Carbmate zeroing question

[philwarner]

I used my new Carbmate TS-110 to balance the 96 Cali's carbs today and it worked well, but I had a question.    The instructions say to turn the zero adjust knob until the center LED lights up to zero the unit.  The LED left of center was lit so I turned the knob until the center one lit, but turning it beyond the point where the center LED lights does not cause the light to the right of center to come on.  So should you turn the knob until the center led JUST lights and leave it there?  Does it change the balance point if it is turned beyond the point where the center LED first lights?  I sent this question to the TechMate web site but have not yet heard back.  Any input from Carbmate users?

I was surprised at how delicate the cable adjustments are to balance the carbs at higher RPMs and I suspect that the balance should be checked often to keep them balanced.  The Carbmate makes this pretty easy and the engine was running much better at idle and at higher RPMs after a few idle screw and cable tweaks.  I could not have done this by ear at all.  I am tempted to hook up my home made manometer to see how well the Carbmate did, but I'd bet they are really close using this gadget by the way  it is running now, and it is way easier to use.

The instructions that came with my unit were a little smeared and while looking for the instructions on line I found a web site that sells the Carbmate TS-110 for $49;  I had looked at Amazon, eBay, and other sites that were selling it for $130 and more, I paid $120 for it plus shipping from a Guzzi supplier.but did not see this site until after I'd bought it. Darn!

Another surprise was how much air the breather hose passes.  Mine was disconnected from the air box when a PO removed the box and installed individual filters, and I had routed the hose from the frame to beside the right carb where I could add a little breather filter I ordered when it comes in.  That hose was puffing a lot of air with the engine running while I was adjusting the carb balance - much more than I expected.

[fotoguzzi]

Sounds like something wrong with the tool, seems like the right side should light up just like the left about the same distances of turn as the left side. Did it ever come on while tuning?

[philwarner]

Sounds like something wrong with the tool, seems like the right side should light up just like the left about the same distances of turn as the left side. Did it ever come on while tuning?

Yes, both sides lit at points in adjusting the idle and especially in adjusting the cables.  I got it to where it remained centered at idle and up to 5000 RPM with a few flickers left or right as it backed off but mostly centered at the lowest sensitivity setting.

Maybe I need to try zeroing again and testing again?

(Still kicking myself for having spent an extra $75 on this gadget, but it is pretty cool)

[Kiwi_Roy]

I used my new Carbmate TS-110 to balance the 96 Cali's carbs today and it worked well, but I had a question.    The instructions say to turn the zero adjust knob until the center LED lights up to zero the unit.  The LED left of center was lit so I turned the knob until the center one lit, but turning it beyond the point where the center LED lights does not cause the light to the right of center to come on.  So should you turn the knob until the center led JUST lights and leave it there?  Does it change the balance point if it is turned beyond the point where the center LED first lights?  I sent this question to the TechMate web site but have not yet heard back.  Any input from Carbmate users?

I was surprised at how delicate the cable adjustments are to balance the carbs at higher RPMs and I suspect that the balance should be checked often to keep them balanced.  The Carbmate makes this pretty easy and the engine was running much better at idle and at higher RPMs after a few idle screw and cable tweaks.  I could not have done this by ear at all.  I am tempted to hook up my home made manometer to see how well the Carbmate did, but I'd bet they are really close using this gadget by the way  it is running now, and it is way easier to use.

The instructions that came with my unit were a little smeared and while looking for the instructions on line I found a web site that sells the Carbmate TS-110 for $49;  I had looked at Amazon, eBay, and other sites that were selling it for $130 and more, I paid $120 for it plus shipping from a Guzzi supplier.but did not see this site until after I'd bought it. Darn!

Another surprise was how much air the breather hose passes.  Mine was disconnected from the air box when a PO removed the box and installed individual filters, and I had routed the hose from the frame to beside the right carb where I could add a little breather filter I ordered when it comes in.  That hose was puffing a lot of air with the engine running while I was adjusting the carb balance - much more than I expected.

It may not be for sure that the zero knob works the same on both sides of zero it may be just tweaking the measurement one way. If I had a schematic I could tell for sure.
As to the price, I googled it  here its CAD $180, I don't think that's excessive, it's already paid for itself by not having to take your bike into a shop, besides the $49 unit may have been a knockoff or a used unit. You will enjoy using it from here on. I would think most professional mechanics would use something like that.
The nice thing about an electronic unit as you say it's easier to use and you can check it under load.

[philwarner]

It may not be for sure that the zero knob works the same on both sides of zero it may be just tweaking the measurement one way. If I had a schematic I could tell for sure.
As to the price, I googled it  here its CAD $180, I don't think that's excessive, it's already paid for itself by not having to take your bike into a shop, besides the $49 unit may have been a knockoff or a used unit. You will enjoy using it from here on. I would think most professional mechanics would use something like that.
The nice thing about an electronic unit as you say it's easier to use and you can check it under load.

the $49 unit looks the same on their web site, but then photos are easily copied and the Chinese are clever folks.  The "zero" point was just past mid point of the knob's range, so I expected to see a "gone too far" point and to find a mid point between the two sides.  I guess the safest is to set it at the "just changed to middle light" point and no further.  I did see the middle light change brightness as I was doing adjustments, but there was no mention of this in the instructions.  I think the "off center" LEDs sometimes blinked too, especially the amber 2nd or red 3rd LEDs. Guess I need a little more practice to be sure.  I'll do the Triumph next.

I belong to a British car club, and there are a lot of little British 4 bangers with two SU carbs; perhaps there is a way to use the Carbmate on them too.

[apex1397]

Tie both vac. lines together with a T junction and hook the extra hose to the vac. port. Zero the indicator while both hoses are reading the same pressure.

[philwarner]

Tie both vac. lines together with a T junction and hook the extra hose to the vac. port. Zero the indicator while both hoses are reading the same pressure.

Interesting idea.  The instructions say to zero it before the vac lines are hooked up, but that could be an interesting test.  They also say not to cut the hoses so apparently they feel unequal length of hose might affect the balance or the Carbmate's perception of balance.

[Kiwi_Roy]

Tie both vac. lines together with a T junction and hook the extra hose to the vac. port. Zero the indicator while both hoses are reading the same pressure.

As an instrument tech that makes sense, it should be just the same open to atmosphere but under vacuum is better, thats where it's used and that's where you need it to read correctly.
I expect you will find the balance is no different at atmospheric or under vacuum so from then on just do it the easy way.

[philwarner]

As an instrument tech that makes sense, it should be just the same open to atmosphere but under vacuum is better, thats where it's used and that's where you need it to read correctly.
I expect you will find the balance is no different at atmospheric or under vacuum so from then on just do it the easy way.

Perhaps T the lines and pull a vacuum with a Miti-Vac?  I wonder if there is a vacuum level that might do damage to the unit.

[philwarner]

I received this in an email from TecMate:

Hi Phil
Our office re-opens on Jan 2nd. How-ever, let me see if I can assist.
You are ZERO’ing correctly, but just to be sure -
To ZERO the CarbMate it should not be connected to carburetors, only to power, in other words, connect to 12V power, ZERO the CarbMate, then connect the tubes to the carburetors to be synchronized.
If this is what you have done, it is unusual for the LED to the right to not also turn if your are turning ‘past’ ZERO center, but as long as you can ZERO without either the LED left or right of  center turning on, you’re OK. If this changes, please let us know.
Sincerely
Martin Human


UPDATE:  I picked up a power cord for the Carbmate with a Cigar lighter plug so I could use the power plug I installed for my GPS, and I made sure the Carbmate sensitivity was set to the most sensitive for zeroing, and this time the right and left amber and red LEDs did light up when the zero knob was turned left and right from center, and the green center LED got brighter when in the center "zeroed" position.  I guess it is working as it was intended, so I may revisit the balancing I did before, but I promised myself a new year's day ride when it warms up today.  Maybe when I get back.