home made sync gauge

[freak_leg]

After a little hunting this is the best deal I've found...
http://www.amazon.com/EMGO-VACCM-SYN...0819970&sr=8-2

I think I might just go this way, a time comes when its worth the extra $20 so save the head ache... And this way SWMBO wont look at me like a mad scientist when i'm in the garage with a huge length of tube and a bottle of trans oil...

[Yahman]

Bingo!!! Give the man a prize.

I like the concept of the design. The cross tube allows for oil or water instead of Hg. If you didn't have that, the tubes would have to be tall.

That's the theory, and it works to some extent. There is a small restrictor in there that I added for dampening. There's just a slight amount of bounce to the fluid in the tubes.

Larry

[DGXSER]

You can buy a vacuum gage at harbor freight, or four of them if you go that route.

[WMarshy]

Well, a few of you guys keep talkin about vac gages so...lets see one. Where can ya get one and how much are they?

[skids]

I like the concept of the design. The cross tube allows for oil or water instead of Hg. If you didn't have that, the tubes would have to be tall.

[vanhump]

I have found that it is hard to beat a good set of vacum guages hung on a bungee cord between the handlebars.

[daveyg]

Dang I need to get off my arse and make one of these ideas up. The 11 is still chillin in the shed and the 650s both need a sync to keep puttering along. Thanks for the link and pics gareth.

[gareth]

I use a combination of the simple and the slightly more complicated. I get an initial sych from carbs 1+2 and then 3+4, and then balance the pairs with a sych from 1 to 4. I do this with the single tube ATF manometer, which is nothing more than about 24 feet of pvc tubing with a couple of rubber taps on each end to attach to the sync ports. Its long, a bit unweildy, but its super accurate. The individual pulses from the engine cancel one another out and there is very little jumpiness when reading the level. Only if the sych is WAY out do I have to keep an eye on the ATF level in the tubes, which is the benefit of the 24' super-long setup. If I am feeling particularly picky, I can then hook up the four tube manometer, knowing that the sych is now so close that I am unlikely to pull fluid into the cylinders when I do a final adjustment.
The four tube manometer was way too sensitive to changes in sych to be used for initial setup. I made the 4-tube when I first started working on the bike and played around with restrictors for ages. I could never get it right and was always concerned that slight changes in the restrictors that I had put in the tubes was causing inaccuracies. I stopped using it for the initial sych and used the "big loop" to make things simpler at the start. There are no restrictors in the 4-tube either. I hardly ever hook up the 4-tube anymore. Big Single Loop does the job..

http://picasaweb.google.com/agfitz/SynchTool?feat=directlink

[RS Thornton]

One gauge works fine

The last thing you do is open up each valve in the gang valve one by one, and make sure all 4 vac levels are within tolerance.

I use a needle valve in the line in front of the guage to supress the bounce in the needle. You start with the valve closed and then slowly crack it open until needle starts to bounce, and leave it there. The whole assy shown in the pic is pretty easy to put together, is easy to store and can be hung off the bars.

The ATF system seems a bit bulky to me.

Scott

[TomRodgers]

oh boy.....

[fredintoon]

Come on now Ivan, you can't just take what I said and boil it down to something so simple. - - -

Hi proj,
it's sometimes difficult for the brilliant and gifted to realize that some list members are only of average intelligence.
Ivan has obviously overcome that difficulty as he was writing for that audience.

[81xsproject]

I just use 4 pieces of vinyl tubing connected at the bottom. its like a 4 way spirit level. Used ATF. Its almost too sensitive. No restrictions. Just be quick on the kill switch if they synch is way out.

Come on now Ivan, you can't just take what I said and boil it down to something so simple. It takes all the mystery and wonder out of the whole sync experience. I mean it's just not scary when you don't use words like "hydro-lock" and "IMPORTANT", or phrases like "KILL THE MOTOR" and "shooting up the tube."

[fredintoon]

- - - - Would using much thicker gear oil make the rig smaller since it would take a lot more vacuum to get the oil into the engine?

Hi Tony,
sorry, no. To make a smaller unit you need to use a heavier fluid. Like Mercury which has a specific gravity of 13.5.
140 weight gear oil has just about the same specific gravity (~ 0.8) as thinner oils including ATF and kerosene so it'll suck up a tube to the same height.
What the gear oil's higher viscosity will do is slow down the rate at which it will flow through whatever restrictors there are in the system.

[freak_leg]

Hi Mr Bill,
there is another way:-
Materials:-
Duck tape.
6-foot length of (say) 2" x 1/2" stick.
Transparent jar.
Four 12-foot lengths of 3/16" clear plastic tubing.
Four flow restrictors (use surplus carb jets or aquarium tube squeezers)
Can of ATF.
Assembly:-
Put ends of tubes into the jar. (jar lid is optional but reduces the risk of spilling, poke holes in it for the tubes and for filling with ATF)
Tape the jar to the bottom of the stick and run the tubes up to the top, tape them top & bottom.
Shove the flow restrictors an inch or so into the open ends of the tubes if you are using old jets or onto the outsides if you are using aquarium clamps.
Keep the riggins upright at all times.
Pour the jar 3/4 full of ATF.
Methodology:-
Remove the 4 vacuum caps from the carb manifolds.
Prop the riggins next to the bike.
Put a tube end on each manifold vacuum tap.
Note which tube goes where.
Start the motor.
You will see ATF being sucked up each tube.
The tube with the highest level is being sucked on the hardest.
Adjust the carbs until the levels are the same.
Notes:-
Accuracy:- As ATF is ~13 times less dense than Mercury the height differential between fluid columns will be 13 times as great and so far easier to see.
Why ATF?:-
ATF is readily available, brightly coloured and won't harm the engine if it gets sucked in.
Drawbacks:-
The riggins is 6 feet tall and full of ATF. Compared to a set of commercial carb sticks or vacuum gauges it has storage and movability issues.

So just to make sure i get what your saying here (hampster is a bit slow sometimes, gotta double check his work) More or less 4 tubes running up a board into a jar of oil hooked to the manifold nipples with some restriction and get the vacuum set so that all 4 tubes have the same amount of oil in them? Would using much thicker gear oil make the rig smaller since it would take a lot more vacuum to get the oil into the engine?

[Ivan]

I just use 4 pieces of vinyl tubing connected at the bottom. its like a 4 way spirit level. Used ATF. Its almost too sensitive. No restrictions. Just be quick on the kill switch if they synch is way out.