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motion pro sync tool,
- TeK9iNe
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I do use carb sync tools, but I'm very careful about how much I adjust the carbs AFTER I've synced the carbs on the workbench.
If you are dealing with an old set of carbs, the sync at idle can be influenced by wear in the carb. Air can leak past slides and idle passageways may not flow fuel or air the same as when new due to corrosion or gasoline deposits.
With Z1 and fully mechanical carbs (not a CV carb). I sync the slide heights with a thin round piece of metal (actually a partially unwound paperclip). Then when I make an vacuum adjustments I only tweak any one adjuster a very small amount (1/4 turn or less).
I adjust the air screws/fuel screws to help sync the idle more than any slide linkage adjustment
While a super smooth idle is nice, it's more important to have the slides fully sync'd when the needle / needle jet come into play in the mid range.
Superb info here! +1
ALWAYS bench sync. Then if a reading is very low vacuum when dynamic syncing, and you have to lower the slide very far to achieve sync, there is deffinately an air leak present between the slide and engine.
When the slide is RAISED to sync/or add more fuel/air on a carb @idle, the vacuum DECREASES.
When a mixture screw is tweaked closer to the best power mixture @idle, the vacuum INCREASES.
GL all.
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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- stonemaster
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- TeK9iNe
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I bench sync mine as well, i use welding wire .025, so i guess i bought the sync tool for nothing ... WANT IT BACK ????
Bench sync, before vacuum syncing.
Dynamic vac sync is absolutely necessary.
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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- Patton
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But air/fuel requirements for best performance varies among the cylinders, even if ever so slightly. So the carbs are used to achieve matching best performances among the cylinders.
Intake vacuum measures a cylinder's performance.
Thus, achieving equal vacuums also achieves equally performing cylinders.
Imo, the running carb sync procedure might be more accurately referred to as syncing performance among the cylinders by adjusting the individual carbs.
Good Fortune!
1973 Z1
KZ900 LTD
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- stonemaster
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- Motor Head
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Here is a thread I started 1 year ago, and there are a lot of good Ideas here for a home made set up. I still use the 1 I built for $6, although I have added some restrictors to each of the 2 hoses. These really work, and even the slightest movement of your adjuster will register with the ATF in your "Gauge".
1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
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- timebomb33
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1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
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- TeK9iNe
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this tool is a POS, Followed all instructions to the T, wouldn't even calibrate correctly, Lame, i can do better by ear, NEXT ....
Many people have been successful with this tool.
If it wont calibrate correctly, there is deffinately a setup issue as it can be done off the bike. Just hook the four lines into the 5-way tee and suck on the last opening watching the liquid rise up till about 1/2 way. Plug the hole with your tongue and then calibrate the levels with the screws around 1/3 height of the instrument. Works great!
I used to do the ear thing until I got a Morgan Carbtune Pro, then I realized how bad my ears sucked. :laugh:
GL.
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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- stonemaster
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- mark1122
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- Keep twisting it
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in order to get each slide the same i have to keep stabbing at the setting’s. I have rs34 carbs. dif carbs will have dif adjustment techniques. the rs carbs really need a FINER fine tuning setup. it is a bit of a pain and a guessing game to tune them. i just keep loosening the top screw, turning the adjuster (the smallest amount imaginable) then retighten the lock screw. u just keep over shooting , then repeating until u finally get it right.
The process is a pain but it it is not the fault of the gauges; they seem to be very accurate.
on some racks of carbs, 1 carbs slide is not adjustable. this is the master carb. all other carbs are set up to mimick the vacuum reading of this carb.
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