Topic: Carb 1 completely out of sync

[ChopSticks]

Alright I've done the following:

Oil Change (oil/filter)
New Plugs (gapped)
Cam Tension
Adjusted Valves
New OEM Points Assembly (gapped and strobe light timed)
Carbs Cleaned
> Bench Synced
>Clear float tube leveled
>New fuel hoses
>New petcock
New Exhaust Boots
New Intake Boots
New K&N Airfilter
New Battery (AGM)

Alright F3 engine in 750K4 frame. (Carbs are from the early K model)

So to start I hooked up all of the gauges to carb 4. Gauge 1, 3, and 4 were pretty much in sync. 2 was -2 compared to the others, so I marked as is.

Then hooked them all up and fired her up.
3 & 4 was hitting around 9
& 2 was hitting around 7 (which makes sense with the -2 variance)

So 2, 3, 4 seem to be in sync, but 1 was hitting around 15. No matter how much screwing of the Throttle Stop Screw or adjusting of the jet needle it Carb 1 wouldn't get any lower. I've double checked the main and pilot jet and both appear to be clear (I can see light through them). I also switched 1 & 4 gauge assuming maybe my initial baseline calibration was off, but once I switched them 4 started to read around 15 and 1 started to read 9

Here's a video:
At the beginning bike is idling at 900-1,000 and then revved to ~2,500-3,000 (twice)

[Jimray23]

Did your synchronizer gauges come with the plastic valves? If so you should install them. It will make it easier to read the gauges. You need to check to see which of your carbs is the primary carb and try to adjust all carbs to that one.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[Deltarider]

Didn't your synchronizer come with instructions how to use it? Those needles need to be dampened. Nobody can synchronize with needles moving that wildly.

[flybox1]

Your bench sync sucked, if they are that far out 
+1...install the vacuum gauge dampeners.
+1...calibrate your gauges by putting each one (one at a time) on #1 carb....and adjust them all to read the same vacuum.
The actual value on the gauge can be ignored for the purposes of calibrating the gauges.  get them all the same.

[ChopSticks]

Did your synchronizer gauges come with the plastic valves? If so you should install them. It will make it easier to read the gauges. You need to check to see which of your carbs is the primary carb and try to adjust all carbs to that one.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

Ah yes they did come with plastic valves. But unfortunately no instructions

Very similar to this

http://www.bluemaize.net/im/automotive/carburetor-synchronizer-6.jpg

I see images that have the adapters between the hoses (assuming I'll have to cut the hoses?) but also other images where the adapter is between the hose and the gauge valves? (no hose cutting required)

How can I find out which is the primary?

[ChopSticks]

Didn't your synchronizer come with instructions how to use it? Those needles need to be dampened. Nobody can synchronize with needles moving that wildly.

I thought that too but I was basing it off this video

where it shows just to pick the highest needle position. I'll add the dampers this weekend, thanks

[Jimray23]

Can you post a pic of your carbs? Yea i just cut my hoses at about 1 1/2 inches from the gauges and put them there.

--------------------------------------------------
Jim
I really don't see why people ask for advice if their not going to take the advice given.

[ChopSticks]

Your bench sync sucked, if they are that far out 
+1...install the vacuum gauge dampeners.
+1...calibrate your gauges by putting each one (one at a time) on #1 carb....and adjust them all to read the same vacuum.
The actual value on the gauge can be ignored for the purposes of calibrating the gauges.  get them all the same.

Don't think I can actually adjust the calibration on each individual gauge on this one. would it be sufficient just to find the difference and mark accordingly? or do I need a new set of gauges?

[flybox1]

Your bench sync sucked, if they are that far out 
+1...install the vacuum gauge dampeners.
+1...calibrate your gauges by putting each one (one at a time) on #1 carb....and adjust them all to read the same vacuum.
The actual value on the gauge can be ignored for the purposes of calibrating the gauges.  get them all the same.

Don't think I can actually adjust the calibration on each individual gauge on this one. would it be sufficient just to find the difference and mark accordingly? or do I need a new set of gauges?

Each gauge has a small flathead screw on the dial face....that is the adjustment screw.

[Jimray23]

Your bench sync sucked, if they are that far out 
+1...install the vacuum gauge dampeners.
+1...calibrate your gauges by putting each one (one at a time) on #1 carb....and adjust them all to read the same vacuum.
The actual value on the gauge can be ignored for the purposes of calibrating the gauges.  get them all the same.

Don't think I can actually adjust the calibration on each individual gauge on this one. would it be sufficient just to find the difference and mark accordingly? or do I need a new set of gauges?

Each gauge has a small flathead screw on the dial face....that is the adjustment screw.

Yep just take the clear cover off and that will give you access to the screw.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[Deltarider]

Wait with this 'calibrating' until it's clear your gauges need it. Just connect the gauges one after the other (and not simultaneously!) to the same vacuum source and compare the readings.
Are you sure valves cyl #1 are correctly set?

[Jimray23]

Here's a shortcut to video. I don't agree with all his opinions but this seems pretty accurate.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[flybox1]

Guessing if he checked his dial gauges against just one carb, and made sure they were all pulling the same vacuum(calibrating) he might not have found such a different reading once he hooked up to the mercury gauges....

[pjlogue]

In reading your original post, you refer to adjusting the idle stop screw and jet needle.  You need to be adjusting the slide nuts at the top of the carbs or cable adjusts if you have very early set of carbs with 4 cables attaching to the carbs. Also, you need to put the snubber valves in line with each vacuum line and locate it near the carb, not near the gage.

-P.

[Jimray23]

In reading your original post, you refer to adjusting the idle stop screw and jet needle.  You need to be adjusting the slide nuts at the top of the carbs or cable adjusts if you have very early set of carbs with 4 cables attaching to the carbs. Also, you need to put the snubber valves in line with each vacuum line and locate it near the carb, not near the gage.

-P.

Emgo suggest near the gauge. Heres some instructions.

http://img.jpcycles.com/staticwebfiles/instructions/pdf/zz40036.pdf

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[ChopSticks]

Can you post a pic of your carbs? Yea i just cut my hoses at about 1 1/2 inches from the gauges and put them there.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

Carbs look like this (not my pic)

[ChopSticks]

Wait with this 'calibrating' until it's clear your gauges need it. Just connect the gauges one after the other (and not simultaneously!) to the same vacuum source and compare the readings.
Are you sure valves cyl #1 are correctly set?

Yes I originally connected all gauges to Carb 4 and found that the second gauge was reading -2, guess I'll do it again with the dampers

As for the valves. Pretty sure they're correctly set, the bike hasn't really moved since. but I'll add this to the list also

[ChopSticks]

Here's a shortcut to video. I don't agree with all his opinions but this seems pretty accurate.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

Thanks I noticed he mentions and also have read in other places there's a main carb #2, but all my carbs have a throttle stop screw adjuster, how can I find out which is the main? Curious what opinions don't you agree with?

[Jimray23]

For these carbs, adjust the nut in the center on top to sync. If #1 won't meet the others then adjust #'s 2,3and 4 to #1. As u adjust 2,3 and 4, #1 will begin to change and you will also have to adjust the idle speed some, usually.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[Jimray23]

Yours don't actually have a main, they are all adjustable.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[ChopSticks]

In reading your original post, you refer to adjusting the idle stop screw and jet needle.  You need to be adjusting the slide nuts at the top of the carbs or cable adjusts if you have very early set of carbs with 4 cables attaching to the carbs. Also, you need to put the snubber valves in line with each vacuum line and locate it near the carb, not near the gage.

-P.

yes I was adjusting the slide nuts which makes the needle go up or down right? I was adjusting about quarter turn at a time. If I recall if I did a full half turn the bike would die, so I turned the other way and the bike was revving high. So I just put it back to the original position and adjusted the throttle stop screw which didn't do much with the vacuum

Emgo suggest near the gauge. Heres some instructions.

http://img.jpcycles.com/staticwebfiles/instructions/pdf/zz40036.pdf

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

Thanks! I'll print these out

[Jimray23]

Mainly i just don't agree with his float setting. He sets them as if all floats are new and couldn't get old. He say don't do the clear tube test. I think its necessary because all things age.

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Jim
I really don't see why people ask for advice if their not going to take the advice given.

[pjlogue]

In reading your original post, you refer to adjusting the idle stop screw and jet needle.  You need to be adjusting the slide nuts at the top of the carbs or cable adjusts if you have very early set of carbs with 4 cables attaching to the carbs. Also, you need to put the snubber valves in line with each vacuum line and locate it near the carb, not near the gage.

-P.

Emgo suggest near the gauge. Heres some instructions.

http://img.jpcycles.com/staticwebfiles/instructions/pdf/zz40036.pdf

--------------------------------------------------
Jim
I really don't see why people ask for advice if their not going to take the advice given.

 

You want the tubing volume (Volume of air inside the tube) to act as a capacitor for the vacuum pulses.  Putting the snubbers close to the carbs allows for steadier needles because you have a larger volume of "dampened" air if the tubing between the gage and the snubber is long.

-P.

[Jimray23]

Mine smooth out with no issues. You can download the emgo instructions and there's a pic showing them up close to the gauge. The way i do it. If you turn the little knob and it doesn't help enough, turn it a little more. Until u like it. I have all four of my carbs set to 9 inches of water. Within a 1/4 inch of each other.

--------------------------------------------------
Jim
I really don't see why people ask for advice if their not going to take the advice given.

[pjlogue]

In reading your original post, you refer to adjusting the idle stop screw and jet needle.  You need to be adjusting the slide nuts at the top of the carbs or cable adjusts if you have very early set of carbs with 4 cables attaching to the carbs. Also, you need to put the snubber valves in line with each vacuum line and locate it near the carb, not near the gage.

-P.

yes I was adjusting the slide nuts which makes the needle go up or down right? I was adjusting about quarter turn at a time. If I recall if I did a full half turn the bike would die, so I turned the other way and the bike was revving high. So I just put it back to the original position and adjusted the throttle stop screw which didn't do much with the vacuum

Emgo suggest near the gauge. Heres some instructions.

http://img.jpcycles.com/staticwebfiles/instructions/pdf/zz40036.pdf

--------------------------------------------------
Jim
I really don't see why people ask for advice if their not going to take the advice given.

Thanks! I'll print these out

A quarter turn is a LOT!  Do it gradually and slowly.  You want to have about ~2-3 threads showing on the adjusting rods above the smaller lock nut.  This should give you room to work with.  You want to be sure all your carb to intake pipe boots are tight and not leaking air. 

-P.