Topic: bench synch ?

[smpls70]

Was doing a bench synch on a set of 72' 750 carbs last night , went with the flash light method , and got em' pretty dang close to lookin even across the whole rack, but, according to the SALOCAL web site , they want " no more then a couple threads above the lock nuts, NO MORE!" is this absolutely impaerative ? if so, why ? I keep coming up with a few more threads on one side then the other and its driving me nuts , or am I just over thinkin' this ??

[CycleRanger]

The manual says the same thing.

I imagine that if there's too many threads above the nut the slides and needles might not be able to close fully.

btw, what carbs do you have?  Are they 7A or 657A's?

[smpls70]

The manual says the same thing.

I imagine that if there's too many threads above the nut the slides and needles might not be able to close fully.

btw, what carbs do you have?  Are they 7A or 657A's?

Thanks cycleranger, I have the 657A, where did you get that page ?  It is not in my manual, I have the downloaded Honda one, must be missing ,guess i'll  have to give it another try, clip is in the 3rd notch down , if that makes a difference.

[CycleRanger]

Full CB750 shop manual in PDF available here: http://www.honda4fun.com/man_officina/man_officina.html

Here's the part that has the info about K1-4 carbs where I got that image.

http://www.hondacbfour.com/download/man_officina/pdf_manuali/CB750_K-F/CB750_5.pdf

[smpls70]

Very nice, thanks bud !!

[CycleRanger]

You're welcome.  I'm rebuilding my carbs for my 750K5 now.   I've discovered the PO mangled the stay plate pretty badly. 
Unfortunately Honda, in their infinite wisdom, pinned the pivot rod on the later versions so it makes dissasembly problematic....
 

[smpls70]

Keep comin up with pretty much the same results, #1 - 2 threads, #2 - 2 threads , #3 - almost 3 threads , #4 -3.5 threads,.thinkin im just gonna put em and see what happens, im just overthinkin this waaayyyy to much 

[srook]

The arm that lifts slides 3 and 4 may be cocked lower than the arm that lifts 1 and 2.  Their is really nothing you can do here as the arm is located by a bolt and a flat on the rod it runs on.  Sorry if this sounds strange but when you look at the carbs with the tank off you will see what I mean.  Try to adjust the location of the arms by loosening the lock nut and looseneing and tightening the locating bolt on both arms.
Scott

[CycleRanger]

And be careful not to over-tighten the slow jet so it breaks off and you spend 10 minutes looking for a drill bit so you can drill it out, being thankful it's soft brass, and then jam a tiny screwdriver into it to back out the broken part...
Not that this has happened to me or anything...

[smpls70]

Srook; I think you may be on to something, makes sense . the carbs are on so........ next time i'll look into that, cause im sure they are coming off sooner then later.
 CycleRanger that sounds like something I would do as well , as I said the carbs are back on and still have a high idle, was able to calm it down around 2000 grand and it fluctuates, but is a little better , , think im in need of a carb synch tool , whats one cost, do I want to stay away from a cheap one ? or does it really not matter ? Ill have to do a lil research.