Carb sync tool

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rayray76
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Carb sync tool

#1

Post by rayray76 »

Hello all, perhaps this has been asked before, where is the best place to find the old style mercury carb sync tool, or perhaps there is something new and improved??? thnx
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robin1731
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Re: Carb sync tool

#2

Post by robin1731 »

1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
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ritalz
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Re: Carb sync tool

#3

Post by ritalz »

Not likely to find mercury stix anymore because mercury is classed as a dangerous item. You can get a set of gauges from some of the suppliers on the web.
Al

2003 Goldwing Daily Rider
1975 Goldwing 'Max'
1984 Goldwing New Bagger Project
1976 Goldwing 'Grocery Getter' Sold
1985 Goldwing Interstate 'NCC-1985' sold
1981 Silverwing Sold
1982 Goldeing Project Sold
1981 Goldwing Parted Out
1983 Goldwing Project Sold
1973 CB500F Long Gone
1966 CL77 First Street Bike
http://www.ngwclub.com/gallery3/index.p ... ans/ritalz
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rjdoles
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Re: Carb sync tool

#4

Post by rjdoles »

When I had my Shadow's I made a u-tube manometer for about $25. I made it from a 25' length of 1/8" clear plastic tubing that I purchased from one of the home improvement stores. See picture.

I drilled holes about every foot along both sides of the 6' length of a 1 x 2" to feed wire ties through that will secure the tubing. The center of this 25' length of tubing will be attached to the bottom of the 1 x 2" and then wire tires will secure the tubing up both sides of the 1 x 2".

You probably need a restriction to slow the motion of the fluid. I cut a 1" length of a brass bolt. I drilled a 1/32" hole through the bolt. I cut my plastic tube at the midpoint and inserted the restriction into the two cut ends. It is important that the restriction is at the bottom of the U so that it restricts the fluid movement. Fluid is not compressible and the air above it is.

You could use water but I preferred a colored liquid so I used automatic transmission fluid. It has a specific gravity of about .87 and I added it until it filled the bottom of the u-tube to about 30" on either side of the 1 x 2". ATF is about 1/16 of the specific gravity of mercury so the fluid height difference between the sides of the u-tube makes this manometer is about 16 times more sensitive than if you were using a mercury based manometer.

I ordered MotionPro 5 mm adapters for about $10 on Ebay which match the fittings on our carb elbows. I drilled a hole in the top of my 1 x 2" and hooked a coat hanger through it and hung my manometer from a rafter in the garage.

I start synching by threading the MotionPro adapters into the right side carb elbow's 1 and 3 which are supposed to be adjusted first and then I adjust to get the balance within an inch or two. Remember that using ATF makes this about 16 times as sensitive as a mercury manometer so don't try to get them perfect. I move the MotionPro adapters to carb elbow's 2 and 4 and adjust the left side balance to within an inch or two. I then move the MotionPro adapters to elbow's 3 and 4 to adjust the left/right balance to within an inch or two.

I am happy with the results.
manometer.jpg
manometer.jpg (122.98 KiB) Viewed 365 times
Started with an Allstate stooter made by Cushman and then a series of Honda motorcycles. 305 SuperHawk, CB750, VT600DC, VT750CD and then 4 years ago I left motorcycles for scooters with an Elite 125, Reflex 250 and Silverwing 600. Most recent is a barn find 77 GL1000 that I plan to resurect.
yawjansen
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Re: Carb sync tool

#5

Post by yawjansen »

Working with a "Carbtune Pro" myself. I'm a bit of a newby but it seems to be doing the trick. Simple to use and all mechanical. The DIY ATF syncs look cool but you end up spending a lot of time gathering parts and messing with them etc...witch might be your thing! Haha! Plug and play is nice in my book.
1979 GL1000 Early Stages of Rebuild 08/01/2020 First Shot at it!
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Jonesz
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Re: Carb sync tool

#6

Post by Jonesz »

Just bought a Digi-synch. Very cool tool. Took less than 15 minutes to do my 78 gl1000 and now have no popping/miss at idle. Not cheap but have a couple of buds who pitched in some $. One of them, a mechanic used it yest to tune his 4 cyl merc boat engine. He thought it was a great way to synch the carbs. You would need to buy 4 (5 mm adapters to do flat fours with 4 carbs)
Jonesz

1983 GL1100 Aspencade named "Freki" currently undergoing change to a standard. Sold
1999 Valkyrie CT 1500 goes by the moniker "Valerie"
1978 Gl1000 "Loki" new project going to be a Cafe Convertible
1979 Suzuki GS850. Sold
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Dr. Frankenstein
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Re: Carb sync tool

#7

Post by Dr. Frankenstein »

I use a Morgan Carbtune II; I've had it for some time and used it successfully in my 1985 Virago 700 and my KZ650; stainless steel tubes, so no worries about sucking fluid into the chambers. Kind of pricey ($100), but well worth it, I think.

https://www.carbtune.com/
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desertrefugee
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Re: Carb sync tool

#8

Post by desertrefugee »

I also use the Carbtune. Absolutely wouldn't give it up for anything. Although hundred bucks is steep, for me it has been amortized across a bunch of motorcycles. It has paid for itself many times over.
- Life is not about waiting for the storms to pass. It's about learning to ride in the rain.
rayray76
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Re: Carb sync tool

#9

Post by rayray76 »

Thanks for the replys, appreciate the feed back.
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