't read further! 

[Jerry Rxman Griffin aka MuthaF'er]

You probably won't find a loose one. Either a replacement head or a trashed head for donor spigots. Should be plenty of scrap F7/F8 heads laying around.

At this point do you know the condition of your head? They have the propensity to eat guides and end up needing an overhaul. You may be getting yourself into a bunch of #$%* but that's how these old bikes go. 

[Pat_at_APE]

There are actually two different thread pitches (at least) so just finding a replacement spigot doesn't mean it will fit. 

Send a close up image of your removed spigot to jeff@aperaceparts.com

We have one style here and maybe it will fit your head.  I think an image of it would allow him to see if what we've got will work for you. 

Good luck! 

Pat at APE

[JWExperience]

Sounds good Pat, I'll look into getting it out. As far as the condition, it came out of a bike with 6800 miles but one of the intake valves is nicked up on top where the tappet makes contact. I was thinking of seeing if I could ship it out to Mike Reick to see if he could rebuild it with new guides and retainers. I believe the guides and retainers are the weakness for this head.
Pat, is this something u guys could quote me on?

Ultimately I would love to find someone that would rebuild this head with some upgrades and take my spare parts off my hands in trade. I have that running k7 motor and a extra tank and round carbs.