How to get the boots back into the Airbox

[DaveC]

So there I was trying to figure away around removing the air box when syncing the carbs. No way you gotta remove the box, go ahead and just pull it. Save yourself some grief.
Now putting it back on this is where it drives people nuts. It is easy if you know a thing or two. Here they are.
You need a 12 inch philips, not only do you set the carbs with it you well use it to get the boots back in place.
The trick is poke the boot through the hole, starting towards the center of the airbox or furthest point then work your way back around. Go in from here:


and from here:


They pop right in. The secret being the philips doesn't hang and it is long enough to get to where you need it. . Trying to pull them through is near hard or impossible, pushing them through with a circular motion is quick and easy. I tried the pull approach, takes forever and it just hard to do.

Now you have no excuse, go sync your carbs, I use a Carb Tune Pro. great tool.

[David (N. Alabama)]

Nice pics. What is the red, white and green ribbon around the screwdriver handle?

Another way to get the boots back into the airbox that was discussed on this forum is to wrap string around the boot and pull it into the airbox. I tried it and it worked great.

[DaveC]

Nice pics. What is the red, white and green ribbon around the screwdriver handle?

Another way to get the boots back into the airbox that was discussed on this forum is to wrap string around the boot and pull it into the airbox. I tried it and it worked great.

That is a MV Augsta camera strap Picked it up at the IMS a few years back. The thing with the string is if you use a small nylon it may cut your boot. I did not have any string of the desired diameter. I have mason line. Since I had the screwdriver handy I used it.

[ekap1200]

Hello DaveC, hope this help ya., I use a automotive carb adjuster tool, this one shown is from Mac tools but there are still a few out there by others. If you know any car mechanics they will have one they havn't used in years since injectors are the norm now. makes carb sync' a breeze, just need to hook up the vacum lines and presto , ready to adj

[Steve in Sunny Fla]

Hello DaveC, hope this help ya., I use a automotive carb adjuster tool, this one shown is from Mac tools but there are still a few out there by others. If you know any car mechanics they will have one they havn't used in years since injectors are the norm now. makes carb sync' a breeze, just need to hook up the vacum lines and presto , ready to adj

OK, splain it to me - how are you using a single vacuum guage to sync the carbs. I see the hose system you built, but it all feed to one point and therefor only gives a common vacuum reading as shared by all 4 carbs, like checking vacuum on a 4 cyl automobile. Since you can't compare one carb to the next - the purpose of carb syncing - I don't see how this can actually sync the carbs. I must be missing something, please enlighten me - Steve

[Furchin]

I can see how that set up would work if it has valves or shut off points on each line to check vacuum individually, other than that I agree with you.

[Steve in Sunny Fla]

I noticed the "nubs" in each line, made me wonder if it was some type of shut off valve. Still, I've tried to use vacuum guages to work on M/C carbs without much luck. even with a tiny inline restriction, the un-damped needle fluctuated to much for a consistent reading. Steve

[ekap1200]

Hi guys, these valves are precision flow control valves from (SMC inc,) Aside from purchacing 4 calibrated vacum guages at considerable expense I have always done carbs this way, learned it from a racer at a Honda,Kaw dealer I worked for, back in the late 70's. Can't go wrong with one guage, I warm up the bike, having paper and pencil go from 1~4 cracking open one valve/closing, then the next, and write down the vacum. The valves are shown in the pic they are very small. Knowing which way to tweek the throttle adj. screws to go up or down on vac. is a must. And this will take some time for most to get used to. Closing the throttle plate vac increases; opening decreases. I then adj. screws and recheck 1~4 again. Using the one guage you can never be off on adj. due to one of your gauges being off calibration, ( like most guages are )
The whole job takes me about a half hour and the proof is in the smooth idle. Of cource you carbs have to be in great condition so that the pilot jets are clear of restrictions. But thats it, hardest part is not dropping vac pipe caps down onto the engine where they get somehow lost ! but throw a rag over the alternater area to avoid that. Working as a mechanic for most of my life we never removed more that neccesary to do the job, and there is no risk of crap getting sucked into the intake while the engine if running, Oh and you never have to mess with those carb boots !! Hope this helps and smooth idleing to all. Gene Kap.

[Steve in Sunny Fla]

Thanks, and I appreciate you including where you got the precision valves from. I have mercury stix, but I needed a precision air valve for another application.

Also, let me share something with you that I found pretty surprising - clogged pilots or closed idle fuel needles WON'T effect the sync at all. I know it's completely against all intuitive thought. I found this by syncing and then closing off the idle fuel supply on various carbs while watching the mercury. When a cylinder is killed all the vacuums would drop abit but the sync was maintained, including the cylinder that was dead. HMMM. I finally figured that the other cylinders were spinning the engine and so the dead cylinder was still pumping air, just not making power. The overal vacuum drop was due to the less rpms due to the dead cylinder; idle the engine back up with the throttle stop and the vacuums all come back up too, including the dead cylinder. Interesting. Steve

[ekap1200]

Steve , that is an excellent topic to cover, One should always keep in mind a smooth idle is both a combination of fuel,air and spark timing. Often people will confuse a poor idle to (my carbs need sync.) Maybe-but maybe not. Had a customer ask for a carb sync and it turned out a mouse had made a nice little home on top of the air filter over the winter season. changed the air filter, drained the carbs,(clear fuel showed )engine ran smooth and carb-sync was fine. So its always good to look at the big picture when working on any engine. I always keep a good eye on fuel filtering and cleanliness when working with my carbs and we all as bike owners know if our machines have changed the way they are running which somtimes is a good troubleshooting hint, ie. just got gas at hobo-joes gas station ( 10dollars in gas and two free ounce's water) or gee havn't changed that air/fuel filter in while. Iv'e had customers tell me they just changed the air filter now the bike doesn't idle good, well I ask them just how much crap fell down into the air box when they pulled the old one out? Gee just a little, well one grain of sand is as bad as 20 if it goes into the idle air inlet , or down into the cyl. But I could ramble on if no one stops me, My grandfather used to say about the mechs under his charge. " Its not bad too not know, but when you don't know that you don't know , thats when your in trouble" And thats all I got to say about that. Ya'll have a great New Years day and its almost riding season soon. Gene Kap.
PS using the valves with a guage you just crack them open a hair and close them slowly to get your needle to stop fluctuating.

[Bill O]

My grandfather used to say about the mechs under his charge. " Its not bad too not know, but when you don't know that you don't know , thats when your in trouble" And thats all I got to say about that.

I have a saying that is somewhat similar.......

"It's usually not what you don't know that gets you into trouble, it's what you do know, that ain't so!

Bill O

[Steve in Sunny Fla]

Gene, I agree on all counts. Im really comfortable with carbs,but to most folks its a french word that means "don't mess with it". I do alot of work for the concours folks, I have a jet kit I offer and a second one I'm developing now. Guys send me carbs from all over. They have usually been working on them on thier own, and have really messed them up. Of course since they don't know what to really look for, they generally overlook the real issue and mess the carbs up more trying to fix them. Trying to diagnose a system you don't understand is a real exercise in futility. Steve

[Steve in Sunny Fla]

BTW - while I did sync my voyager at idle, I've found it best to sync the concours up around 5000 rpm. Here's why. 1) the connie has a lumpy idle due to the cam overlap so they never give a dead smooth idle, even with a perfect sync ; and 2)the engine is solid mounted to the frame as a stressed fram member, not rubber isolated like the voyager. Therefor all vibes go right into the frame, handlebars, pegs. Can you say BUZZ? I've found that syncing at 5000 allows all the throttle shafts to stabilize across the cylinders, so at that point the sync can be made very consistent. As you pull the rpms up, one cyl will pull ahead, than another, etc, till the shafts become stable and then they'll all remain consistent from cyl to cyl. Syncing once that throttle rod slack has been removed goes along way to reducing the buzz when riding. for those not so mechanically oriented, keep in mind that 5000 rpm sitting on the center stand in neutral is probably equal to 12-1500 rpm's worth of throttle opening in 1st gear. Really, it's just enough load on the shafts to get everything stabilized. Steve

[ekap1200]

Steve, I hear ya. Read some where on one of these forums, " If it ain't broke, fix it until it is"
Got a real laugh from that one. But honestly I don't mean to poke fun at those of us who havn't been blessed with growing up as DIYers. I truly feel thier pain being at the mercy of others to repair bikes,cars, heaters, or wiring. Some might say we are blessed with a gift, but if you do it for a living it feels sometimes as a curse. Gene Kap

[ekap1200]

Hey Bill O, sorry to not get the close up pic or the dimensions of the hiem-joint posted today.
After the party we were at last night. (wife drove us home ) Things thismorning were a bit foggy and she was off work. So no shop time for me today, its rare we both have the same day off.

[ekap1200]

Anyway lets get back to Dave C, after all the work you did getting the air box off and adjusting the carbs. How did it all turn out? The Job went well I hope, and all is back in order. Gene

[SilverBullet]

Hello DaveC, hope this help ya., I use a automotive carb adjuster tool, this one shown
is from Mac tools but there are still a few out there by others.
If you know any car mechanics they will have one they havn't used in years since injectors are the norm now.
makes carb sync' a breeze, just need to hook up the vacum lines and presto , ready to adj

I tried using a set-up similar to this yesterday to check my carbs but the needle on the vacuum guage
just bounced around super fast. Impossible to get an accurate reading from it. Thought maybe the gauge
was faulty so went out and got another brand/type and same exact results. What type of guage are you
using and/or what is the trick to make this work? Are you restricting the input into the guage? I couldn't
find any valves like you show so was using straight hoses from carb to guage.
Here is the first guage I used:
http://www.harborfreight.com/cpi/ctaf/d ... mber=93547
This was second one:
http://www.autozone.com/autozone/catalo ... ame=Sunpro

[ekap1200]

Hello David, If you look real close at the pic and have read the posts, there are four small flow restricting valves installed it the lines. One has to only crack them open until you see a vacuum appear at the gauge.
Without restricting the vacuum and closing off the other three lines this will not work and the gauge WILL do what you are seeing . Plus you are seeing vacuum from all four cyl's. without the valves. I will try to find a link for the valves I used Gene Kap

[SilverBullet]

Hello David, If you look real close at the pic and have read the posts, there are four small flow restricting valves installed it the lines. One has to only crack them open until you see a vacuum appear at the gauge.
Without restricting the vacuum and closing off the other three lines this will not work and the gauge WILL do what you are seeing . Plus you are seeing vacuum from all four cyl's. without the valves. I will try to find a link for the valves I used Gene Kap

Aah so the valves are the trick, restricting input by fine metering. I thought the valves were only for convenience of keeping all 4 vacuum lines connected.
I did search SMC and their local distributors, Fastenal, etc but couldn't find anybody that had them. Only valves I could find locally would have made my set-up more expensive then just buying a dedicated carb sync tool.

I didn't connect all 4 lines together. I capped each line and only put one line at a time on the guage. Low rent method but would have worked just taken a little longer for on/off of guage instead of turning valve. Of course that was before I now know valve serves another purpose.

_

[SilverBullet]

Hello David, If you look real close at the pic and have read the posts, there are four small flow restricting valves installed it the lines. One has to only crack them open until you see a vacuum appear at the gauge.
Without restricting the vacuum and closing off the other three lines this will not work and the gauge WILL do what you are seeing . Plus you are seeing vacuum from all four cyl's. without the valves. I will try to find a link for the valves I used Gene Kap

Aah so the valves are the trick, restricting input by fine metering. I thought the valves were only for convenience of keeping all 4 vacuum lines connected.
I did search SMC and their local distributors, Fastenal, etc but couldn't find anybody that had them. Only valves I could find locally would have made my set-up more expensive then just buying a dedicated carb sync tool.

I didn't connect all 4 lines together. I capped each line and only put one line at a time on the guage. Low rent method but would have worked just taken a little longer for on/off of guage instead of turning valve. Of course that was before I now know valve serves another purpose.

_

Had an afterthought. I think I'll go buy a single valve. I found one for under $10. Then I can use that in conjunction with my one at a time line set-up. Drat I already returned the Harbor Freight guage. Oh well I'll have to use up another one of my 20% off coupons.

_