brain teaser (carbs? ignition?)

[JerseyJon]

Inspired by all the carb work going on here, I decided that my carbs, which ran pretty well, needed syncing. The bike was idling unpredictably -- sometimes as low as 700, and sometimes as high as 2500. Plus, I had to nearly kill the battery every time I wanted to start it from cold.

So I broke out the new motion pro carb sticks, turned the tank around, and started to gigure out which carb is used as the standard to sync to. I pulled off some hoses and caps, and realized that I needed to calibrate the tool. So I put the caps back on, and, of course, the first thing that happened was that I sucked a bunch of blue liquid into number 3. Because I was out of blue liquid, I figured, why don't I just try to get the idle speed right. So I messed around with the idle speed knob and got that pretty well messed up so that I couldn't start the bike any more. So I hooked the battery up to a charger, and took a nap.

When I woke up, I put the tank back on, started her up, and she ran. But now she skips and backfires on deceleration, and doesn't seem to have quite as much power as she did before I laid my skillful hands on her.

Two side notes: 1) When the engine was cold, I started to remove the cam cover thinking I would adjust the valves. Yes, I have extra shims, if folks want some for trade. I also pulled the plugs and they looked good. maybe a little brown, but clean. The rubber cap on plug number 4 was old and cracked, and the round rubber bushing that goes around it broke. I taped it up with electrical tape as best I could. I never got to the valves for lack of time.

What can I do to get the bike back to where it was? Could this NOT be a carb issue and have to do with my ignition wires? Any help is greatly appreciated.

[natemoen]

You need to do a good sync and idle adjustment

No more sucking blue liquid for you!

[JerseyJon]

You need to do a good sync and idle adjustment

No more sucking blue liquid for you!

I was afraid you'd say that. It looks so easy when you read about it on the threads. And I was hoping you guys would say, just put in new ignition wires, because I know how to do that. So here's a question: When you calibrate the gauges, do you take the caps off of all 4 carbs? I mean, the blue liquid got sucked in there really quickly. And what do you do to prevent the liquid from getting sucked into the carbs?

[JerseyJon]

and one more question

Generally, when you pull the cam cover, can you preserve the gasket? Or should I not start that job until I have a new gasket handy?

[natemoen]

There is no calibration needed for the sticks, it works on how well you engine sucks against gravity and gravity doesn't change. Calibrations are only for multi gauge setups.

Valve cover gasket is a 50/50 thing. You might get it off whole, you might not...

[JerseyJon]

There is no calibration needed for the sticks, it works on how well you engine sucks against gravity and gravity doesn't change. Calibrations are only for multi gauge setups.

Very interesting. The motion pro instructions say you MUST calibrate the thing, on penalty of death. They give you a "calibration manifold", which hooks up all four hoses on the tool to one carb to one carb. Theoretically, the vacuum in each tube should be equal, and then you can adjust the height of the blue fluid column with these little screws on the tool. That made sense. Of course, I never got that far, but I did notice that before my mighty SG sucked down the blue goo, the columns were not quite equal.

Doesn't it make sense to calibrate? I mean, if it's not calibrated, then mightn't you be de-syncing the carbs when you get the columns level?

[natemoen]

hmmmmm i guess i could be wrong but i dont know what there is to calibrate in a liquid base setup. Unless there is some sort of orifice somewhere in them that you are equalizing somehow.

[JerseyJon]

Nate,

I think there is just such an orifIce, at least on this particular model.

[motoman]

Jersey, bettin' your not gonna like MotionPro's "new" liquid set-up. Least that's what I've been told by several bike wrenches who've used them. Let us know here whatcha' think when the scoot quites drinkin' it all up.

[ddragon63]

You need to do a good sync and idle adjustment

No more sucking blue liquid for you!

this is why I bought the multi gauge style. pretty easy to calibrate and no fluid to suck

[natemoen]

this is why I bought the multi gauge style. pretty easy to calibrate and no fluid to suck

Yeah, that's why I went with the carbtune. No calibration, all weight and gravity.

[JerseyJon]

Well, in the meantime, I went and bought the stuff for the homemade sync tool -- tubing, vacuum gauge from hf, fish tank manifold,some PVC. Will report on how that works.

[GLoweVA]

I do beilieve that the 'calibration' needed on the sticks is to make sure all 4 levels are at the same height when you start. If not you can add more liquid to the low ones to even them all out, or maybe balance them all out on the bottom.
If all 4 aren't at the same level when you start how are you supposed to get them level with the bike running drawing different amounts of vac on each carb.

Just my 2 cents

[JerseyJon]

I do beilieve that the 'calibration' needed on the sticks is to make sure all 4 levels are at the same height when you start. If not you can add more liquid to the low ones to even them all out, or maybe balance them all out on the bottom.
If all 4 aren't at the same level when you start how are you supposed to get them level with the bike running drawing different amounts of vac on each carb.

I think you're right. And if they're off before you start, and you make them level once you hook them up to the carbs, then you're actually de-synching the carbs. So I'm interested to try the homemade one, since there's no fluid to suck, and unlike the multiple gauge tool, there's only one vacuum guage, so you really don't have to calibrate. The multi-gauge tool assumes consistency among the four gauges. The homemade fishtank gauge just uses one vacuum gauge.

[GLoweVA]

Yeah, it is simple. I made one myself last year. Even though it takes a little bit more time having to 'switch' between cylinders by opening and shutting the 'fish tank' valves, you're right about the gauge reading the same.

Like others have said, make sure you've got some kind of air moving across that engine, it will get hot. (fan, stiff breeze, etc.)

I got my gauge from harbor frieght and the 4 way valve from a pet supply store and the PVC was already 'precut' at home depot with the end caps right there in the same isle. I also got the barbed threaded inserts to screw into the 'chamber/tube' at the depot too. Make sure your tubing it not too flimsy. The suction of the carbs can try to collapse them. (oh and the heat might try to melt them too, so don't let them get too close to the head)

Cost me less than $20 for it all. (The gauge was the most at about $10)