help carb sync nightmare

[icekillah]

I have synced carbs before but after today i have no idea what to do

I used a mercury manometer from motion pro
I blocked off the vaccum line
used the idle screw to increase the idle
at first the mercury was not moving at all(stayed at the bottom of the manometer) then I moved the middle screw and the left side(carbs 1&2) went way up to the top of the manometer but when i would check the exhaust pipes(on 1&2 number 2 would be luke warm at best) they would be cool and pipes(3&4) were extremely hot could this be due to a bad plug in #1? any how when it would run it took alot of time for the throttle to respond and would take alot of time for the engine rpms to return to idle (cyber poet said i might have a vaccum leak in a previous post) is there something wrong with my bike?

[The CyberPoet]

Well, you might still have the vacuum leak. Did you have your air filter on while you were doing the balancing? It should be on, and the engine should be warm (stick on the manometer, then let it idle for 3-8 minutes [depending on how cold it is where you are] to heat it up, then balance).

This is the way it should work:
Connect one hose to each carb.
Idle to warm.
Turn up the idle setscrew to 1800 RPMs. If the mercury doesn't rise in *any* tube, raise the idle further until the mercury rises to about the middle of any tube.
Once the mercury rises (it'll bounce normally), adjust that pair until the mercury readings balance between that carb and the other carb of the pair (i.e. - 1&2 or 3&4). If the mercury drops again without the other one coming up, raise the idle again. If you get to 2300 RPM with the mercury coming up, you definitely have a vacuum leak.
Repeat on the other pair.
Then balance the two pairs against each other using the screw in the middle of the stack (this should be the last step).

Good Luck!
=-= The CyberPoet

[Anonymous]

Is your air/fuel mixture consistent through the 4 carbs?

[md86]

Is your air/fuel mixture consistent through the 4 carbs?

That wouldn't matter . As the piston goes down , it creates vacuume , which is what sucks the mercury through the tubes . If the piston is moving , so too should the mercury . Unless there's a vacuume leak ....

[icekillah]

the airbox was off in carb #4 is that why pair 3&4 were really hot compared to 1&2? also should the vaccum line on the carbs be blocked off? just built a homemade auxilary tank out of pvc tubing looks promising i'll make a guide on how to do it if anyone is intrested

[The CyberPoet]

No filtration = carbs running lean.
If you had pods or some other solution that only filters for some of the carbs, that would explain the hot vs. cool.
Put the airbox on (or pods or whatever you use for filtering) and try it again.

Cheers,
=-= The CyberPoet

[trinc]

also....

there is no airflow to keep the engine temp in check, make sure you put a fan on it while it's sitting there idling.

tim

[icekillah]

just tried resyncing again and the vaccum nipple was busted on carb #4 i think that had to be it

[noodlemice]

$80 to get it digitally sync'd by a mech. Best $80 Ive spent.

[Special K]

GOOD MECHANICS TIP:

Spray brake cleaner around the intake boots, carb tops, etc. while engine is running.

If engine bogs down or races, you have just found a leak!

Cheap, quick, sure fire. 8)

[The CyberPoet]

$80 to get it digitally sync'd by a mech. Best $80 Ive spent.

I'd infiintely rather spend the $100 for the best solid-slug sync on the market and not have to pay another $80 next time I adjust my valves or work on my carbs. One-time purchase.

PS - the digital sync's really aren't special (other than pricing), except they make the sync procedure so simple a horse could be taught how to do it. It doesn't give you any advantage in how accurate the actual sync is, or how long it takes if you know what you're doing.

Cheers,
=-= The CyberPoet

[icekillah]

ok i just took another go at doing a sync and while attaching the manometer to the vaccum ports on the carborators carb #4's vaccum port was cracked off maybe that was the problem maybe it was not but any how seems its going to take a week or so before my new carb bank comes in

[The CyberPoet]

That could very well be the problem. Did Special$K$ set you up with a replacement carb body?

Cheers,
=-= The CyberPoet

[icekillah]

actually i ended up buying a broken carb bank off of ebay, nice to have one around for parts instead of paying 20 bucks for a new o-ring off of bike bandit