Manometer idea for carb sync's

kx_125_pilot wrote:

ok, so lets say i wanted to sync the carbs on my 82 kz440....how would i go about making one of these meters and conecting it up to my carbs?? and how do i adjust my carbs?

Just like this one steell posted a pic of, because you have a twin
link here www.powerchutes.com/manometer.asp

If you are syncing two cylinders at a time, do you adjust the low cylinder or the higher cylinder, or does it matter?

I think the "Ideal" is 12-16cm of mercury so, adjust as required to get both within that range then adjust either one to match the other.

OKC_Kent wrote:

If you are syncing two cylinders at a time, do you adjust the low cylinder or the higher cylinder, or does it matter?

I always adjust the one that's easiest.

I don't know if it matters much, but I thought I read somewhere you want to have the highest vacuum you can get..

OKC_Kent wrote:

I don't know if it matters much, but I thought I read somewhere you want to have the highest vacuum you can get..

Maybe, but that is not the purpose here. If you increase the vacuum on one, the idle will drop so you will adjust the idle higher which will then drop the vacuum on all cylinders. It's just a balancing act, you cannot determine what the final vacuum will be, that will be determined by where you set the idle speed.

You don't need any numbers on your gauge because you really don't care what the value is, as long as the cylinders are the same.

OKC_Kent wrote:

If you are syncing two cylinders at a time, do you adjust the low cylinder or the higher cylinder, or does it matter?

Per the factory service manual. "Normal vacuum guage reading is 19 ~ 24 cm Hg, and the difference between any two cylinders should be less than 2 cm Hg."

I recall that on my SR the reading on the Motion Pro Stix came in right around 22 cm Hg at a nice low idle. It took some trial and error with the locknuts, but I was able to get them well within the 2 cm specified difference. In fact when I started, the right two were 2 cm higher than the left two with 1 & 2 and 3 & 4 being even after a bench sync.

Use the idle speed knob to get the Hg in the desired range. As the engine revs higher there will be less vacuum and vise versa.

- Nate >>

It's good that they give you a number, but that is really only to find out the condition of your engine versus stock.

Since your idle speed makes all the difference, you really won't know if one cylinder is too high or if one cylinder is too low. Soon as you increase your idle, the high one will become normal and the normal one will become the low one.

Don't make it hard on yourself. Adjust the easiest one to get to, or if you want, try to adjust them such that they all end up near the middle of their adjustment range. You are just adjusting the throttle which is the same thing the idle-speed adjuster does. The idle-speed adjuster just does all 4 at once.

Post edited by: loudhvx, at: 2006/05/05 11:12

you can make your own synchroniser using 4 0-30 vacuum gauges, 4 elbows and 4 flow control type dampners. like this one i made below. its crude but it works great..steve

fixer5000 wrote:

you can make your own synchroniser using 4 0-30 vacuum gauges, 4 elbows and 4 flow control type dampners. like this one i made below. its crude but it works great..steve

Where did you get the flow control type dampers? All the small valves I can find are kinda pricey. I'm going to buy four gages and use a simple screw and washer to squeeze down the hose and act as a damper, but I'd rather use an inexpensive valve.

OKC_Kent wrote:

fixer5000 wrote:

you can make your own synchroniser using 4 0-30 vacuum gauges, 4 elbows and 4 flow control type dampners. like this one i made below. its crude but it works great..steve

Where did you get the flow control type dampers? All the small valves I can find are kinda pricey. I'm going to buy four gages and use a simple screw and washer to squeeze down the hose and act as a damper, but I'd rather use an inexpensive valve.

yes they are pricey but youll only buy them once...why not get good ones. the ones im using are smc fittings. they have similar types at mcmaster car. another thought is a multi setup for an aquarium pump. they do the same thing. you just use them to calm the needles on the gauges a bit...steve

fixer5000 wrote:

you can make your own synchroniser using 4 0-30 vacuum gauges, 4 elbows and 4 flow control type dampners. like this one i made below. its crude but it works great..steve

How much did this setup cost you?