750 Starter Clutch Timing Marks PM / A.

hooksey

hooksey

Hero member
Location
Vic , Australia
Fellas ,

Can someone roll a tape round from PM mark to the Advance mark and let me know the measurement in mm ?

I have two 750,s here with two different measurements  :-\

Obviously would like to get it set right as i imagine 6mm diff between marks would move full advance by quiet a few degrees  :o

Ta , Hooksey
 
Hi, Hooksey.
As I don't have a tape, take the whole perimeter.
And calculate 40? out of 360? (which you'll have to do yourself)...
I think this subject has been covered before>

hth
Ernesto
 
Thanks Ernesto and Tippie , thats the measurement i was looking for, as one of mine measures up at 42mm between the marks.  :o To much Advance using these marks !!

Does anybody know if the sfc had  factory marks set up differently than stock sf.
 
I've run across a few where the markings were incorrect. Even had one with no markings at all. If possible do take the time and check everything by using a degree wheel and remark if neccessary. Trust but verify...

Tom
 
Hello Hooksey,
Toms advice is very good. To be sure about crank/piston positions you need check & verify where they are. Can I suggest you get yourself (beg borrow or steal) a decent tool to verify TDC.
All the best
Rocket
 
Rocket said:
Hello Hooksey,  Can I suggest you get yourself (beg borrow or steal) a decent tool to verify TDC.
All the best
Rocket
Click to expand...
Too true Rocket , you obviously know a fella who has one such tool  8) confirmed my staw method  (now confined to Milkshakes  :P ) wasnt two far out, just needed to confirm factory markings as i now have two different  Full Advance measurements on two different sacshe boxes set on the same curve  :-\

See ya Sundee 
 
I gather these "Full Advance" measurements where achieved with a degree wheel and timing (strobe) light?
And I seem to recall that while you have the same electronic boxes in the twins, you have an optical pick up in one and a Hall Effect in the other?
We may need to consult LL for some enlightenment and the Mirboo Brewery might provide just the right venue to solve this mystery. :D
 
Rocket said:
I gather these "Full Advance" measurements where achieved with a degree wheel and timing (strobe) light?
And I seem to recall that while you have the same electronic boxes in the twins, you have an optical pick up in one and a Hall Effect in the other?
We may need to consult LL for some enlightenment and the Mirboo Brewery might provide just the right venue to solve this mystery. :D
Click to expand...

Points.
Paul
 
Paul Marx said:
Points.
Paul
Click to expand...

Ah Paul,
I too am a huge fan of ambiguity and innuendo, but FFS!
Once-upon-a-time in good ol' redneck Queensland a lady who ran a fish & chip shop was elected to State parliament. Pauline Hanson was her name.
Her great contribution to the nation was coining the phrase "please explain"!
 
750s did not have electronic ignition, only points.
Only 750 with electronic ignition was the 750SFC Elettronica.
 
OK, done some calculations , (with the help of me mate).

TDC confirmed starting point.
Circumference of free wheel 321mm.
PM / A,  Factory marks confirmed at 37.5/38mm apart.
Gives you Full Advance of 42.8 degrees  :o

Full Advance mark set at 36mm from PM
Gives you Advance of 40.4 degrees  8)

Tippie/Ernesto sound bout right to you ?

But hey i am a plumber, probably tipped over to many tins of blu goo  :D





 
All well and good if the unit fits tightly onto the crank. Most do but I've had enough of them come through over the years with worn woodruff keys or buggered slots on the starter clutch itself from assorted butchery allowing these things some movement before they are snugged down onto the crank. Yes, it's a pain in the butt if you don't have the tools handy but it is definitely worth taking the time to do correctly. Simple peace of mind knowing it's OK for one. Should you have any sort of ignition problems you have a solid base to work with knowing the timing marks are spot on. One less variable to deal with.

Tom
 
Grant said:
750s did not have electronic ignition, only points.
Only 750 with electronic ignition was the 750SFC Elettronica.
Click to expand...
True however a lot of people have now replaced the points with electronic systems.
Regardless it is best practice to check full advance with a strobe so the full advance mark, or your chosen full advance in my case, is important.
I always clamp a wire to point at the marks, set up from TDC by whatever of the various means. The mark on the case of as SF is too far away from the starter clutch boss, too vague (for such a precision instrument as an SF!!!).
 
This is the comment I was replying to:

"And I seem to recall that while you have the same electronic boxes in the twins, you have an optical pick up in one and a Hall Effect in the other?"

 
Grant said:
This is the comment I was replying to:

"And I seem to recall that while you have the same electronic boxes in the twins, you have an optical pick up in one and a Hall Effect in the other?"
Click to expand...


Ditto.
Paul
 
Arrghh bugger  :'(  ya mozzed me Tom ..... fitted up Ignetech box with local guru Lex tday  :
Bikes runnin just fine n dandy  :) .

In the process have found the starter clutch is spinning on the crank  :'( :'(
So the question is whats the best fix for this Tom ? and can it be done, motor insitu.

Hooksey.
 
hooksey said:
Arrghh bugger  :'(  ya mozzed me Tom ..... fitted up Ignetech box with local guru Lex tday  :
Bikes runnin just fine n dandy  :) .

In the process have found the starter clutch is spinning on the crank  :'( :'(
So the question is whats the best fix for this Tom ? and can it be done, motor insitu.

Hooksey.
Click to expand...

All depends on how buggered the slot and freewheel taper are...

piet
 
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