synching question

[refeicul]

ok well i was trying to synch up the carbs with the motion pro synch tool. Had the idle set just below 1500 rpm, had the vacuum line plugged and calibrated the tool. got 1,3&4 synched but no matter what i did i could not get 2 to change. so i played with the rest and 2 eventually got went up a bit. but still off by about an inch and a half. It still seems mostly closed but the vacuum dosent seem to be that prominent. so i pulled the air box checked all the boots and how they seat, the filter and reinstalled. same problem! i even tried my back up airbox.

carbs were all dipped new o-rings float height set. I recently replaced the intake boots & o-rings, and the air box boots. as well as sealed the box to insure a good seal and atmosphere. im at a loss the only thing i can think of is an air leak or my tool is screwed up. i checked the calibration 3 times and it was good.


Anyone in or near northern New Jersey?????????

[Steve]

The airbox has nothing to do with carb sync.

You say you plugged the vacuum line. Which end?

You need to be sure the opening to the vacuum port on carb #2 is covered.

Whether you cover it at the carb or leave the hose on there and plug the hose does not matter, but it sounds like that is still breathing.

Oh, and you can NOT get #1 to line up if #2 is not lined up. When you adjust #2, #1 will change, too.

The correct order (according to the factory manual) is to match #2 to #3, set #1 just a bit higher (if you have a crossover in the exhaust), then finally set #4 to match #1.

.

[1948man]

Maybe there is some problem in the linkage so that when you adjust the little screw it is not actually affecting the butterflies.

[Nessism]

Listen to Steve, adjust 2-3 level first, and then come back and adjust 1 & 4 in no particular order after that.

[Steve]

Listen to Steve, ...

Steve is just reciting the manual.

.

[refeicul]

i had the vacuum blocked with the hose on. nitrile glove finger and a spring hose clamp. everytime i adjusted #2 the liquid level wouldent change on that carb, 1,3 & 4 went up or down when i adjusted 2. I dunno ill try plugging the vacuum at the body when i get back to it. thanks again guys!

[Steve]

Could be a massive leak at the intake boot o-ring. Did you change them?


Why not?

.

[refeicul]

yup replaced them last fall. and the boots themselves were nice and soft

[Steve]

Did you do a bench sync to get them close before you put the carbs back on the bike?

If not, it's possible that #2 is just so far open, it's not making any vacuum.

.

[refeicul]

ill take them off and have a look cant hurt.



edit : remembering how the carbs were. the stop screw for 2 was practicaly all the way closed

[Steve]

Easiest way I have found to do a bench sync is to use the idle speed screw to adjust #3 so there is just barely a sliver of light coming past the butterfly. Then follow the proper sequence for the others.

Here is what you should be looking for, note the approximately equal slivers of light at the bottom of the butterflies:



When you are done, you should be able to use the master idle speed screw to see that they all open and close at about the same time.

The easiest place to see them is right as they open or close. Beyond that, it's hard to tell that one might be .025" open and the next one is .028", but it's easy to see when one is at .001" and the other is at .004".

.

[refeicul]

funny this is Steve, when you posted that is just when i finished doing just that. #2 opening was like those pictures about the thickness of the smallest of my feeler gauges. the rest were a bit less barely any light coming threw. so i adjusted them accordingly. not going to fire it up till tomorrow neighbors don't care to hear a bike fire up this late.

a little birdy told me about that trick there....... i wonder who

[Steve]

Hopefully that will do the trick.

Now you will be able to join the ranks that preach "BENCH SYNC".

.

[ddaniels]

I use the paperclip method to bench sync. Just gotta be careful not to scratch the bores.

[refeicul]

well i posted before that the bike ran ok but would bog when i tried to dump the throttle for some head kicking goodness and epic fail. when i got them close earlier i gave it another shot and WOW . defiantly will spread the joy.. the other tip i could think of is dont half ass stuff or take short cuts!