Topic: first post!! 78cb750 parts help

[bhorocks]

Hey founds this forum the other day and lots of great projects goin on here!! 

  I have always wanted a cb750 and got lucky the other day and picked up a non running 78 for $350  all parts are there and looks great!
I'll upload some pics later today as i have not taken any yet! 

  Got it runing today after tearing the carbs down and cleaning the snot out of them but the bowels are leaking and nobody in town sotcks floats or needles...  My floats are all craked up and need replaced.

anyone able to point me in the right direction to find theses parts?

this is actually my third cb my first was a 72' 125 and my second a 69 i think 350 whcih got stolen.....

but now i have the 750!

thanks

[bhorocks]

ok got the float on one working and the other almost. but i still woould like to replace as they are all cracked...

also it hesitates when i go to give it throttle unless i baby it in the lower rpms.  i have the mixture adjusting out 2.5 turns like the book says anyone ideas which way to turn for better low end throttle control?


other than that it runs great but the honda 4to1 pipe makes it hard to use the rear brake..

[TwoTired]

Your bike has an accelerator pump to squirt fuel into the carbs when he throttle is opened.  Engine pickup is much better when this works.  Look at the bottom of #2 carb.  There are also two check valves that must function for that pump.  And, the squirt nozzles in each carb must be clear.

It look like someone has grafted a 75 or 76 F model exhaust onto your bike where there was a 4 into 4 before.  The extra bulk of the pipes is what is blocking you brake pedal.
You might look into getting an F model brake lever.  Or, get some after-market pipes that are designed to clear the original brake lever.

Cheers,

[bhorocks]

cool im going to go pul that now and clean it....

yeah aftermarket pipes are a must.....
drop bars, seat, etc...

[shoemanII]

now that's a nice find for $350.  good chrome, side covers are still there and it runs.  life is good.
bobp

[Johnie]

Welcome to the board...WOW...$350 for a 750 in nice shape that actually runs.  You did well.  Treat her good and she will treat you good too.  You have a real vintage collectable there.  These bikes are pretty much indestructable if they had at least fair maintenance over the years and it looks like yours has.  We like to hear of members progress so post more pics and keep us informed...
 

[Loudpipe]

You may possibly be able to find rebuild kits through your local honda dealership, but a more likely bet is off of Ebay.  There are several stores which offer kits for all years and models 750.  As for the bogging down in the lower rev ranges, you need to pull the plugs and make sure they are a nice, cardboard brown color.  Lower rev sluggishness can be attributed to the engine running too rich (black plugs).  It can also be attributed to the timing being off, and the number one rule of engines is to make sure the electrical system is in order before you going #$%*ing with the carburetors, so check that first.

[Kevin D]

Heres a good place to look for parts:

http://forums.sohc4.net/index.php?topic=743.0


Myself, I got a few carb things from sirius. I don't know if they have floats. I recall getting a float from the dealer. Expensive, but available.

[Johnie]

Try to strike up a good relationship with your dealer.  There are a lot of parts still available from your Honda dealer.  My dealer gives me a 15% discount on everything as he really likes the fact I am restoring the history of these bikes.  I can get parts from my dealer cheaper than I can at Honda Direct Line.  For those hard to find parts I have used Yamiya from Japan.  There is also www.cmsnl.com and David Silver Spares.  Have fun with your new toy...

[jtb]

email them at motorcyclecarbs.com and ask about floats.  Don't know if he can help or not, but it's worth a shot.  Someone has a set of 77 or 78 cb750f carbs on ebay right now, those floats should work.

[eurban]

I have opened up a good number 77 / 78 style carb racks and I have yet to see a set with age damaged floats.  You could likely locate a used set of carbs on Ebay (like the rack the previous poster mentioned) that would give you a set of useable floats and numerous other spare parts as well.  You could also see if someone here has extras. . . .If you can find the floats new reasonably cheap than by all means go that route, but I personally wouldn't be worried about using a used set of floats as long as they check out OK as most have in my experience.

[bhorocks]

yeah the dealer wanted 40 each. i was like no way....

they seem to be working they were jsut all cracked up. guess ill go look  at all the electric now before trying to tune anyhing in the carb.

thanks for all the input everyone.

[jtb]

Hey, Bhorocks, I think I might have some floats.  I'll check and let you know.
John

[jtb]

I do have a set.

[uptworedline]

cool im going to go pul that now and clean it....

yeah aftermarket pipes are a must.....
drop bars, seat, etc...

you should let me know if you sell your seat, i am looking for a cheap alternative to a $$ eBay seat.
<<< cause look at the one i'm stuck with

[Hush]

Just a note of caution, I had a blonde moment when putting my floats back in my CB650PZ and in poor light and keen to get the old girl started I put all 4 sets in upside down.
"Waits for laughter to abate"!
Apparently carbs need more than a drop of gas to feed the engine so had to remove and redo all floats.
This made me see the logic in replacing all those fiddley little cross head screws that hold bowl on with hex/allen key studa!

[bhorocks]

I do have a set.

how much would you be wanting for those??  I could sure use a good set.

thanks for looking!