78 CB750 First bike build

[Sheff]

Hoko wrote

Paint still looks good, thats a good looking bike.  Vacuum leak will only be between your carburetor and the cylinder on the intake side, you dont have to mess with your exhaust headers at all.  If you have a carburetor leak, you are going to have to pull your carburetor assembly off the bike and set the float level.  Look under Repair Sources on the forum main page for the Carburetor cleaning tutorial.  It will show you how to set your float levels.  I would check all your float levels while you have it off. Check all your float needles and jets, inspect and clean each needle seat (jet).  A poor sealing float jet will overflow the bowl just like incorrect float levels.  Each one should be smooth and clean.  You can clean them with a Qtip and chrome polish. I would also visually check all your jets, Pilot Screw jets, Slow Jets, and Main Jets and by blowing carb cleaner with a spray can of carb cleaner with the small tube or compressed air through them to see if any of them are clogged.  I used a metal high E guitar string to ream mine out, I also soaked them for 2 weeks in chem dip because the PO left the bike sitting on his driveway for 5 years so all the jets were choked with varnish but if yours doesnt have varnish thats not necessary.  Be careful not to lose the tiny o-ring on the #2 carb.  Also when you pull your Pilot Screws out be careful not to lose the tiny flat washer on the end of each one.  I lost 3 of them before I knew they were there.  Couldnt find a washer that small anywhere and had to order 3 entire screw,spring and washer assemblys at $13 bucks each. There is also a tiny o-ring on the end of each pilot screw that usually stays in the bottom of the hole which you will have to pull out with an o-ring pick.  Replace the o-rings if they look bad.  Auto part stores have them.

thanks man yea my friend who I bought it off of pretty much kept it in the garage and other than some surface rust and some missing pieces the bike is in pretty good shape. if I'm gonna pull these carbs again though I wanna get the carb kits but all the ones i look at don't seem to be the right ones and i cant get a straight 78 carb kit. any ideas where I should look checked my local bike shop and they couldn't find one?

[Hoko]

You can get the gasket set here http://www.servicehondapsn.com/fiche_section_detail.asp?section=2036995&category=Motorcycles&make=HONDA&year=1978&fveh=123330
The float needles don't come with these kits, you can get them from vintagecb750.com  
If they are metal tip needles and look ok you can reuse them.  If they are rubber tip, replace them.
Something to remember is before pulling the pilot screws, turn them in till they stop (not tight) and count the revolutions and write it down so you can set it the same when you put it back together, although being into it this far you may have to set it at default factory level which is 1 3/4 turns out and re-sync the carbs.

[Sheff]

now the 77 750k and the 78 750k have the same carbs don't they???
because if so I'm going to get the 77's carb rebuild kit and rip this puppy back out.

[Sheff]

wait is mine and F or a K?!?

[Piute]

                                             
                                            My "77" F2 came with Key-top carbs,


                               Very simple just take your time,follow all the info

[Hoko]

78 Super Sports are F

[Sheff]

Hoko wrote

78 Super Sports are F

well damn i've been telling everyone wrong....