Good source for a carb sync tool (vacuum gauges)?

[marc]

Does anybody know of a good source in USA for
a 4cyl vacuum gauge, used to sync carbs?
Compression testers, any?

Just planning for a rebuild.

[starwalt]

Although I have never purchased tools from them, BikeBandit has a fair selection... here

That is the first one to come to mind. MotionPro makes many tools, but I do not know if they sell direct.

[marc]

Mercury columns or dial indicators?

I was thinking about something likehttp://www.holeshot.com/main/showimage.php?tools/images/tool_carb_sync_gauges.jpg

I know these idicators can be used to diagnose valve leakage, exhaust underflow, and so, but I'm unsure if the mercury columns will
provide same functionality.

Thankyou for your advice!

[goat]

I ended up buying a vacuum gague from an auto parts store for like $20. Probably overpriced, but I was really frustrated with my homebrew synch tool at the time so now I have a vacuum gague.

[scratch]

I've had the same MotionPro mercury carb sticks (the first yellow one, back when it was made by PCCC) for 15 years. I got mine for $50 from a local shop, I think you can get a better price than DK locally.

[Kerry]

From the Service Tools page on Motion Pro's website:

Economy Carb Tuner Part Number: 08-0010 Sug. Retail: $54.90



Deluxe Carb Tuner Part Number: 08-0009 Sug. Retail: $99.90



Lower prices from Chaparral:

Motion Pro Economy Carb Tuners (Part #315-0437, $35.99)

Motion Pro Mercury Carburetor Syncro Tuners (Part #315-0440,  $64.99)[/list:u]I own one of the "Economy" models.  I have nothing to compare it against, but it works fine for me.

EDIT: Dennis Kirk offers the same two gauges, but they call the Economy version  "Home Mechanic Carburetor Tuner" (Part #28-273, $52.99) and the other one "Shop-Quality Carburetor Tuner" (Part #28-274, $94.99).
I really appreciate the folks who shop with Dennis Kirk; they make it possible for DK to produce a really nice catalog.    But I rarely buy anything from them myself.  Now you know why....

[marc]

Thankyou folks!
Your time and your advice is appreciated.

Now the question is:
Is it better a dial indicator or a mercury column?

Thanks!

[Blueknyt]

i have another question for you marc, how often are you planning on Syncing the carbs? do you have alot of multi carbed engines?


here is something to think on.   You know how to use feeler gauges? ok, now using some single core wire or what i used is a torch tip cleaner (very stiff precise wire tool) you can syncronise all the carbs you want.


all you are doing is making all the carbs in the train open the same amount at the same time.  

the lead carb (one that rests on the idle stop screw) adjust it till the fine wire just passes between the throttle plate and the body. now go to the next carb in the chain. adjust the link screw till it fits, so on and so forth.   now this is where i open the throttle and let it snap shut a few times and recheck with the wire.   you can even do this by eyeball, turn the lead carb till you almost cant see any light comeing through the throat. then adjust the other to match it.  ive used this methode many many times on many bikes and it works well.  the sync tools allow you to do the same while on the bike. generaly once set, you dont need to mess with it again unless you take them apart from the rack.   just  something to mull over before droping the coin.

[marc]

Well, I don't have many engines, my brother has a Kawa ZZR6000
and I have a GS500, but from time to time, some friends or some
friends' friend comes around with an old bike thats been saved from
the salvage yard, or his grandpa's bike, that's been sitting since the
industrial revolution times, and needs to see if something can be
done.

This tool will not be abused, but will have more use than "just
being used a couple of times".

BTW, I'm experiencing problems with my GS500. Previous owner
of my GS500 was careless, and I bet that drove it with few oil several
times.  
I'm getting few power beyond 7000rpm, and that could be caused
by several issues:

- I'm getting the fuel starvation issue, so that I need to set my petcock
 to the PRI. This could be caused by a old/defective rubber valve in the
 petcock, or may be caused to few vacuum in the intake valve area.
 Leaking valve seats or leaking valve seals could be the cause.

- I'm getting crusty spark plugs. Not lean (white) and not rich (grey-black)
 but lots of soot and crust on the spark plug. Looks like burnt oil. This
 might point to worn-out rings, but since valve seals might be in bad
 condition, I may be suspecting about rings when it was seals' fault.

- I'm getting very poor mileage: 100 miles per full tank.

I'm sure that this tool will help me to diagnose what's the condition
for my engine, and avoid an always_expensive not_worth_the_money complete rebuild, since that tool will help to measure the vacuum of
my engine, and the valve leaks.

[marc]

Well, I've saved your way to sync carbs: it's pretty easy and will work
for sure in new engines , but should consider that:

- It is true that air flow is proportional to the area that it has to flow through.

- But it is true that air is compressible, and flow is proportional too
to the suction power, and when a valve seat or valve seal are leaking,
suction power will be less, or even a back-flow.

I expect that these gauges are good enough to see them "dancing".

You know Yamahas, and may remember the YEIS (Yamaha Energy
Induction System). It was just a resonator system that, helped by
the differences in intake air flow, it generated a wave that could
compensate a engine back-flow in 2-strokes engines, where back-flow
is quite common.

[scratch]

This tool will not be abused, but will have more use than "just being used a couple of times".

I only use mine after I do a valve adjustment every 4000 miles, which is about every 4 months.

- I'm getting the fuel starvation issue, so that I need to set my petcock to the PRI. This could be caused by a old/defective rubber valve in the petcock, or may be caused to few vacuum in the intake valve area.

...Too little vacuum in the intake valve area...you may be onto something there...I'm thinking (theorizing) about when I do my next valve adjustment and subsequent vacuum balance to allow my left carburetor to draw a little more vacuum than the right to help keep the vacuum actuated diaphragm in the fuel selector open.