Monometer readings?

[lighter223]

Obviously you guys have synched your carbs... So what is the normal vaccuum reading on the monometer...?


I am gettting between 18 to 20  thouh I am in the middle of the procedure right now...

So let me know what all you guys got

Thanks,
Anthony

[txbanditrydr]

I haven't a clue as to what "normal" is...  All I look for is that they're even across the carb bank - this is using a 4 tube set-up.

[lighter223]

Ok first off  I forgot to mention the fact that all cylinders are firing.  the number one cylinder needed 1/2 turn out more to fire.

I do have a 4 tube setup...  but unlike the suzuki carb tool I have mercury instead of steel balls and numbers instead of a "center or level".

I have gotten them close to "level across the board" as I can using the A/F screw.  I read in the manual that you have to adjust the screws on the linkage connecting all the carbs and not the A/F screws.  This would adjust each carb differently though so how exactly does it work  OR why does it work... Can anyone explain why synching works ( if you need more clarification of the question just ask... cant really think of any other way of saying it right now)

Thanks,
Anthony

[txbanditrydr]

Go back and reset the A/F screws to equal number of turns.... those are NOT used to sync the carbs.

There are 3 adjustment screws between the carbs... they are used for balancing them out.

First.... use the screw between carbs 1 & 2 to balance 1 & 2
Second.... use the screw between carbs 3 & 4 to balance 3 & 4
Lastly... use the screw between carbs 2 & 3 to balance the 1/2 and 3/4 set

Be very gentle - use as little pressure on the screws as possible... just pressing too hard with the screwdriver will alter the balance.  Use small turns... follow the 1,2,3 steps and repeat until you get all 4 mercury columns the same height - regardless of how high.

Don't forget to plug any vacuum hoses left undone (ie: petcock vacuum line)

If you take more than 10 minutes it's advisable you put a fan in front of the engine to provide proper cooling.  On the other hand... the engine needs to be warmed up and the revs set at 1,700 rpm for the adjustment.  Some folks use the idle adjust screw to get the rpms up - I prefer a throttle lock.  For grins... repeat the whole procedure at idle speed (1,200 - 1,300 rpm).

Good luck...

[lighter223]

So how do you do each one individually?  Dont the screws do both at the same time? 1&2 being adjusted at the same time what if 1 and 2's reading are different but rise and fall at the same time? for example:

say that cyl 1 is level at the center of the monometer and 2 is 1/4 lower  wouldn't turning the screw adjust both simultaneously? so that I would end up with cyl 1 at level+1/4 and cyl 2 at level?

[mademiriam]

there is (or SHOULD be) a adjust screw between every carb. To adjust between 1 & 2 turn the one between those two, then just as mentioned proceed to 3&4 and only when those two 'pairs' are balanced you will balance with the middle adjust screw to get everything even. When you're using the middle screw yes you are in fact balancing all four carbs at the same time, but since you evened out 1&2 and 3&4 it doesn't matter if you move two at the same time.
Hmm its a lot harder to explain than it seems to do.

[txbanditrydr]

Yeah.... 1 & 2 are being balanced at the same time but when you turn the screw one goes up and the other goes down and you want the two to be equal.

Quit thinking about target numbers and look for balance - equal heights of mercury regardless of what they show number-wise on the scale. 

[pmackie]

Hey lighter223

What I think your missing is the purpose of the carb balance. The whole idea is to get the throttle plates of all carbs to be the same. IE you want ALL the cylinders to be receiving the same amount of fuel and air. The easiest way to do this is to "balance" the vacuum at idle. The actual level of vacuum will be dependent more on total throttle opening (and therefore likely idle rpm)

Anyway, the guys have indicated the correct proceedure to balance the "pairs" of carbs. Once all carbs pull the same vacuum, then adjust the idle to the correct rpm.

[lighter223]

I understand the point but thanks for defining it anyway...

When I hook up  the manometer I dont get 1&2 at the same level and 3&4 arent at the same level...   

So when do I tune with the a/f screws before OR after the synch...? I would think before...

Wouldnt that give a balance between 1and2 and 3and4 then you match the levels as a set of 1&2 and a set of 3&4


and how exactly do you know when each a/f screw is at the right amount.  I can hear anything to notice a difference

[mademiriam]

your a/f screws do NOT set the balance, they may to affect it BUT they are not used to balance carbs. Let us know what the setup is on your bike, after market exhaust/jet kit or all original. That way you can get a ballpark of where your a/f screw should be. Set all four the same, then balance the carbs the way they are supposed to be balanced...  This just affect throttle opening NOT air fuel mixture.

[lighter223]

Everything is stock except the can which is a "matrix systems" or some crap... came with  the bike but sounds good  so I dont complain... I wish the person who put it on installed a jet kit. but what ever.. i will when I have money... air filter is stock ...

Nothing special...

The reason I am hesitating on changing the settings on the balance is because it was "near" balanced as far as I know...  and they havent changed... I was hoping to get it running then do the synch... the only thing changed on the carbs were the A/F screws, which is why I am fixated on them...

Sorry for being fixated but you know....

[pmackie]

I was hoping to get it running then do the synch...

Um...yup, get it running first.

As for starting point on air screws, with stock jetting and a slip-on exhaust, for a 2nd gen 1200 use 3.0 turns out, for a 2nd gen 600 try 2.5 turns out. This should get you in the ball park.

So...your post said earlier that the bike was firing on all cylinders. Will it start at all?