Carb Sync Tool Info Needed

[MrOzz]

OK after much reading on the forums for carb sync tools what have we all found out?

I am planning on building my own Carb sync tool, but need some info from you that have one.

Need something to do this winter after stripping the bike, prepping for paint, meeting with the graphics guy, resembling the bike, working on the engine...

So here it goes,

Mercury the most accurate?

Non-toxic manometer fluid?

ATF?

I was thinking of building one with mercury, non-toxic manometer fluid, or ATF, I have all three.

What I need is the length and aprox id of the tubes of each of the the ones that go to the carbs. Also need the sight window size on the mercury filled one (Morgan Carb tune, mercury filled?). A non-toxic one (like the SyncPro). ATF I dont need, I read the forum.

Once I have that info I will build them and post what I came up with.


Thanks all for the help.

Ozz

I hope this makes sense been a long day for me...

[XSPastor]

The Morgan Carbtune is the best non-fluid sync tool I've used. Highly recommended. About 114 bucks and worth every penny.


Morgan Carbtune Website

[bikerphil]

mercury sticks

I just checked my Motion Pro carb sticks that I bought about 5 years ago ($50), and here are the dimensions of the clear rigid plastic tubes...

Length: 23"
O.D: 13/64"
I.D: 1/16"

I wouldn't recommend these to anyone. The heat from the engine makes the tubes brittle and they crack. The sticks I think are more accurate than the gauges. I have good results with the cheapo JW gauges, ain't tuning a Ferrari.

[tarzan]

I second the Morgan Carbtune.Mine works great.The price is a small sacrifice for ease of use and storage.JMHO

[egsols]

Haven't tred the Morgan but wouldn't mind. I built my own out of 4 vaccuum gauges.

I got the gauges for $6.99 each. Mounted them on a strip of aluminum so they sit on the bars held by each mirror. I couldn't seem to get the pulsing out until I went out and bought four mini c clamps. They all seem to work fine but I wonder how accurate they are compared to the Morgans.

I did test all four gauges on one carb to make sure they read the same but there is no way, that I know of, to calibrate them if they ever go off.

Having four gauges does make for a fast sync though, used to use one gauge with an aquarium manifold.

[ClarkGriswald]

I got one on ebay in the little metal case.. its gauges but works really well. I like the needle vavles under the gauges, you can dial em in so they dont bounce at all yet track really nicely. Even with my lamo compression on #s 1,2,3 last time I sync'd I was pulling 20 inches of vac at idle which is very good for any type of engine.. (on jeeps if you can get a steady 20 doin the lean drop method of tuning your jamming..).

[ClarkGriswald]

Just re-did mine today heres a pic.



It was idling funny/chunky so hoping my compression on 1,2,3, might have risen I checked it. Sync was off so something changed. In that pic you see the bike idling after I was done syncing.

Unfortunatly right after that, a compression test revealed that 1,2,3 which had been coming up have started going back down. Last 2 times Ive checked it its gotten worse.. OH well..

[fredintoon]

Denser is worser.

Hi Ozz,
Mercury has a density of ~13 vs water's 1 and ATF (or any other oil's) ~0.8.
So any pressure difference that you see on a manometer will be 13 times as large on a water filled U-tube as it is on a Mercury filled U-tube. Mercury thus gives you the least accurate reading. (Or more properly, the accuracy is the same but the Mercury U-tube is 13 times as difficult to read) An ATF (or I'd use a brightly coloured 2-stroke self-mixing oil) filled U-tube is even more accurate plus a little bit of oil sucked into your engine won't bother it much. Of course, the water or ATF filled U-tube needs to be WAY taller.

[MrOzz]

If I am correct, the amount of vacuum does not really matter as long as all four carbs are the same? Are the Morgan carb sticks mercury filled? Also what are the dimensions of the sight glasses that you take the readings from on the Morgans?

Thanks for all your help so far.

Ozz

[XSPastor]

The Morgan Carbtune uses no fluid of any kind. it's stainless steel slugs in clear tubes mounted in a housing. The higher the vacuum the higher it sucks the slug in the tube. very cool. Just click on the link in my previous post for more info.

[fredintoon]

Morgans

Hi Tim,
so that's how they work, neat.
If I wasn't too cheap to go and buy a gauge, that's the one I'd get. Stainless ain't toxic if you drop & break the thing and as stainless is only 60% the density of Mercury the instrument is 60% easier to read. But MrOzz wants to build his own so it's braving the hazards of Mercury vs the inconvenience of a 6 foot tall oil-filled manometer for him.

[MrOzz]

Interesting, I thought the Morgan was mercury filled. Thats what I get for thinking, lol.

So if I use stainless steel slugs in 4 tubes that would work, but I have to get the weights exact. Hmmmmm. Thinking aloud here..... 4 of the same drill bits, or metal pins. Then would have to be tight enough in the tube to keep a vaccum but free enough to move.


Ok looks like the easiest/safest would be the 2 cycle oil in the tubes....

I dont want to spend a ton on gauges and I feel the Morgan / oil filled ones would a little more accurate, not as much flutter and getting 4 gauges to be spec to each other.


So much for building a better mouse trap....


Bikerphil - Thanks for the info on the Motion Pro carb sticks.


Tim - Thanks for the info on the Morgan Carb Sticks. I would get them but I have to spend the money other places for the bike.


Fred - Thanks for the science. How tall is yours with the 2 cycle oil and what diameter tubing did you use?


Egsols, ClarkGrizzwald - Thanks for the info on the gauges.


I think I will make a slug type after the oil filled one to try it out.

[fredintoon]

Hi Ozz,
3/16" bore aquarium tube strapped to a meterstick (~3" longer than a yardstick)
The next one will be taller, there's a real risk of the stroker oil getting sucked into the carbs with this one if you start with the balance too far off.

[AlanB]

Hi Guys,

Early Morgans ARE mercury; they moved to "dry" gauges when the goverment over here (G.B.) started to clamp down on "dangerous Substances"

For anyone who uses dial-type gauges, it is worth checking 'em every time they are used; Set the bike idling, them pop the cap off of the nearest inlet boot........... Plug number one gauge on, and note the reading, then try gauge two, and three, then four.

All are reading the SAME vacuum, so all should read EXACTLY the same.............. I bet they don't......

It does not mean that your gauges are useless, just that they need a correction applied. Figure out what it is, mark it on the gauge, and synch/balance properly!

AlanB

[Axel]

Quick and easy

Morgan rocks in combo with Gunson colortune