Carb/Throttle Body Synchronization

[Stinky]

Well I finally got to synching my carbs. Thanks to Paul, I was able to make my own sync tool from this link:

http://www.airheads.org/contrib/4dollarmano.html

And all I spent was $1.50 for 15 feet of clear vinyl tubing. Instead of a yard stick I used a level that was in the garage. That extension tubing mod by Carolyn Boyce makes the job a helluva lot easier. Once hooked up, it looked like my bike had an IV flowing. Turned out my carbs were way out of sync. I'll probably ride out tomorrow to see if I even notice a difference.

[bwarbiany]

I'm guessing you'll notice a difference. Specifically, it should improve your throttle response. It certainly did for me, and mine were pretty far out of whack...

Brad

[buymenow00]

Hey Stinky...I was thinking about doing the carb synching thing myself...I have the parts for the Carolyn Boyce mod, and the printout for the $4 DIY carb sync tool. When I was considering hooking up the hoses for the Boyce mod, one of the hoses was a pretty loose fit on the t-fitting. Carolyn used a wire tie to clamp it down, but that didn't seem to secure on mine, so I just shelved it as I was in the middle of carburetor hell at the time anyway. Did you encounter a similar problem? It was on the line that goes from the fuel pump if I recall correctly...very loose.

[Stinky]

Originally posted by buymenow00
Hey Stinky...I was thinking about doing the carb synching thing myself...I have the parts for the Carolyn Boyce mod, and the printout for the $4 DIY carb sync tool. When I was considering hooking up the hoses for the Boyce mod, one of the hoses was a pretty loose fit on the t-fitting. Carolyn used a wire tie to clamp it down, but that didn't seem to secure on mine, so I just shelved it as I was in the middle of carburetor hell at the time anyway. Did you encounter a similar problem? It was on the line that goes from the fuel pump if I recall correctly...very loose.

I think I did, I can't remember. I just know that I have 3/16" ID tubing and I think 1/4" valves. I remember the tubing was real tight on the carb nipples but fit perfect on the tees and valves. I also used the same tubing for the carb sync tool.

[Stinky]

Originally posted by bwarbiany
I'm guessing you'll notice a difference. Specifically, it should improve your throttle response. It certainly did for me, and mine were pretty far out of whack...

Brad

Yeah I revved it a couple times after I got everything closed up and it seemed to rev differently. Like it was smoother.

[pcperks]

Anyone have a carb sync tool that I could use when I get my jet kit in?? Or know where I can pick up one cheap?? Thanks.

[buymenow00]

You can make your own carb synching tool for less than $10.00. Do a search on this site for carb sync or synch...you should find a link to some BMW site that has instructions...if I can find it I will post it here...
http://www.airheads.org/contrib/4dollarmano.html

[Drumrboy]

Phil,

If you do the jetting, I highly suggest following the instructions on the link provided to make future carb syncing a snap. The gyrations you need to go through to get to the vacuum connector for the front cylinder are more painful than need be in stock/unmodified trim. Basically the procedure provided in the link will make future carb syncing a 15 minute affair, rather than a 1 - 2 hour ordeal. I have done this to my own bike and to another list member with great results. Parts can be found at home depot or lowes. You can find a "mercury stick" type syncing guage/tool from just about any motorcycle parts store (about $30 - $40) - I would recommend Cycle Gear on Convoy St.

http://www.bluepoof.com/motorcycles/howto/svs_carb_sync/

Forgot to mention also that according to the instructions in the link I provided, you must drain and remove the radiator. This is unecessary. When the radiator is unbolted from the frame, you should be able to pull the radiator down away from the frame somewhat and let it hang by the radiator hose to give the necessary clearance.

Michael

[airman9]

I just pulled my radiator forward as far as I could get it.. (not much by the way) and it was a pain but I finally got the hose on the front one... As for the mod to do to make carb sync easier... I found that you only need to do the front one as the rear is very easy to get to. If you do both hoses you can check your sync easier but it really isn't hard either way...

I also have the mercury carb tool ($38.00) at Cycle Gear on Convoy and it I feel made things so much easier to do.. It is east to read and the only thing was we had to add a T fitting to one of the hoses to connect to the back carb..


Hope that helps...

[ham]

hey, im new to the community. i recently purchased my sv and last weekend started my 600 mile maintainence, but found an impass at the carb sync. am i unable to do this without the balancer tool or is there another way to do the sync ? any info would be most appreciated as im sure others who do their own maintainence have run into this. thanks.

[gaian]

there are two aspects to carb balancing: synchronising the opening of the butterfly valves which you can do without a special tool. Setting the vacuum to match on each cylinder I don't think is possible without some kind of indicator..The simplest kind is a simple liquid filled (usually Hg) tube. This guy said his was very cheap:

http://www.powerchutes.com/manometer.asp

..but you'd still need the adapters for the Suzi's carbs. Lastly I heard a claim that you can listen to the hissing sound from each carb and balance the sound...not sure I believe it or how accurate it would be anyway.

[linp]

Try a "Search (http://www.socalsvriders.com/forums/search.php)" on "carb sync" should give you many info.

[neetones]

I did a carb sync this weekend and while I was putting my radiator back in place, I sheared two of the mounting bolts in half, leaving half of them in the frame (moron.) Well, I got the one on the left side out, but the upper right bolt (next to the filler cap) is jammed in, I've tried pliering it out, WD-40, but it doesn't budge. What can I do? I feel like an idiot amateur wrench (which I am) but I need to do something about this besides taking it into the shop. can anyone help?

Nitin

[GMAN]

Stop by an auto parts store (Kragen, Pep Boys, etc) and buy a bolt extractor. It's pretty cheap, and you'll need a drill as well.

http://www.socalsvriders.com/forums/showthread.php?s=&threadid=3053

[Q]

The only thing I can think of is to use the bolt extractor like Gman says.... but be careful not to rip out the threads on your frame. if you do, consider your bike a loss. I don't know of a shop that will re-tap a threaded hole in aluminum.

[GMAN]

Originally posted by Q
I don't know of a shop that will re-tap a threaded hole in aluminum.

Do you think a heli-coil might work? It works fine on an aluminum head (on a cage), but then again...a bike frame is much different (and thinner).

Hmmmm....

[sarge]

i don't remember having to take the radiator off to do a carb sync:confused:

did you take that off instead of the carbs or something?

[neetones]

no, I didn't confuse the radiator for the carbs, I'm not that inept. I only loosened the radiator so I could more easily get to the front carb vac. nipple.

I'm really at a loss though, besides feeling like a tool I don't want to further screw things up.

how does the extractor work? there's not much thread left sticking out. (never mind, I just checked out that link. Thanks, I'll give it a shot....but it's damn well stuck in there.)

Nitin

[Danny]

Yeah those bolts shear easily. Likely you can just notch the bolt shaft and unscrew, otherwise drill and extract. Then replace all with quality bolts, locktite and snug tight. If the threads are trashed, just drill and tap larger. They're not critical so don't worry too much, just get something in there and go ride.

[sarge]

Originally posted by neetones
no, I didn't confuse the radiator for the carbs, I'm not that inept.
Nitin

what i meant was the radiator VICE the carbs. if you pull the carbs, connect the vacuum tube, and then reconnect, you don't move the radiator. i suppose moving the radiator could be easier than moving the carbs. i didn't think of it. anyway, i don't think your inept:p . good luck with the extraction. it's not too hard, just tedious. i don't have patience for that kind of stuff, so i'd be taking it to someone else. then it becomes expensive

[Q]

Originally posted by GMAN
Do you think a heli-coil might work? It works fine on an aluminum head (on a cage), but then again...a bike frame is much different (and thinner).

Hmmmm....

a heli coil may work.. but I don't want to suggest that for something on the frame. A fellow TL rider ran into a 3rd party TL rider trying to part out his TL because he broke off a bolt in his frame. No shop in San Diego would touch it. They said by tapping and making it larger that it could weaken the frame. I'm not sure about where the radiator mounts up though. But as Danny said, it might be an insignificant point and not affect the strength of he frame.

Good luck with it neetones
:vic:

[kb426]

Do not try the easy out. Take it to someone who is experienced and have them do it. You have to drill exactly in the middle of the broken bolt to have a good chance of recovery. If everything gets messed up, I think you can have a machinist install a helicoil and be ok. Because of your lack of experience, I would strongly encourage you to seek help. There are many ways to mess this up.

[BioTek]

I'm looking at getting a manometer for carb synching, I have a Grainger catalog at work and there are a bunch of different options I can go for. What kind of vac does the SV normally pull at the carbs? I dont wanna get something that measures to 10" vac when they pull to say 15". Thanks.
I'm thinking a slack tube manometer thats good for 30" vac will do what I want?

[abkwanabe]

SDSV,
You did not think much of my manometer? For $4 you get a lot of tool. It might look kluge but the science behind it is sound.:confused:

[BioTek]

Originally posted by abkwanabe
SDSV,
You did not think much of my manometer? For $4 you get a lot of tool. It might look kluge but the science behind it is sound.:confused:

From checking out a variety of different options at Graingers and remembering your set-up, I know they are all very serviceable, and thats yours included, so dont be offended Donn.
I have decided that I am going to go the homemade route, did you use straight coolant in the hoses or a water/coolant mix?? I have the parts I need to hook it all up, just need to buy a long straight ruler to tie the hose to.
I plan on trying it all out next Saturday.(I'm going to change the plugs too seeing as the radiator is going to be dislodged.) :D

[abkwanabe]

Chris,

I used some left over fork oil because it was colored green as opposed to clear. If you have some left over Automatic Transmission Fluid (usually red in color) that would also work. I would not recommend water/coolant as the viscosity may be too low to be useable. I would be interested in seeing how to change the spark plugs. The service manuals schedule seems low, especially when you consider new cars change their splark plugs at 30K or 60K miles.:D

[BioTek]

Originally posted by abkwanabe
Chris,

I used some left over fork oil because it was colored green as opposed to clear. If you have some left over Automatic Transmission Fluid (usually red in color) that would also work. I would not recommend water/coolant as the viscosity may be too low to be useable. I would be interested in seeing how to change the spark plugs. The service manuals schedule seems low, especially when you consider new cars change their splark plugs at 30K or 60K miles.:D

Come on over if you want, I'll PM you directions if your interested.

[GraVitY]

Ok, I've done a search and still can't find this issue resolved, so I'm posting. Not only that but the bluepoof site that explains this is down so if anyone can help that would be great. My question is this: Where are the hoses located to tap into on the front and rear carbs to syncronize them? I know there is a hose on the front and the rear that needs to be tapped into in order to synch but where are they located? What am I looking for? Is there a specific hose or do I just choose one? I'm lost at this. Any help would be greatly appreciated.

Grav.

Ps. Please don't post the site for bluepoof, it's down and the pics won't load for some reason, they just appear to be x'ed out.

[abkwanabe]

The front connection that you would be looking for is actually a black rubber/plastic cap covering a brass tube at the forward end of the front carb. The rear vacum hose is the hose assembly that goes from the gas tank to the rear carb. I say hose assembly because there are saeveral hoses and a T connector that is part of the assembly. Good luck.

[GraVitY]

Thanx man. I'll look into it.

Grav.

[linp]

In case Bluepoof.com is still down, here (attached) is the carb sync instructions.

[Chicago_SV]

Why and when is it time to do so? I rejet my bike (2001 non ca version)
2 years ago runs fine. Is ther a tell tail sign that this procedure needs to be done or should I just leave it be

Thanks

Michael


nice write up here with the home made meter

http://www.kuhnco.com/SV650/SV/Throttle_body_synchronization.htm

[kc1717]

hey there was a carb sync guage on CL for cheap.


the nice guage type, if anyone is interested

[SVSmiles]

Originally posted by kc1717
hey there was a carb sync guage on CL for cheap.

the nice guage type, if anyone is interested
I'm interested... I'd rather have the real thing if it's in a good $ range. Where is CL?

Anyway, for now I went ahead and pulled the air cleaner box again even though the carbs had looked to be pretty close in sync at 1300 rpm (idle) so I could experimented at what would happen when throttled up at 3000 rpm and then synced. The result sent the SVS here out of sync when dropped back down to 1300 (idle) rpms. Sooo, I put it back to the service manual's 1300 rpm sync.

MAN, that synchronizing screw was touchy it would be close and the slightest tweak in the other direction and it would send the engine's purring off out of sync. It was like trying to find that certain 8-} spot on your GF that gets her all =P~ @-) :love:

She's all :D now... ;)

[kc1717]

yeah it was a nice one,....25 $


cl=craigslist


i looked again and couldnt find it,..maybe its sold from this morning, but ill check again,...

it was a real nice one

[BioTek]

Erm, I synch at 3k as I'd sooner the throttle response is crisp and even when I'm on the gas, it doesn't bother me if it isn't perfectly smooth at idle, it aint gonna be that far out anyways. :)
For what it's worth I do it with the airbox off and tank up and I have the mercury type manometer.

[SVSmiles]

Originally posted by kc1717
yeah it was a nice one,....25 $ : cl=craigslist: i looked again and couldnt find it,..maybe its sold from this morning, but ill check again,... it was a real nice one
I did a search for the list and found it. I also think I found the > Sync Tool (http://www.craigslist.org/eby/mcy/49237335.html) < noted earlier. It looks like it might be a fair deal, but two things are keeping it from working out. I'm no where near where the seller is located and due to the mercury it's a pick up only item AND I was hoping for a good $ on a more compact unit I could store better and even take it mobile should a maintenance day come up, rather than the current yard stick type.

I appreciate the heads-up though... ;)

Originally posted by BioTek
Erm, I synch at 3k as I'd sooner the throttle response is crisp and even when I'm on the gas, it doesn't bother me if it isn't perfectly smooth at idle, it aint gonna be that far out anyways. :)
For what it's worth I do it with the airbox off and tank up and I have the mercury type manometer.
That's a good point BT... How's the engine respond during those lower rpms before it hits the 3000 synced range? Say like during a need for a quick launch in a Get Me The F-Out of HERE Way with a cage coming down on one's :ass: at a stop light/intersection :confused:

[BioTek]

Originally posted by SVSmiles
That's a good point BT... How's the engine respond during those lower rpms before it hits the 3000 synced range? Say like during a need for a quick launch in a Get Me The F-Out of HERE Way with a cage coming down on one's :ass: at a stop light/intersection :confused:


I tend to give it a decent handful of gas as I release the clutch gradually anyways so I'm well above 3k and into 2nd before I think about it so, erm...fine I guess.
It doesn't really run that much rougher if it is slightly out so no big whoop really. I just want things running nice and smoothly mid corner etc, you know? I've never seen any hugely noticable difference when it's been out of sync, but that's just me possibly.

[slowmike]

anybody get this? mnnn; I want one. but can't really get my butt up there just for it.

[Rocko]

get what, mike?

i was thinking of getting one of these peyump carb sync tools with all the money i'd be saving by doing it myself.

has anyone had any experience with one of these?

http://www.casporttouring.com/store/merchant.mvc?Screen=CTGY&Category_Code=twinmax

[DOC]

Originally posted by Rocko


has anyone had any experience with one of these?

http://www.casporttouring.com/store/merchant.mvc?Screen=CTGY&Category_Code=twinmax No, but it looks interesting.
DOC

[deaner14er]

Just synched my carbs with a home made manometer that uses mil-h-5606 hydraulic fluid. It was extremely touchy, but what a difference. I also made the following mod allowing easier access to the vacuum lines. Mine works well, but I wonder about the lines getting brittle because of the type of tubing and the heat. This lady is an excellent technical writer.
bluepoof (http://www.bluepoof.com/motorcycles/howto/svs_carb_sync/)

[sandie]

she's really nice too :D

[harbiho]

This was previously discussed in this thread.

http://www.socalsvriders.org/forums/showthread.php?threadid=281&highlight=synch

This should be merged into it.

[SVSmiles]

Originally posted by deaner14er
I also made the following mod allowing easier access to the vacuum lines. Mine works well, but I wonder about the lines getting brittle because of the type of tubing and the heat.
I bought some GoodYear engine hosing from a local autostore thinking this very same thing. Keep an eye on it and if it needs replacing, next time use the kind made for engine use. ;)

[deaner14er]

Think I'll do it sooner rather than when I develope air leaks. This is not a 2 day job. The whole process took about 2 hours. This clear vinyl tubing dos not like gasoline, either.

[Willdahthril]

Did the carb syncing with the home made $4 tool that costed more for me. My hardware store charged $.75/ft for that tubing. Anyway I understand that the home-made tool is scientifically sound and all, but what about the re-routing of the vaccuum lines to make them more accessible for future carb syncing. I guess I'm wondering if the length of tube from each size matters. Will you get a different reading when hooked up directly to the carb nipples vs. an extended hose of a ft or two +/- a few inches here and there. Won't vaccum pressure dissipate as the length of the hose increases? I hope someone can clear this up for me, I'm a bit puzzled.

[D.T.]

I put a plastic "T" on my rear vacuum line and a short piece of vacuum hose which I plugged. On the front carb, I put a piece of vacuum tubing about 8" long to a valve in the fairing. This makes sync'n a snap. You shouldn't have to have the hoses over 8" long.

Vacuum will not decrease on extended pieces, except for the hose collapsing and a leak. This is why you buy vacuum specific hose. Autos have miles of vacuum hose under the hood.

[rcmark]

I have a 2001 SV650 (CA Model) and want to sync the carbs.
I have established the front carb sync (vacum) line.
On the rear carb there are a two vacum lines.
One goes from the gas tank valve to the rear carb.
One goes from the fuel pump to the fitting that holds the rear carb to the engine.
Which line do I use?
Can I put a “tee connector” into one of these lines?
Any ideas?
Thanks,

[TLRDoug]

I use one of these, $178.00 from Suzuki, but it can be used on anything...........works great.

Click for a big 'un

http://photos.imageevent.com/tlsdoug/dougstuff/biketools/websize/P7030010.JPG (http://photos.imageevent.com/tlsdoug/dougstuff/biketools/huge/P7030010.JPG)

[angrymfer]

Does anyone know if these types of carb sync tools are more accuracte than the vacuum gauge type?

I suppose from a calibration standpoint, they may be - e.g. all of the gauges need to be calibrated so that they match, whereas the mercury tubes are simple enough to not need this so much. But I might well be talking out of my ass here.

[Rocko]

I bought one of these (http://www.casporttouring.com/store/merchant.mvc?Screen=CTGY&Category_Code=twinmax) , it is the shit.

Prior to that I did the thing where you hang some clear tubing off the engine and that other tube you cut into to make it easier to check the sync in the future....don't do this. those mercury tube things suck, too. the tool above measures the difference between two vaccuums so it's much easier than watching two mercury levels bounce up and down. your tubing has to be exactly the same length for it to work right. you're also not measuring vacuum off the places recommended in the haynes manual if you do this.

i used the haynes manual and that electronic carb sync tool, and my motor was much less buzzy after doing it. use this tool, do it right, and just buy some vaccuum caps at the auto parts store for that nipply thing on the front cylinder and your bike will run much better than if you try it the lazy man's way!

[sandie]

you still need to sync my carbs

[Doubleup16]

I just synced my carbs two days ago with the "mercury" type and I can tell quite the difference. The bike is totally smooth when it's idling and I rev it. It you to kinda studder and I din't know any better thinking it was a v-twin trait. Well its not. Throttle is much more responsive and smooth.

Rocko, that tool might be really good, but this one works well if you do it correctly. And it didn't cost anywhere near 80 bones.

[Rocko]

yeah this one i used definitely makes it more idiot proof and since i'm an idiot.....

[EviL]

idiots always find a way. :P

[smokescreen]

I would like to sync my throttle butterflies.

Does somebody have instructions on how to do this on a 2nd gen SV?

[a8ksh4]

Originally posted by smokescreen
I would like to sync my throttle butterflies.

Does somebody have instructions on how to do this on a 2nd gen SV?

I went to try and do this a couple weeks ago but couldn't be exactly sure which nipples I needed to hook up to or how exactly to fit my fingers in there to plug a hose into them. Does anyone know of a good pic w/ the nipples circled or something?

--DAn

[99x]

Just out of curiosity, how many of you have ever syncronized your throttle bodies? I just did it for the first time today, with 15,000 mi. on the bike. It only took about an hour, including me farting around constructing a monometer, and the results were well worth it.

On my last ride, my feet were falling asleep from vibration. Now the bike is as smooth as it was when I bought it 2 years ago. Huge difference! Best thing I've done to my bike in months!


EDIT: ACK!! I've been merged! The horror!!

[soulofadra6o]

hmm maybe i should sync my throttle bodies i never thought of it lol


on another note, if anyone has taken apart their throttle bodies have you noticed any gunk that has formed? im thinking if it would be worth it to take them out and clean them really good or if running some fuel cleaner type stuff will be sufficient