cheap UK carb balancer

this is the best carb synchronizer i've ever had. cheap at $30, shipping from the UK included. no electronics, just basic stuff.

never before had my airhead been so smooth...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&viewitem=&item=230145076260



usual disclaimers apply. i'm just one happy customer...

i am assuming, after such a glowing report of a new product that you will not have too much trouble posting the pictures of the said unit in action? i am curious. especially on how it works on four cylinders.

invent a better moustrap....

i bought a really nice synch gauge from mac tools and whenever i have a bike that will not seem to dial in nice i switch to my 25 year old mercury set. never needs calibrating. so when i see something like this it definately gets my curiosity up.


so junkie, post them damn pictures!

coming... coming... over the weekend folks!

here's the unit strapped to my left grip. i should make another stand to isolate the unit from the bike's vibrations and handlebar movements. i use a re-usable tie strap so i can tighten it and align it as centered and completely vertical. but i guess a small error wouldn't really matter. i'm just too anal at times

the left hose goes to the left carb's vacuum take-off and the right to the right. the right carb is my "basis" cylinder, setting it up as per textbook adjustments. adjust the left carb to give the bike a somewhat good idle (engine hot, of course).

see the 2 steel balls resting in the bottom-center? the upper ball doesn't move (don't ask, i don't know why) as it is the basis or target for alignment of the bottom ball. at idle speed, engine hot, the lower ball will oscillate left to right, with a gap of about 1/2-2/3", and the oscillation may be to the left or right relative to the upper ball. simply adjust your left carb's idle screw until the center of the oscillation is aligned with the stationary upper ball. if you're turning the idle screw the wrong way, the oscillation will move even further from the upper ball. very simple.

when done, it's time to adjust the cables. i like using the range of 1000-2000 rpm as the testing range. loosen the 10mm locknut of the left cable and again at about 1500 rpm. check where the lower ball is relative to the upper ball. it's even easier this time since at rpms above idle, the lower ball stays steady thus, is easier to "read". simply turn your left cable adjuster until the lower ball starts to move towards the direction of the upper ball (i had a steady hand on the throttle at 1800 rpm while adjusting the left cable). adjustment is done when both balls are aligned. secure the locknut thereafter. even more simple.

it amazed me that after adjusting the cables, the lower ball stayed steady for the big rpm range i tested it (from off-idle to 4000 rpm). or maybe my cables are brand-new (i foresee repetitions as cables strtech when new)? a noticable improvement was on the dreaded R100 vibrations at 4-5000 rpm.

questions i can't answer:

1. why the upper ball doesn't move.
2. if the left and right hoses are just one hose (i never bothered to check).
3. no, i didn't try rolling the steel ball out of the hose.
4. how the right cyl became the reference cyl.

What's that other tube attached at the top of the coil?

There's a bulge on the left side, is it a union or an ending?

well, I think the fact the right cyl is the reference cyl is why the ball doesnt move.
they would have to be the same hose, in this set up, or how would one "see" what the other is doing.... but maybe that bulge is a valve of some sort, (as well as a coupler) to keep the upper ball from showing a lot of movement.
I think you could set either carb up as the reference carb, just swap the hoses.

Your carbs should be self-synching above idle, unless as you pointed out, the cables are differently elastic, and yeah, you'll have to adjust them as they stretch.

I find my R100 to like the 4-5500 range the best for sound and cruising.. then again, my bike's prime vibration range is 0-7Krpm, and it REALLY doesnt like more than that.

This procedure is similar to Bings, but I think they do the cables first. I cnt remember now.

If you read the ebay description, the upper ball is like a plumb bob and just indicates the lowest point in the upper hose. The vacuum pulling left and right on the lower hose will move the ball if one carb is sucking more air than the other. When both a drawing the same; the ball stays centered under the upper one.

The reference cylinder is the one with the idle screws, which on an airhead is either one. So you could make the left one the reference if you want.

oic! that makes sense. So the upper hose is just a small loop? that would explain the bulge. wait no it doesnt.

I presume the ball's big enough not to get sucked into the vaccuum take off if you pull one side before you shut the bike down.

Probably another bulge on the right side, concealed by the wrap. I'm sure that there is a retainer of some sort to keep the balls in the hoses.

Someone asked earlier about 3 and 4 cyls. On my Concours, the base is #3. Sync 3 to 4. Move the hoses to 1 & 2. Sync 1 to 2. Move the hose from 2 to 3. Sync 1 to 3. Done.

the top it appears to be just a band to keep the hoses together. on the left side, it looks like a sealed ending.

i suppose it doesn't really matter which is done first. i would think the idle screws and the cables are really independent of each other (if set-up correctly to begin with).

i will check again later and have a close look at the "bulges". maybe i should try to roll the balls out

as mentioned, the bulge is probably just a joining of tubes and/or something to prevent them from getting sucked out.

Looks like a nice idea to use balls instead of liquid for the same type of setup as the $5 carb balancer that we've all seen (i hope) kicked around here.


Maybe the stationary ball is simply in a closed loop that isn't connected to the tube that is connected to the carbs.
That way, gravity centers it and that's your visual reference for the other ball which is in a separate tubing line which DOES move due to vacuum imbalance and IS connected to the carbs.


Looks like it might be very very easy to just make one of these. Make one closed loop tube and stick in a small ball. It doesn't attach to either carb, so just close it and you're done.

Then, make a normal 15-20 foot tube with a section in the center of it made of larger tubing than the rest of the 15-20 feet and put a ball in it that is small enough to move around, but large enough to not get sucked through the long (smaller diameter) ends and end up at or in the carbs.


I'm gonna have to make a trip to the hardware store now. Whoohoo!

i think you got it, datchew! now i feel suckered for shelling out $30! :huh


on a separate note, my cables are brand-new as mentioned. and they seem to go out of synch every 200 kms or so. i know they stretch but is what i'm experiencing more of the norm? after how long will they finally stop stretching themselves?

Don't feel suckered man... nobody could have looked at that on ebay and figured that out. I wouldn't have without your explanation and the other fellas tossing out ideas.


This just means that a whole bunch of advrider cheapskates (who's the president of that by the way... still Solo Lobo?) are gonna be building these and perfecting them...um, hopefully.


I figure you introducing it is worth at least several beers from each of us whenever we meet up. Put me down on your "he owes me" list for a couple of good pints. Which is the same as a case of PBR junk!

I agree with datchew - we owe you for the data! It's a cleverly simple solution that I never would have figured out from the ebay listing. If 30 of us mailed you a buck, you'd be re-embursed. I'd do that - give me your address.

How about dissecting it for us - and give us all the dimensions?

I've never recorded how long it takes for cables to settle in, but if you replaced both, they should both be stretching the same amount. Do you have them routed with the smoothest bends and no kinks? Come to think of it, I only recall replacing clutch cables, but I've got a set of throttle cables for one of my bikes that are too short that I'll need to replace soon. If you can wait, I'll let you know.

you're on!

reminds me of this thread somewhere (in old school?) wherein someone asks around for suggestions for a dualsport for his son who did a tour of duty in iraq, and currently in afghanistan. he even posted his son's photo in uniform then an appreciative patriot started "passing the hat" around with his initial donation of $100. everyone was chiming in and wanted to do the same. by now i suppose the son has a 1200 adventure with vario top and side cases and all the touratech farkles! all i'm saying is you guys are going too cheap on me! like i'm some soon-to-retire hooker :huh

yeah, i'll do some measurements soon. shouldn't be complicated.

i routed the cables to where the original cables were routed. i suppose that was the "factory route". now that the cables are stretching, it's not enough that i tweek on the left carb. the right cable has also stretched that i have to tweek it as well prior to synching