Topic: Motion Pro Syncpro Tuner or Carbtune 4?

[Magpie]

I'm wondering which carb tuner you prefer? I have an very old set of vacuum gauges and thinking of upgrading. Even using the dampers my gauges needles still bounce around a lot.

https://www.motionpro.com/product/08-0411

https://www.carbtune.com/

Thanks, Cliff.

[carnivorous chicken]

One vote for Morgan.

I know some people swear by them, but I've had issues with bubbles, etc., with the Motion Pro. No liquid in the Morgan, which also makes it easier to carry around.

[ZTatZAU]

+1 on the Morgan!

I've used gauges in the past but bought a CarbTune Pro last year when my K1's resurrection began.  I liked the steel rod concept and its simplicity with everything contained in a nice little package.  Worked great on my 750.

ZT

[Johnie]

+3 on the Morgan. I've had mine 20+ years now and it never fails me. No bouncing gauges and very reliable.

[craz1]

Well I have used both. The motion pro worked for a bit then had problems with bubbles in the fluid that were hard to get out. The carbtune worked for a while until the tubes got gummed up and the slides were sticking. I have a set of mercury gages a built but I know that is not a good option for most. So if I was going to buy a set a would be looking at a digital set like DigiSync.

https://thedigisync.com

[Deltarider]

Out of curiosity I've tested the method Common-Motors video* shows in their video. At an aquarium store I bought the 5-valve Superfish variant, instead of the 4-valve Common Motors uses as I judged, that instead of taking off that little cap all the time, a fifth valve is handier. In the basement I dived for my machined adapters, tubes and a vacuum meter. For adjusting I had made my own tool decades ago. Will post pics soon. Worked well. I had completed the job, without even having to connect a bottle with gas to the fuellines. But...  my bench sync had already been close: within 2cm Hg. Also I should add that I have synced quite some of these carbs before, so I know in what direction I have to make the small increments. For those already familiar with syncing, I can recommend the method. 
*

[Deltarider]

Nothing beats making your own tools. I looked for making the Common Motors set even more economical.
The first pic shows all tools involved. I have decided for a 5-valve aquarium air distributor (Superfish € 7,-) over the 4-valve set Common Motors offers, as I judged using that 5^th valve much easier for in between bleeding than removing that cap at the end everytime.
When I travel, most of the depicted tools are in my tankbag anyway.
Those small brass adapters I had already machined back in the 80s. The gauge and the dampener I have used for checking my bench syncs, ever since I had donated my 4 EFKA gauge set to a yacht mechanic who had helped me with my diesel engine.
Now to the adjuster. The screwdriver always travels with me because it is much easier for eventual adjusting the air screws like when I ride at high altitudes (Alpes, Pyrenies, Dolomites) than the flat blade in the standard Honda toolset. For adjusting the sync, I have modified the screwdiver a little bit. In close up you will notice I've put some tube over its stem, so it fits nicely inside the 8X9 pipe wrench, with just enough play. The 8mm side of that pipe wrench is as well for fitting the brass adapters in the manifold vacuum ports as for the 8mm locknuts of the sync adjust screws. I have machined the cross drilled hole near the 9mm side of the pipe wrench, so I can now screw a 8mm bolt in it. For the time of adjusting, that bolt is my lever to slightly tight the adjuster locknut whenever I have adjusted the vacuum by a small increment. After the job, when I'm fully satisfied with the result in total, I will tighen those locknuts just a tad further by applying a 12 mm wrench (from the standard Honda tool set) to the 9mm end. If you look closely, you'll notice I have put a piece of tube there. It's to prevent the 12 mm wrench from sliding down the stem.

[willbird]

Nothing beats making your own tools. I looked for making the Common Motors set even more economical.
The first pic shows all tools involved. I have decided for a 5-valve aquarium air distributor (Superfish € 7,-) over the 4-valve set Common Motors offers, as I judged using that 5^th valve much easier for in between bleeding than removing that cap at the end everytime.
When I travel, most of the depicted tools are in my tankbag anyway.
Those small brass adapters I had already machined back in the 80s. The gauge and the dampener I have used for checking my bench syncs, ever since I had donated my 4 EFKA gauge set to a yacht mechanic who had helped me with my diesel engine.
Now to the adjuster. The screwdriver always travels with me because it is much easier for eventual adjusting the air screws like when I ride at high altitudes (Alpes, Pyrenies, Dolomites) than the flat blade in the standard Honda toolset. For adjusting the sync, I have modified the screwdiver a little bit. In close up you will notice I've put some tube over its stem, so it fits nicely inside the 8X9 pipe wrench, with just enough play. The 8mm side of that pipe wrench is for fitting the brass adapters in the manifold vacuum ports. I have machined the cross drilled hole near the 9mm side of the pipe wrench, so I can now screw a 8mm bolt in it. For the time of adjusting, that bolt is my lever to slightly tight the adjuster locknut any time I have adjusted the vacuum by a small increment. However, after the job, when I'm fully satisfied with the result in total, I will tighent those locknuts just a tad further by using a 12 mm wrench (standard Honda tool set) to the 9mm end. If you look closely, you'll notice I have put a piece of tube there. It's to prevent the 12 mm wrench from sliding down the stem.

OK so you are just checking each carb in turn ?? Then making an adj, and again checking each carb ?? I like the idea of using MAP sensors, just need to get some and do the bits and bytes work of making them work. The setup like you show could be be used with a single MAP sensor too.

Bill

[rotortiller]

Garbage video, calibrate your gauges before use.

[willbird]

Garbage video, calibrate your gauges before use.

I did not even watch it LOL.....I agree that they should work just fine if used properly.

Bill

[Deltarider]

Garbage video, calibrate your gauges before use.

Calibration can only be checked with all four gauges on one stabil - non pulsating source.
Quite frankly, most in this here forum, are served best by having the synchronisation done by a mechanic. You can do tens of thousands of miles without a resync.
Most cases of uneven running are caused by the ignition. Multiple causes. In my experience carbs go rarely out of sync. Yet in this forum it is syncing everywhere. Also adjusting floats runs like an epidemic.   

[Deltarider]

I did not even watch it LOL....[...]
Bill

Gee, you must be a true expert, Bill.

[willbird]

I did not even watch it LOL....[...]
Bill

Gee, you must be a true expert, Bill.

Jack of all trades master of some LOL. I have a set of mercury manometers my dad made for my K2 but 50 years have not been kind to them and they are not usable any more.

Bill

[Tenn_CB400f]

I am the outlier with a TwinMax (I've used one for years on Guzzis and Ducs) and just use one cylinder as reference and do the others off it.

[BenelliSEI]

Cliff…… I’ve used my motion pro “sticks” for years. They work really well and do need to be cleaned out and reset with fluid regularly. As instructed, I calibrate them before every use. I’ve tried different stuff, but the only fluid that really works in them is the motion pro refills.

Having said all that, if I buy a new one one day, it will be the carbtune. They look good and less work.

[HondaMan]

I've stayed with the dial gages: storing the mercury-filled tube version I had resulted in eventually losing the mercury (boy, is that stuff hard to get off a hardwood floor!) when it got laid flat after a move to a house. It takes some time to decide where to set the 'debounce' needles so they act equally, but after that they have been good for the 20 times or so I've used them. They toggle about 3 increments on the indicated range when all are equal.

[M 750K6]

I used carbtune on my CB750K6. Very simple.

My only (minor) complaint is you have to cut into the 4 rubber connecting pipes  to insert a short plastic anti-flutter pipe in each. It comes with all the bits and instructions. It's simple to do. But I felt I was completing their manufacturing process for them.