Topic: Carb stix v. Carbmate v. Twinmax v. CarbTune...

[historicjake]

Hate to bring up the subject of carb syncing but it is that time of year...weather turning, birds singing...

I have for years used a carb stick with mercury with frustrating success by feel that now it is time to move on.  Always having to be so carefull with the thing drove me nuts and the restrictor holes were not all the same size causing bad readings.  Having kids and a wife and mercury in one household is too much, so one has to go, see you later carb stick.

I'm looking for real world experience with other tools, from gauges to electronics,
Are the expensive ones worth it?  Just take it to a shop and let them do it?  Do it by ear or by exhaust pressure? 

By answering you may bring on riding season a bit sooner.

[GroovieGhoulie]

I bought a carbtune and love it.  Easy to use, accurate and not too expensive.

[cd811]

good thread...
I got to but something myself...
what is not too expensive?

[GroovieGhoulie]

good thread...
I got to but something myself...
what is not too expensive?

I paid about a hundred bucks for the carbtune, hoses, fittings, buffers, carry case (Necessary, IMO), adjustment tool.

[TwoTired]

I bought gauges (4 dials) in 1975 for $50.  I didn't use them again for 5-7 years.  Later, when I began collecting bikes, I used them on each one.  And, I was glad to have them.

If I only had one bike and never planed to work on more of them, I'd let the shop do it. 

Oh, who am I kidding?  I love tools and fixing it myself too much to have a shop work on my bike.

I don't believe you can do a proper sync job by ear or by exhaust pressure.  Maybe on a two cylinder engine, but not four.

Cheers,

[ofreen]

Oh, who am I kidding?  I love tools and fixing it myself too much to have a shop work on my bike.
Cheers,

The way I've always looked at it is this - You can pay the shop to do it (and hope they do it right), or you can pay for the tool and do it yourself.  And when you are done, you still have the tool.

[Steve F]

Oh, who am I kidding?  I love tools and fixing it myself too much to have a shop work on my bike.
Cheers,

The way I've always looked at it is this - You can pay the shop to do it (and hope they do it right), or you can pay for the tool and do it yourself.  And when you are done, you still have the tool.

Amen to that!  I have the 4 gauge (mechanical gauges) setup myself.  Never had anything else, but I'm satisfied with it.  I did find it necessary to calibrate them before I use them by simply attaching all of the gauges to a common vacuum source and adjust them to read the same across all four.  I use a vacuum generator on the compressed air line to make the vacuum for calibration.  What's nice about the mechanical gauges is you can lay them on the floor, across the handlebars, turn them everywhich way and not worry about spilling some toxic substance. 

[kaysystems]

I used to use the 4 guage setup, until one day when I was having trouble getting resulte & swapped the tubes on 1 & 4. Different readings. After some  investigating I found that the 4 guages were giving different readings, even though they all started exactly at zero.

I bought a carbtune & never looked back. You can even drop it without worry

David

[bwaller]

I've got gauges too and prefer them. It is wise though to check each gauge, I have 1 @-1" and 1@+1", but just marked the face accordingly to remind me.

[TwoTired]

I use a Mity-vac and a 5 way manifold to check my guages before use.  About ten years ago, they starting behaving oddly and sticking.  The mechanical movements inside the dial were greased and that grease had hardened.  A bit of a solvent flush and some Lubriplate had them all working predictably again. 

Did I mention I bought these new in 1975?  So, they've cost me  $1.61 per year to own and use...so far.  Okay, if you add in the cost of the Mity-Vac and lube, it was maybe $2.50 per year.  But, that doesn't include storage costs.

I wonder what percentage of my house I should attribute to that tool's storage?  Then again, my house is worth nearly 5 times what I paid for it.  So, what ever the storage costs, it would be a negative number when applied to tool storage.

Um...What was the question?   

[cd811]

ok... so where are you guys buying these tools?
I've put it off long enough

[historicjake]

Here's what I'm talking about, not nesssessarily the lowest price...

http://www.aerostich.com/catalog/US/Electrical-p-1-c-270.html

http://www.carbtune.com/

http://www.motionpro.com/parts/tools/product/deluxe_carb_tuner/

Motion pro has a cheaper version...

Hasn't anyone tried the all electronic systems...perhaps in a shop?  And how does a shop do it ?  Or for that matter, racers???

[cd811]

the carbtune looks like the deal...I've used the motionpro set-up many times...the carbtune looks easier to use(and a better deal)
what about the dial guage set-ups?

[Jay B]

Hasn't anyone tried the all electronic systems...perhaps in a shop?  And how does a shop do it ?  Or for that matter, racers???

I've been using a twinmax for about 5 years now. I like it a lot. I think they are about $100 including fittings to adapt to the vacuum ports. You can adjust the sensitivity up or down, highest is ridiculously sensative. My Oilhead BMW has a wonky bellcrank/two cable system to run the throttle bodies. It's very sensative to throttle synch, and needs to be done pretty often so I wanted something accurate without any mercury to spill. If anyone's interested I think I have the phone number someplace still.

[itsahonda4]

OK - so I was given a set of carbstix but the mercury appears to be low....
Where do I find liquid mercury? Certainly not home depot or wallymart I suspect.....
Al

[Tom in Newcastle......Ontario]

OK - so I was given a set of carbstix but the mercury appears to be low....
Where do I find liquid mercury? Certainly not home depot or wallymart I suspect.....
Al

Do you know a HVAC person....some thermostats have mercury switches in glass tubes....put it in a zip lock bag to prevent the stuff from going all over......just be careful as we all know mercury is not the healthiest crap........

[Mooshie]

I have this, love it.  Never had any problem tuning Dash properly
https://www.dimecitycycles.com/motorcycle-carburetor-vacuum-gauge-synchronization-kit-for-twins-and-fours.html

[pjlogue]

I think the carbtune is the best I have tried.  Very simple, rugged, accurate, reasonably priced and easy to use.  The only drawback is the snubber tube that came with it should have been longer.  I cut the tube in 4 exact equal lengths and I would like them to be a tad longer to further reduce flutter. 

-P.

[BomberMann650]

Finding a carbtune at a swap was the best addition to the toolbox.

Use it in any bike with more than 1 carburetor. 

Hell, it even works upside down!

[brewsky]

Use it in any bike with more than 1 carburetor. 

 

What about a single cylinder with twin carbs?

[toomanybikes]

Thanks all. I've been using a DIY system for a few years now that works ~OK on twins, but with four 4-cyl bikes currently in the stable it's time for a real tool. Carbtune it is

[ekpent]

I think the carbtune is the best I have tried.  Very simple, rugged, accurate, reasonably priced and easy to use.  The only drawback is the snubber tube that came with it should have been longer.  I cut the tube in 4 exact equal lengths and I would like them to be a tad longer to further reduce flutter. 

-P.

  Did your carbtune come with the the inline restrictors and were they put in at the proper spots ?  Don't have flutter problems with mine.

[pjlogue]

I think the carbtune is the best I have tried.  Very simple, rugged, accurate, reasonably priced and easy to use.  The only drawback is the snubber tube that came with it should have been longer.  I cut the tube in 4 exact equal lengths and I would like them to be a tad longer to further reduce flutter. 

-P.

  Did your carbtune come with the the inline restrictors and were they put in at the proper spots ?  Don't have flutter problems with mine.

Yes.  The thin, very small bore tube that came with the kit, I cut into 4 equal length pieces.  These were put in line with the rubber tube and about 4" from the end where it connects to the carb adapter tubes at the carbs.  The flutter isn't real bad but I'd like to see it less.  When the bike is in low idle the flutter is annoying.  I guess I could either get longer snubber tubes or longer snubber to gauge tubes so they have more "capacitance" 

-P.

[carnivorous chicken]

I used a mercury tool for years and liked it, but switched to a Morgan carbtune and won't go back.

I know some people say they are OK, but I had a Motion Pro tool with the blue liquid, and it developed bubbles and wasn't accurate.

[Kelly E]

I have a DigiSync electronic manometer with a built in tach. Mine is the four channel model and is very accurate and comes with connectors. It uses the vacuum pulses to determine RPM's. It doesn't need any restricters and just needs to stay above the carbs. On my V4 Sabre it is really easy to hook up but I haven't used it on an inline 4 yet, the 400F went home and my 550 isn't done yet. It is minor surgery to hook up to the Concours.