five-speed concours?

[jworth]

There are some very effective home brew devices that can be used to balance your carbs.  Done properly they can eliminate the possibility of sucking fluid into your carbs.

http://faq.ninja250.org/wiki/How_do_I_synchronize_the_carburetors%3F
Look about 1/2 way down the page.  I chose another route that did away with liquids altogether. 

I'm not saying your commercial choices are bad.  I'm just saying there are frugal effective alternatives.

[julianop]

Frugal is good. I have to give all this month's pocket money to SISF, so I'm happy to throw something together myself. I keep tropical fish, so I'm fully adept with pipe and bottles.

So I'll bite: what's your fluid-free method, jworth?

[gtr1000]

Those in favor of the Carbtune http://www.zggtr.org/index.php?topic=2327.msg26753#msg26753

[julianop]

Windsor eh???

I'm a Hounslow boy - not far away from you :-)
Well Hanworth, actually, just east of Feltham. Spent many a happy hour wandering around Crane Park. Used to go in to Twickenham on a Saturday morning on ... what was it, the 92b? something like that... to go to the pictures... the memory fades, of course.

Of course, I've been in Minneapolis Minnesota, USA, now, for 13 years, and 16 years in Racine, Wisconsin before that...

I'll try the homebrew solution as soon as I get the carbs back from Steve in Sunny Florida, and post results.

[AZBiker]

I love my Morgan Carbtune.

Fast shipping, works great.  I got the case also, case is very nice.

[julianop]

Thanks AZ, that's exactly what I heard a hundred times, so one should arrive in my mailbox early next week.

Tell me, did you (or anyone else, for that matter) ever question and/or test the relative calibration across the sticks - say, swap the tubes or connect them altogether on the same carb to see if they all show the same level? I saw during my Internet research on the Morgan that a couple of folk suspected that the calibration was off - showing different levels even when connected together - which would of course negate the accuracy and effectivity of the device.

[MAN OF BLUES]

I personally push the Twin-Max electric tuner on everyone that asks, simply because it overshines anything on the market when comparing 2 sources, which is what you are doing on a bank of carbs. you are actually synching 1 to 2, 4 to 3, and finally 3 to 2.

I feel that there is no gage on the market that is identical between 4 completely different gage sections, therefore any 4 circuit gage has shortcomings.
as for the twin_max, I have no problem synching with the fuel in the float bowls with the tank off... The accuracy and finite adjustment of sensitivity on the gage is outragiously superior.
I have placed the Morgan "inline" with my Twin-max and shown people this fact.
same price, just a better product.
jmho/ymmv

[AZBiker]

Thanks AZ, that's exactly what I heard a hundred times, so one should arrive in my mailbox early next week.

Tell me, did you (or anyone else, for that matter) ever question and/or test the relative calibration across the sticks - say, swap the tubes or connect them altogether on the same carb to see if they all show the same level? I saw during my Internet research on the Morgan that a couple of folk suspected that the calibration was off - showing different levels even when connected together - which would of course negate the accuracy and effectivity of the device.

Nope.  Didn't even need one for years.  When I bought the Connie, it was the first I'd learned of the demise of the mercury carb sticks.

[julianop]

M.O.B. I get your point - it is very valid.

Actually you've got me thinking of a pet project I conceived based on my early thoughts along those very lines (the implicit inaccuracies in a 2/4 channel mechanical system vs the implicit accuracy and adjustable sensitivity and filtering ability of a direct differential electronic system). I was thinking of designing an installable 4 panel-mount channel electronic balance indicator. It would be the first step toward a more capable engine health monitoring system.

I'm an electronic systems engineer by trade, and have a decade in avionics, so I'm very familiar with electronic measurement of air pressure - glass cockpit altimeters and engine control systems use it. It occurred to me that I could design a system that electronically measures and monitors the pressure of all four intakes during all phases of operation and displays that on a compact graphical, digital display. I think I'll open up discussion on this subject in a separate thread, and get some opinions on usefulness and practicality.

Meanwhile, of course, I've put my money on the Morgan Carbtune, and it won't hurt me to gain some experience with that device before I presume to design a fancy replacement.

[MAN OF BLUES]

it's hard enough making people keep track of the road and riding safely, adding a new dash mounted farkle for folks to look at (can't adjust the carbs while riding so it's just another set of gages to look at) might be a dangerous and distracting thing...
once you synch the carbs, it's a bit moot, and yo shouldn't have to be monitoring constantly....cause they ain't gonna change....if they did, you'd feel it for sure, before seeing it on a gage.
but inventions are cool....

[julianop]

Again, a very valid argument. Maybe not worth my effort then... darn, it would have been a fun project ;-)

Is that true, though? Do carbs really stay sufficiently in sync, once adjusted, that periodic checking and readjustment is not worthwhile? I had heard about one guy who rechecks his every oil change.

Part of my thinking on the panel gauge is that vacuum pressure is - in the car world, anyway - a relative indicator of power. On a four-barrel, four-carb engine there's the added complexity of effects of imbalance, so some kind of indication might be a helpful diagnostic.

Alternatively, a single indication of "imbalance" set at, say, 2mmHg, might still be helpful. Such a light would blip and flash during acceleration, etc, but it would still be a helpful - though less distracting - indicator.

[Nosmo]

That makes me think of pilots I used to deal with when I was an aircraft mechanic.  Give them a single-point EGT (Exhaust Gas Temp) system and they were relatively happy to have something to play with on long flights.  Give them a 6-point CHT/EGT engine analyzer and they would be in the shop every day whining about something being “off”.  “At 75% power, #2 cylinder is 21 degrees cooler but at 82% power, #4 is hotter than #6 by 11 degrees, but the CHT is 8.5 degrees cooler, but my total fuel flow is high by .00326 GPH, and I’m SURE it’s running rough because….” 

Geez. 

I agree with MOB, you’d spend so much time worrying about your carb data, you’d forget to ride the bike.  And I suspect your "imbalance" light would drive you nuts, since the relative vacuums will vary some as the RPM's go up and down.  The idle balance can be different than the 3,500 RPM balance, so where do you set your base-line reference? 

I have the Morgan unit, and it may not be the best, but for me it’s close enough and I don’t have the buzz, and it idles pretty good, and I get 45 MPG, sort of, and I’m too lazy to try for perfection anyway.  I check my balance usually in the spring and fall (just did it two weeks ago) when the air changes around here, and/or when I put the carbs back on after cleaning.  Adjustments have been minimal for several years. 

[julianop]

Yes, I'm with you there, Nosmo. CHT/EGT on a Connie, now that would be funny. Obviously the aviation "Connie" association is not lost on you, I know it isn't!

OK then, the votes are in, the four channel panel mounting electronic vacuum gauge/carb balance indicator is off the drawing board unless somebody comes to it's defense :-)

Maybe I'll do a workshop version that hooks up to a data acquisition system and gives you a four-channel chart recorder trace on a full size PC screen with averaging and differential indicators...

Yeah - in my dreams. If nobody wants it then it isn't worth it. I guess I must just be bored at work and need a good meaty design project to get my teeth into.

I guess I won't mention my idea for a servo-controlled balance adjuster system, to actually automatically adjust the sync, then... ;-)

[Nosmo]

Nah, don't let us discourage you, at least that wasn't my intent.  More power to you or anybody who has the skill to come up with cool farkles.  Where would we be if someone had talked Steve out of pursuing his 7th gear mod or the 2 minute mod for the carbs?  I'm just lucky to be able to change my oil a couple of times a year without setting the thing on fire, and as long as it runs on at least 3 1/2 cylinders 95% of the time, I'm happy.  Others require or desire more exacting performance.  Nuthin' wrong with that.  I've been thinking for a long time about how to fab up a carburetor flow bench that would allow setting of actual fuel flows on a volume basis and had it about 1/2 way figured when I lost interest.  Maybe some day.  (Don't hold your breath.)

[julianop]

Well then I'll keep it stirring around in my mind on the few remaining trips on the bike from MN to IL I can swing yet this year.
Flow bench ... interesting idea. Yes, that would be a valuable tool. There are some pretty fine fuel flow rates right there, especially down at idle. They would be hard to measure with any transducer I know of. The other part, of course, is that gasoline is volatile substance, "known to cause cancer in the State of California..." etc, and we aren't really supposed to be dumping it out into the atmosphere. We'd have to come up with a reclamation system to be fully legal. I doubt there is another substance we could use in place of gasoline that would behave the same in a carburetor. Those two Italians - Bernoulli and Venturi - if only they knew how much trouble they caused ;-)
This discussion should be in another thread of course, though this is a fine time to be saying that!

Another thought on the vacuum monitor idea: I could make it "blind" i.e. no display, just a data acquisition system. It would acquire pressure data over a period of time, and you could then hook it up to a computer and analyze the data afterward.

A question - probably best directed to Steve in Florida, as he's the carb guy:

The vacuum port on one of the carbs goes to the airbox, doesn't it? And one to the petcock? The petcock feed is a static pressure tap to operate the shutoff, but the airbox connection - doesn't that affect the vacuum on the inlet it's connected to and mess up the sync job ?

[Steve in Sunny Fla]

the 49 state model doesn't have any vac hookup to the airbox. #2 goes to the petcock. 1+4 t together to the pair valve. 3 is closed. I'd pull the pair system and cap 1-4 also. HTH, Steve

[julianop]

pair valve? what's that?
and is that a recommendation?

[julianop]

I've finally managed to re-install my carbs, cleaned and modded by SISF with overflows and jets for the cam mod (to be done next). I had to wait for the Morgan Carbtune I ordered, then my buddy got sick and couldn't help (bike was in his garage, I didn't think it decent to have him miss the fun).

The carbs went in easier than they came out - once I had the sense to temporarily remove the breather tube that runs back to the top front of the airbox. The carb block slid in high, and it was easy to tilt the front sides down and direct them into the front rubbers, then work the back rubbers around each inlet port and finally do up the clamps and run the springs into their channels. The cables were no more trouble than I expected them to be (just a slight taking up of some slack on the pull side). Steve's foam mod was a breeze (once I found the instructions I'd mislaid almost two weeks ago), as was the overflow drain tube set . Finally, with the temporary loan of an old lawnmower tank and a gas-line filter to prevent me from ending up back at square one, I was ready to tune.

It took no more than 10 minutes to sync the carbs with the new Morgan Carbtune (no sucking of fluid into the cylinders), readjust the idle to just showing the white line at 1000RPM and run round one the screws more time.

At 9 PM this evening I ran a little fifty mile jaunt around the block - a mix of subdivision, country roads, and freeway. It was 34 degrees out when I got back, but I'm happy as a pig in poop. The engine is purring and humming happily, as smooth as a baby's butt, and not a hint of misfiring. For the first time ever my hands aren't sore from vibration, and all of a sudden somehow I find myself totally content with the engine running at 3000 RPM and above: it doesn't sound labored or uncomfortable like it did before; it sounds like it's meant to be there (which you all have been telling me all this time, of course). I love that smooth harmonic hum I get when I change up from second into third and wind it up to around 60, and she just wants to keep going past 75 like she's just waking up.

Down around 2000-2500 it glides quietly down Main Street with no chugging, growling, or surging; a nice constant speed and smooth transitions as the load comes and goes with slight hills. I can roll on and roll the throttle very smoothly without jerking and without the need to clutch through a transition from slowing to speeding up and vice versa. Finally, it pulls away from a dead stop as smoothly a boat leaving shore.

In short, my motor is excellent. As if there was any doubt to be had, Steve's cleaning and mod did wonders, and I don't even have in the new cam it's jetted for yet. I now know what you have all been singing about all this time, and I'm finally happy I bought the Connie.

Thanks for your excellent work, Steve. Not that you need any more accolades, but if anyone is lurking and is on the fence over SISF's carb mods, quite vacillating and get it done! Thanks also to all the other experts here for your advice and opinions - I certainly had plenty of those to chose from ;-)

Next stop, Steve's cam project over the winter, just in time for the start of the 2012 season, and the 7th gear mod will probably get done on my first new back tire, as the wheel has to come off for that too, apparently ;-)

[Steve in Sunny Fla]

So maybe a decent running connie isn't all that bad, eh? The plan here is to get you not thinking so hard about the BMW's, though i realise that IF you have beemer lust it's a going to take alot to satisfy it. Cams next, and that's another big personality change... Thanks, and glad you're liking it - Steve

[SteveJ.]

A sweet running Connie is like a fine wine beer.

Glad yer all squared away on the carbbie issues. Wait till ya get the cams in. That will put an even bigger grin on yer face.