Topic: can i fit a 77 supersport carbs on a 76 750ss model?

[stickman]

hi guys, just acquired a 76 750 super sport with carb issues.  it runs but carbs need to be cleaned.  i have a spare set of 77 750 carbs in good shape.  these have a different look with the dome top above each carb.  will these carbs mount up and function as normal on the older 76 750ss?
any guidance will be much appreciated.  for future reference will they also work on a 75 750 k?  the 75 is ok now but you never know. i am 62 yrs. old, new to the group but an old friend to the 750 as i have owned several in the 70's and just now getting reacquainted.  thanks, ed, Lenoir, nc

[scondon]

 Welcome to the forums Ed. The 77-78 carbs have a larger diameter on both the airbox and engine side. They are too large to fit in either the airbox or manifold rubbers of the '76 SS or 75 K. They also have a cable driven choke and the cable end mounts on the triple trees next to the left handle bar mount.

    To use these carbs on your 76 ss you would first need to get manifold rubbers for a 77-78 750K. These will fit both the 76 and under engine manifold and the 77-78 carbs. You would then need to either get an airbox from a 77-78 750F or run pod filters. Finally, in order to mount the new clutch cable you would need the triple trees from a 77-78 750 F or K  or fashion your own cable mount in the handle bar area.

   To use them on the 75 K the same applies though I am not sure which airbox would fit(77-78 F or 77-78 K) if at all.

[TwoTired]

Clutch cable Sean?

Did you reroute your clutch cable through the carbs?  How's that workin' out for ya?

There is also the matter of the "Choke" cable and bar mount the newer carbs need.   

Cheers,

[eurban]

Replacing the triple trees to mount the choke knob is a bit extreme!  It it really isn't all that difficult to make a bracket to mount the choke knob.

[scondon]

Clutch cable Sean?

Did you reroute your clutch cable through the carbs?  How's that workin' out for ya?

There is also the matter of the "Choke" cable and bar mount the newer carbs need.   

Cheers,

    Damn Lloyd, I have a hard day and try to find some solace in the forums and always some joker trying to nitpick the details

[TwoTired]

    Damn Lloyd, I have a hard day and try to find some solace in the forums and always some joker trying to nitpick the details

You'd prefer a different joker? 

[Clyde]

Just to second Scondon's input.
I ran a set of later carbs on my 76-750F, for about a year. The 77/78K use the same engine as the 75/76F engine. (Apart from the engine sprocket-630vs530)
I used 77/78 750K inlet/manifold rubbers but ran pods. I switched back to original carbs in order to use the stock airbox.
Terry-King of Oil Filters- ended up with the carbs.

Regds Clyde

[stickman]

thanks guys for the good feedback.  sounds like i will be better served by having the carbs cleaned on the 76ss.  i will take some pics soon of my 75 750k and post one.  i still think the old 750k with a 4-1 header is the best sound out there on the hiway.  a little prejudiced yes, i admit it.  thanks again for the guidance.  ed

[KB02]

For what it's worth, the Air box on the K8 (78) and F1 (76) appear to be the same... as far as getting rubbers to mount from carbs to air box, the 77/78 rubbers should do the trick.

[eurban]

Perhaps the airbox, but the 77/78 carbs have larger bore fittings on both ends so if the airbox is the same the rubbers that fit into the airbox are either different or more stretched to install (doubtful)  Purchasing a used, halfway decent set of engine side rubbers and a late airbox shouldn't be too difficult on ebay and might cost less than rebuilding the earlier carbs.  This of course assumes that your late set is actually in turn key condition with everything clean (including the pressed in pilots) and adjusted correctly.

[cafe750]

Throttle cables are different too...