Anyone have any experience of these cheap £25 Chinese balancing gauges on Ebay? Worth the money?

They're a knockoff of the original Davida ones. As to whether they are worth the money... if you do the following then the answer is probably yes.

- Warm the engine up to a steady temperature. If you don't do this, the revs will change during testing
- Connect one gauge to one cylinder
- Take the reading
- Connect a second gauge to the same cylinder
- Take the reading
- Repeat for 3 & 4. If they match, you'll probably win the lottery this weekend
- Take the one with the lowest reading and try to match the other three to it
- If that fails, take the second lowest and rinse

Don't ask why 'lowest' because at this point that information is a fading ghost on time's arrow. Balance your TBs and prepare for the ballsache when they are done. Repeat the first five steps above to make sure that none of the gauges have slipped out of sync. When you've done this two or three times and they haven't slipped, you can consider starting to trust them. Also: do steps 1 - 5 before each session to be sure you are working with synched gauges. It really doesn't take long - the bike will object to having a vacuum port uncovered but it won't stall so no stop-starting.

I've had my Davidas for around 40 years now. They've been bashed, battered, stripped and cleaned numerous times but once they're synched before a session, they stay synched.

Or you can spend maybe 5 quid for a couple glass bottles(the vacuum will collapse plastic), two stoppers with holes in them, some brass tube and a couple meters of plastic tubing.  Way more accurate than mechanical gauges.

The operating principal is that the fluid will flow to the bottle with the higher vacuum.  It's amazing how sensitive and easy to use this rig is.  I can set the vacuum so the fluid levels don't move for a minute or longer.

Connect one bottle to the last cylinder and adjust the air screw for 1 1/2 turns out from lightly bottomed.  That is your reference cylinder.


Connect the other tube to one of the other throttle bodies and use the air screw on that throttle body to adjust the vacuum so there is no change in the fluid level in the bottles.  When the level is steady, the vacuum is perfectly matched on the two cylinders.

Repeat for the other throttle bodies.  Whole job should take less than 10 minutes. 

If you do go for the ChiCom gauges, I would suggest an easier calibration procedure.

Get a manifold that will allow you to connect all four gauges to the same throttle body.  The manifold can be as simple as a daisy chain of three plastic tubing tees.  I like to use the last cylinder with the vacuum line to the fuel pressure regulator as my reference. 

Start the engine and adjust the air screw on that throttle body for 1 1/2 turns out from lightly bottomed.  Look at the gauges.  Are they reading the same?  They should, but I doubt they will. 

With the engine idling, put a small piece of masking tape on each gauge and mark the needle position.

Now separate the gauges from the manifold and connect them to the cylinders.  With the engine idling adjust the air screws so all the needles align with the marks you made on the tape.  Don't pay any attention to the reading on any of the gauges.

You've possibly missed it, but the small screw at about 5.30 on the gauge face is the needle adjustment screw. The 'glass' (plastic) face just pulls off. Unlike my Davidas, these appear to have knurls on the bezel which should make that operation a lot easier.

Point-Seven-five wrote:Don't pay any attention to the reading on any of the gauges.

Yes. I meant to add that you're just trying to get the needles to line up. It's a hell of a lot easier than trying to set the carbs up on some Japanese and Italian bikes when the needles have to indicate a given reading at a given set of revs.

How steady are the needles? 

I have a vacuum gauge that the needle vibrates over a 1cm span when the engine is idling.  Do you just "eyeball" for the center of the blur?

When I started syncing TBs I used to use a TwinMax but it was a PITA because I had to sync 1-2, then 1-3, then 1-4 and then recheck. I swear mine cost me a lot less but now they're $150+.


Then I broke down about 10 years ago and bought a Morgan Carbtune. I paid $100 and they cost $129 now. Very simple and quick. Worth every penny. Wish I'd just bought that in the first place. So quick and easy that anytime somebody brings a K by my house I give them a free TB sync.

A nice thing about the Carbtune is that it hangs from the clutch grip making it very easy to see/compare while you're syncing.


(The number 4 tube is not registering because that pic is on a K75.)

Motion Pro makes one but the inmates over at ADV have a pretty low opinion of it.

Out of curiosity I looked at the Chicom vac gauges over at Amazon and none of them have very good ratings. I would not go that route.

JM.02

Different strokes...

The $90+ I saved with my balancer bought the gas for a trip around Lakes Huron and Superior.

Point-Seven-five wrote:Different strokes...

The $90+ I saved with my balancer bought the gas for a trip around Lakes Huron and Superior.

The Carbtune costs less than one night of hookers and blow.

duck wrote:

Point-Seven-five wrote:Different strokes...

The $90+ I saved with my balancer bought the gas for a trip around Lakes Huron and Superior.

The Carbtune costs less than one night of hookers and blow.

Well if that's your hobby...

duck wrote:The Carbtune costs less than one night of hookers and blow.

Hookers and Blow have an office on Aurora Ave in Seattle.    So that is where you go to abuse clutch push rods? I'm asking for a friend undertaking a spline lube for the first time.

This one is pretty cool.  Hook it up to a laptop via USB:



https://promototools.myshopify.com/products/motorcycle-diagnostic-tool

Laitch wrote:

duck wrote:The Carbtune costs less than one night of hookers and blow.

Hookers and Blow have an office on Aurora Ave in Seattle.    So that is where you go to abuse clutch push rods? I'm asking for a friend undertaking a spline lube for the first time.

Heck! I did it right in my back yard with the whole fandamily at home! BTW I knew immediately who you were talking about!

Point-Seven-five wrote:How steady are the needles? 

I have a vacuum gauge that the needle vibrates over a 1cm span when the engine is idling.  Do you just "eyeball" for the center of the blur?

No reducer on it, I guess. The ones the OP links to and my Davidas have a screw-thread damper in the line that allows you to smooth out the pulses. I can get mine to pretty much rock steady. The one on mine is inline per gauge; the picture on the OP shows a 90 degree turn with the damper knob at the back of the pic.

Laitch wrote:

duck wrote:The Carbtune costs less than one night of hookers and blow.

Hookers and Blow have an office on Aurora Ave in Seattle.    So that is where you go to abuse clutch push rods? I'm asking for a friend undertaking a spline lube for the first time.

Yeah, it's very convenient.  I can drop my bike off Vallantine Motor Works at 3909 Aurora, pay them to abuse my clutch rod and then walk up the street to party.

Once you've finished there, you can head on to dentists Blood, Payne and Feare to have your missing teeth replaced. After, you could then engage Sharkey and Slye to take legal action against... well, whoever forcibly removed your teeth at the  party.





(Yes, both companies exist in the UK!)

Thanks guys interesting comments. I found on youtube a French fella setting up a customised K100 with what looked like identical cheepo Chinese gauges and what I think is a good result, so will invest £25 and give them a go.
https://www.youtube.com/watch?v=1qEZvKVMuP8