nath981

With the OEM CCT in there, the chain had about 1/8 slack between the sprockets at TDC, I was able to duplicate that using the method described in the previous post.

Yeah this mod seems to be a good set up. Thanks to Calitoz for the description and pics and Tweety for explaining how and why it works and the simple bolt in the OEM CCT doesn't.

I don't have a drill press to center-drill the top of the worm gear(which has a slit) so that the adjusting bolt can be secured, so i used a dremel with a cone shaped stone to start a centered hole, then hit it with a 5/16 drill. The result is a cone shaped divot. Then ground the end of the adjuster bolt slightly and it fit right in the divot.

8541Hawk

Well let me ask a couple of question regarding the train of thought that sync'ing means getting both butterflies to open at the exact same time.

First, have you ever done a compression test? If so were the numbers between the cylinders exactly the same? It can happen but is actually rather rare for that to happen. So if there is a difference in compression, wouldn't there also be the same difference when the piston tries to fill the cylinder (or the amount of vacuum created)

Then, with different length velocity stacks do both cylinders have the same flow at idle?

So if these things are true, wouldn't you get a different vacuum reading on each cylinder if the butterflies were set exactly the same?

Wouldn't you also be de-sync'ing the carbs as soon as you hooked up a vacuum gauge and balanced the vacuum each carb is seeing?

Then the comments about the slides not being important. What is important, how the bike runs at below 3k and the throttle pretty much closed or 3k and above with the throttle open?

If you picked #2 then you would be more concerned that both slides see an equal vacuum signal so that they can open in sync.

So you can say what you want but I will stand by statement that what you are doing is making sure you have a equal vacuum so you get equal slide operation. The butterflies will be off, maybe not by much but still they will be at different openings, when sync'ed with a vacuum gauge.

8541Hawk

In the spirit of clarity could you please explain something?

My question is, If sync'ing means getting the butterflies set to the exact same position, how would changing the valve lash have any affect on them?

nath981

well, we may be able to answer this question once and for all. Yesterday I called local honda and other bike shops to see if I could pick up some valve shims. Negative, nada, zip, zilch, zero and f*(k you! They said they could order them of course, but i wanted to get it back together quickly so I might take advantage of a brief respite in winter weather predicted for tomorrow. My wife was looking at the shims as I called around and minutes later she comes out with a jar of used watch, hearing aid, game, and other little batteries we collected for recycling. She says what about these? I laughed and pushed them aside at first, but as i glanced at the batteries, some of them liked looked they might be at least suitable for sizing.

To my surprise, with a micrometer and batteries scattered all over the table, I was able, after an hour or so of measuring and about 3 cups of go juice, to find the exact sizes i needed. So I pulled out a couple batteries for strength testing, bagged the good ones i measured, put the rest back in the jar and headed for the garage. After placing the test batteries in a vice, I found that they seemed plenty strong enough to be used, at least temporarily, to find out if i had indeed chosen the correct sizes to yield the clearances of .007in Intake and .013in Exhaust. These are +.001, but still in spec, with the anticipation that the valves will remain in spec for a long long time, hopefully delaying the need for pulling all this **** apart any sooner than necessary.

Anyway, i put the batteries in their respective positions, and upon checking the clearances, found that my calculations were spot on at .007 and .013 for both front and rear cylinders. Wow! that felt great to get it right the first time. Well now I am psyched. I couldn't resist the urge to fire this thing up, so i put everything back together and finally got it running late last night, er maybe early this morning. haha. Wow, i think we may have something here. It purred like a kitten, smoother than I've ever heard it since i bought it 10 years ago. So, I took it for a short ride and it runs much stronger than ever and, to maybe shed some light on 8451Hawk's thesis, this all without a re-sync of the carbs.

I decided that i would let these battery/shims in there for a while since i knew, or believed, that they had the necessary structural integrity(based on my vice testing) to last at least until I get some shims ordered up. Well, i wanted to do a little ride today since the weather is supposed to be the sunniest and warmest of the next couple weeks, a balmy 38F high this afternoon, and because i was anxious to do some third gear wheelies with my new super, sewing machine smooth Super Hawk mill.

So psyched to try this thing out, I go out to the garage this morning, get all my gear on, earplugs in, hit the choke and fired her up. Wow! Holy F*(k!.........the lights shining off the garage wall are almost blinding, like super LED bright, unbelievable! WTF is going on. So i pushed the horn button and it sounded like a freakin train horn echoing through the garage. Scared the living bejesus out of me and i almost dropped the bike. I put it back down on the sidestand, pulled my ear plugs to listen to my purring kitten. As I am in squatting down listening in wonderment, I am hearing a subtle ticking, maybe loose CCTs I don't know. As I continued to listen, I heard a little tocking with the ticking, like tic tic tock, tic tic tock, tock tic tock, and then a tock tock tic. I'm baffled and thinking..................... those GD batteries must be charging themselves and hyper powering my electrical system and, maybe even making this monster run like a raped ape as i noted on my short test ride last night.

Does anyone know if this is even possible?

FL02SupaHawk996

Man, I never new this was so hard to do

I got a shim kit if you need it just send me a PM...Rick C.

7moore7

Dude, three things...

1) Is heat going to be a problem with this? As in, will the batteries swell? The cylindrical shape of the batteries seems to be strong enough to support the system tho...

2) If they fail, what are the consequences? I think it may be bad, which the worse the consequences are, the more I like to get something right.

3) If that magic power you've gained from adding batteries to your system actually works, then holy crap start working on patent drawings b/c that **** is awesome! It has all the ingredients in the system that I know about electricity: Metal, moving stuff, batteries, some smart person telling you why there is no way that would work and you probably did something else for it to be like that (these are coming...)

RCVTR

I never said anything about getting the butterfies to open at exactly the same time. They will, of course because they are mechanically linked.

If everytyhing were perfectly symmetrical in the engine, there would be no adjustment necessary. Syncing the carbs sets the vacuum the same on both cylinders. it does this by setting the rear throttle plate, so that the vacuum in both cylinders is the same. Simple as that.

The slides have a very large opening, when in the fully closed position. The opening around the throttle plates is very small. The edge of the throttle plate is very near and immediately in front of the idle port in the carb venturi. This creates a high velocity across the idle port, when the throttle is closed. The velocity through the slide opening is very low at idle, because the cross-section is many times higher, with the same mass flow rate.

I'll say it again. The slides play no part in carburetion at idle.



Nath, maybe you should try A123 watch batteries. It will be like increasing the duration and lift of your cams. You'll be at stage 2, for a fraction of the cost.

8541Hawk

I never said they did. What I did say is in the process of sync'ing the carbs, you are balancing the vacuum signal. That way when you open the throttle, you will continue to have a balanced signal so the slides can open together.

Though this is getting almost silly by now. The problem I had was with the statement that sync'ing the carbs meant getting the butterflies to be set exactly the same. If it was you would mechanically set the sync between them not use a vacuum gauge.

Now if you really want to get into the theory of how the pressure differential works or vacuum in general, I could talk about that all day as that is what I actually do for a living ( well up until a couple years ago when everything took a **** around here and I started my own bike repair business) and I specialize in the operation and repair of Helium Mass Spectrometers http://en.wikipedia.org/wiki/Helium_mass_spectrometer.

I have also personally built systems with a base pressure of 1x10 E-15, so like I said I have a pretty good grasp of what vacuum is and how it works.

At this point I guess I am a bit frustrated that I have been unable to make my points clear enough for everyone to understand. So I'll try one last time to illustrate what I am saying.

There are 2 basic types of carbs on motorbikes. We'll call them mechanical & vacuum (or pressure differential) in this case to keep thing simple.

On a mechanical carb, the throttle cable hooks directly to the slide. So when you twist the throttle to 1\2 way opened (for example) the slide opens 1\2 way. The advantage to this set up is a quicker reving engine. this disadvantage is they are much more susceptible to changes in atmospheric pressure be it from a change in altitude or even a change in weather.

The reason for this is that when you abruptly open the throttle, there is a drop in pressure differential through the venturi. A way to visualize this is picture a vacuum cleaner with a hose attached. When you put your hand over most of the opening you can hear the air going by your hand at high velocity. The remove your hand, you can also hear the velocity drop to almost zero and even the motor of the vacuum slow for a fraction of a sec as it takes the bigger load.

How this relates to carbs is that when you wack the throttle open, you loose the pressure differential until the engine builds enough revs to compensate for the larger opening it is pulling through. This causes the engine to bog down momentarily. The way to alleviate this problem is an accelerator pump. This blast of fuel allows the engine to keep running smooth until it can build up enough pressure differential for the carb to function properly.

The problem with this type of carb is that if you have a change in atmospheric pressure (due to altitude change or even weather change) then the column of air moving through the venturi has a different density which requires a different accelerator pump setting. This is why these carbs are great for max power and\or racing but a pain in the *** on daily ridden machines.

You also have a selection of slides with different cut outs to also compensate for atmospheric changes but we'll just kind of leave that out right now for clarity.

Then you have CV (vacuum) carbs.
On this style of carb you have both a butterfly and a slide. In actuality the slide doesn't care what position the butterfly is in, the only thing that matters to it is the pressure differential through the venturi.

Think of it as an analog "fly by wire" set up. What happens is say you open the throttle 1\2 way, the butterfly opens telling the slide you would like 1\2 throttle. Then the slide looks at the pressure differential, as it slowly builds through the larger butterfly opening (but doesn't drop due to the slide remaining closed and only allowing flow through the cut out) the slides slowly open and there is no need for an accelerator pump as you never get the drop in pressure differential that you do with a mechanical carb .

The disadvantage to this set up is a slower reving engine. The advantage is the slides automatically compensate for atmospheric changes as they only open when you have the correct pressure differential.

Yes I have left a few minor things out but I'm trying to keep this as simple as possible.

Which leaves sync'ing the carbs.

On mechanical carbs, you measure the slide opening so that they move together (I.E. so that 1\2 throttle = the slide 1\2 way open on all the carbs) and then you tune them by adjusting the slide opening & accelerator pump.

On vacuum carbs, you hook up a gauge and balance the vacuum signal as that is what controls the slide opening. The purpose of this is the same as for the mechanical carbs, to get the slides to open together.

Hop[e this makes things a little bit clearer.

RCVTR

Ahhh - now we're speaking the same language.
I'm sure the miscommunication is largely my fault, due to rapid skimming of the words.

The only thing I would still debate is that I believe syncronizing the carbs is more about off-idle response than slide syncronization. I say this because the cross-section for airflow is very small at idle and therefore very sensitive to small changes in the throttle plate position.

By the time the slides begin to actuate, the airflow cross-sction is much larger and therefore less sensitive to very small differences in the throttle position.

Also less sensitive to small changes in the intake valve clearance