Carb tune: (Cheap vacuume gauge set of 4<--ebay)

[bexabarr]

I just found this on ebay... maybe it will work to make a cheap vacuume sync tool. I've speant too much money on my bike in the past week, or else I would seriously consider it (in inches of mercury too!). Let me know if someone actually tries or have tried it and how it turned/s out. Good luck

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=8050751786&fromMakeTrack=true

[bexabarr]

I always remember stuff after I post lol... check shipping b4 you buy, if you buy... it's not outrageous but it does bring the price up a bit... luck out there.

[bexabarr]

Here I go again... I was actually looking to make this

http://www.xs11.com/forum/showthread.php?threadid=986

I got this off another topic in the forum... does anyone know why the 'plenum' has to be so big? Thanks.

[smithbm]

Here I go again... I was actually looking to make this

http://www.xs11.com/forum/showthread.php?threadid=986

I got this off another topic in the forum... does anyone know why the 'plenum' has to be so big? Thanks.

It's supposed to provide an expansion volume so that fluctuations in pressure won't cause the needle on the gauge to bounce around as much. I haven't yet been able to find gauges cheap enough to warrant building one of these synch tools.

[Clone]

I think I could even make that sync guage, I like it better than buying a $100 Carbtune.
Couldn't you use any vacuum guage from an autoparts store?

[Nessism]

I tried to use some regular vacuum gauges and the needle does indeed bounce around ALOT. After seeing that link I'm going to try a plentum of some kind.

A few years ago I made my own carb sync tool using some mercurcy I bought and some hollow peto tubes. I drilled holes in the lid of a small medicine bottle and stuck the tubes though into the mercury. Some clear vinyl tubing on the ends of the tubes and instant sync tool. Worked great. The only trick is finding the mercury and tubes, shouldn't be too hard if you live near a big city.

Hope this helps someone.

Ed

[smithbm]

I just did a quick search and found this.

http://www.indysuperbike.com/custome...oductid=112066

[smithbm]

And this.
http://www.indysuperbike.com/custome...67&cat=&page=1

The deluxe model is $68, but the economy model is $26. As stated previously, I think the economy model will pay for itself in free beer.

[Sprockets]

Where do the hoses fit on?

I'm trying to figure out where do the hoses fit on the carbs. Do I have to drill a hole on each of the rubber intake manifold? I had to change the intake manifolds (the old ones where cracked due age) and the new ones (from an Argentinian spare parts shop) does not have any pipe to fit a hose or something like it. (I don't remember if the old ones had it, because the mechanic replaced them and trashed the old ones)
The bike is a Suzuki GS 550, 80' (carbs with diaphragm). Where are the "vacuum ports" every tutorial mentions? Any Pic?

[bexabarr]

Aqui tienes... che boludo

I took these photos a while back to show my worn o-rings... you can see where the vacuum screws go (more or less).



If you need a better pic I suppose I could take one of the one on my bike tomorrow or something.

[bexabarr]

I'm not going to spend $60 to buy a carbtune... well not yet at least

http://www.plumbersurplus.com/ProductDetail.aspx?Prod=12440&Cat=926

Would this work? what is KPA? it's prob too sensitive

If I keep looking I'm sure I'll find vacuume gauge that is cheap and works fine...

[smithbm]

I'm not going to spend $60 to buy a carbtune... well not yet at least

http://www.plumbersurplus.com/ProductDetail.aspx?Prod=12440&Cat=926

Would this work? what is KPA? it's prob too sensitive

If I keep looking I'm sure I'll find vacuume gauge that is cheap and works fine...

I don't think the picture of that gauge matches the description. There isn't any vacuum measurement. IMHO for it to be usable, it should be a liquid filled gauge. It must have vacuum measurements (preferably 0-30 inHg, 0-76 cmHg, or 14.7-0 psia). It may or may not have both vacuum and pressure measurements, however dual purpose gauges are way more expensive. You can get by with only one gauge if necessary but I think it would be a major PITA to keep switching back and forth between carbs (each time you adjust one carb, the vacuum at the other carbs changes). Besides, the economy sync tool is only $26.

http://www.indysuperbike.com/custome...67&cat=&page=1

You'll be pretty close to that number even if you buy some economy gauges for $4.00 each.

Gauges x 4 = $16.00
3" PVC Plenum = $5.00
Vacuum hose = $1.00
Hose barbs x 2 = $1.00
Carb fittings x 4 = $5.00
Your time constructing the tool and fiddling around trying to get it to sync your carbs = $(insert hourly wage x 10 hours)

If you do take this project on (as I probably will) do it for fun, because you probably won't save any money. As always, this is just my opinion and I will be more than happy to help you out along the way in any way I can. 8-)

BTW kPa = kilopascals (just another unit of pressure)

[bexabarr]

Yeah I think I might take on this project... but I would do it with only one gauge (like the one in the first link). I have looked around for the 4 valves (used in fish tanks), a set of 4 (copper ones) only costs a few bucks. I think I can find a gauge for under $10. The hoses and the pvc pipe I should have lying around the garage. I also have some natural gas fittings that I could screw into the pipe. As for the carb fittings, we'll see what I come up with. But you are right, with the work (not to bad at all) and the money that you put into it the economy carb sync is the way to go... but like you also said, this should be a fun little project (specially if it works ).

[smithbm]

Since we are going with a true "junkyard wars" carb sync tool, you may be able to make the adaptors by drilling holes through the centers of some 5 mm bolts (with the proper thread pitch). You should be able to pick some up at a hardware store (a real one, not Lowes or H.D.) for less than a buck. I would get them at least 30 mm long so that you can cut off the heads and still have enough length to attach the vacuum hoses to. This will be extremely difficult if you don't have access to a drill press.

[Macmatic]

Last year y'all bought enough intake boot o-rings for me to buy a real CarbTune II (Which if you're in the NE Atlanta area you can come by and use most any time). Reading over this thread and looking at the links to the plenum jobbie made me remember setting up the carbtune....

Instead of a plenum to smooth out the fluctuations the CT II uses a piece of very small ID hose in each line near the carb end. As I remember each line is about a yard long and you put the damper 6" from thecarb end. The damper was a piece of clear hose with about a 1mm ID but very thick walls in comparison so it would fit inside the larger tube. Works like a charm and I don't see right off why it wouldn't work with guages too...might be whole lot simpler than the plenum idea.

I'm in NY and the CarbTune is in Atlanta right now but I can look for a pic or describe it better if anyone is interested.

/\/\ac