Making Throttle body sync easier.

[DewMan]

I"m going to be pulling my airbox soon  and want to extend the vacuum ports, used to hook up the vacuum gauge to for TB syncs, to  a more easily reached location by extending the ports while I have have the throttle bodies pulled.  I'll be more likely to do scheduled throttle body sync checks if the ports are more easily accessed.

If anyone has done this or something similar do you have recommended tubing type to use that can handle the heat of the engine long term? 

I'm planning on using a brass barbed coupler block, if I can find one, for terminating the extension tubes unless someone know of something better?

Lastly, It's been 40 years since I've done my last sync of a bank of carbs and was wondering if am I correctly remembering that both port extensions need to be of equal length to get proper vacuum readings?

 

Thanks in advance for any helpful input. 

[mossrider]

I've never synced my tb's. I wedge the throttle plates wide open and set the cables and throttle tube to match. Go zoom.

[DewMan]

So no one else has considered relocating the ports to make this maintenance item easier to do?

[shinyribs]

2 hours ago, DewMan said:

So no one else has considered relocating the ports to make this maintenance item easier to do?

Never in twenty years of wrenching have a considered this, and I have no idea why. This is a fantastic idea IMO.

 

My bike has developed a buzz that really getting in my nerves. I'm going to try relaxing the chassis on the engine ( Duke guys swear by it, worth a shot), and I'm going to follow your lead on this. I don't remember the ports being especially hard to get to, but they are a funky size compared to every other bike I've owned and hooked my synch gauges to, so if nothing else I'll address that. 

I can't remember if I had to sit the fuel tank to the side to get at the ports or the adjustment screws. 

[shinyribs]

Oh, and no, hose length won't affect the readings. Within reason, if course. You might find some variation with 20' hoses, but anything a foot or two long is going to be plenty accurate. 

[DewMan]

59 minutes ago, shinyribs said:

I can't remember if I had to sit the fuel tank to the side to get at the ports or the adjustment screws. 

If I relocated the ports out the side like I'm thinking  there won't be any reason to remove the tank at all even if you need to make adjustments if you use  an adjustment screwdriver like this one:

https://www.amazan.com/ALPHA-MOTO-Motorcycle-Carburetor-Adjusting/dp/B008LD1NOU/ref=sr_1_1?dchild=1&keywords=B008LD1NOU&qid=1599275307&sr=8-1

 

[D.A.]

Hola @DewMan:

Here's how I did my port relocate:

 

 

To make it possible I had to pull out the OEM vacuum sensing hose (the one that goes between the left throttle body nipple and the underside of the intake air pressure sensor) and splice-in a 4mm barbed Tee coupler:

 

 

After reinstalling the modified OEM hose, I attached about a foot of HPS 3.5mm inner diameter High Temp Silicone Vacuum Hose to the center post of the Tee. I trimmed the hose down after I figured out the best way to route it:

 

I opted for 4mm couplers and 3.5mm hoses since the throttle body nipples are 4mm (outer diameter) and the OEM hoses are 3.5mm (inner diameter), at least according to my measurements:

 

After trimming, I inserted a 4mm barbed elbow on each side of the bike and finished with a couple of zip ties and a rubber cap. The caps obviously get removed when it's time to hook up a manometer:

 

Here's where I bought the supplies:

https://www.walmart.com/ip/HPS-3-5mm-Black-High-Temp-Silicone-Vacuum-Hose-5-Feet-Pack/244827654

https://www.amazon.com/gp/product/B07S8CBR1W/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B07S9BTQH1/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

I used the 4mm rubber vacuum caps from this multi-pack:

https://www.amazon.com/gp/product/B008DZSZK6/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

 

I didn't reply immediately when I first saw your post because it seemed one of your primary concerns was the longevity / durability of the vacuum hose and I haven't had the hose on my bike long enough to know how well it'll do long term.

Also, I have no experience using the 90° screwdriver you linked. I did look at those at one point but prefer to simply pull off the tank covers, remove the front bolt that holds the tank on, remove 1 of the rear bolts on each side of the tank (leaving in the rear-most bolts so the tank can tilt up), then adjust the right throttle body using a plain ol' long, skinny flat head screwdriver.

Note: I had removed the tank when I took the photo below because I was changing the spark plugs that day, but it's not necessary to remove the tank to adjust the right throttle body screw – at least not on my non-ABS FZ07.

 

Edited September 7, 2020 by D.A.

[DewMan]

@D.A. , Nice looking job. Thanks for all the information. and your pictures are most helpful. 

Your choice of materials are almost identical to what I've tentatively chosen. Brass 1/8 barbed fittings and silicone lines. I'm thinking to bring both lines to under the seat I so I'll not need to remove anything but the seat to check sych while keeping them unseen.  Silicone can handle high temps (374F/190C) and UV exposure etc.. The only thing it's not good for is fuel/oil line since petroleum will eat away the silicone from what I've read. 

[D.A.]

@DewMan: In regards to using 1/8-inch fittings:

When I was prepping for this project I wasn't certain what size hoses or fittings I would end up needing so I ordered barbed brass Tees, elbows and size converters in a variety of sizes, including 3mm (1/8-inch), 4mm (5/32-inch), 5mm (13/64-inch) and 6mm (15/64-inch). The plan was to return any unused items.

I'd originally thought 3mm (1/8-inch) brass fittings would win the day but they turned out to be too small. I felt 4mm (5/32-inch) Tees and elbows worked best with the OEM vacuum hose, and 3.5mm aftermarket hose worked best with the 4mm OEM and aftermarket hardware. I was pretty surprised that such a small size difference could make such a big fit difference, but it did. (And please note, I used 4mm [5/32-inch] rubber vacuum caps rather than 3.5mm.)

But there's no reason you can't buy both like I did and return the ones that don't work.

As far as routing the hoses to the seat: Sounds like a plan!

Edited September 7, 2020 by D.A.

[D.A.]

4mm barbed brass also fits perfectly into the hoses on my Morgan Carbtune Pro 4 manometer whereas the 3mm (1/8-inch) barbed brass literally falls out of the Carbtune hoses. So, be sure to test your brass hardware with your manometer before committing to a particular size. May turn out you need a reducer to step up or down for a tight connection. (That note is really for other forum members who may be reading this. I assume you already know what size hoses your manometer uses!)

Also, since I ordered a ton of things at one, it gave me a chance to compare products pretty closely. Sizes were pretty consistent save for a few examples. For instance, this product was labeled as a 1/4" to 1/8" reducer but measured 7mm and 4mm respectively (as opposed to 6mm and 3mm), meaning not all hardware sold as 1/8-inch is actually 1/8th inch.

https://www.amazon.com/gp/product/B07TCY92BS/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

 

Edited September 5, 2020 by D.A.

[D.A.]

In general, I find it works best when the female parts (hoses, rubber caps) have a slightly smaller inner diameter (e.g., 3.5mm) than the outer diameter on the male parts (brass fittings, TB nipples, sensor nipple) (e.g., 4mm), although I did go with 4mm [5/32-inch] vacuum caps on this project.

Edited September 7, 2020 by D.A.

[Jerzee]

Nice write up, and photos, was looking to do something similar. Thank you for providing links for the parts too. Curious about what you used for the end caps? Was looking at Black Vinyl End Cap Screw Thread Protector Rubber Caps https://www.ebay.com/itm/20pcs-3-5mm-Round-Black-Vinyl-End-Cap-Screw-Thread-Protector-Rubber-Caps/233704938549?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

but not sure if it is appropriate / safe, or will give a good seal? Suggestions welcome.

Thank you,

Jerry

[D.A.]

Hey @Jerzee!

I should have been more specific as it pertains to the vacuum caps I used.

The narrowest sections of the 4mm barbed brass tees and elbow couplers measure 4mm but the raised ridges (meaning the barbs themselves) measure 4.4mm. When connecting this hardware to 3.5mm hose, the connection is very tight. So tight, in fact, it's hard to separate the two. But that's ideal for most of the connections you'll make.

When it comes to the caps covering the ports where the manometer hoses connect when syncing throttle bodies, I wanted a slightly less tight connection so I used 4mm (5/32-inch) rubber caps rather than 3.5mm (9/64-inch) caps. The resulting connection is loose enough the caps can easily be pried off without any tools but tight enough they won't pop off by themselves.

When searching the web I did not see any 3.5mm rubber automotive caps – plus I wasn't sure which size caps I would need until I got into the job – so I bought a multi-pack to go along with the miscellaneous collection of caps I already had.

As a precaution I bought some hose clamps for the caps but thus far I have not needed them because the 4mm elbow-to-4mm rubber cap is plenty secure on its own. That being said, if you go with 4mm rubber caps and want the added security of hose clamps, I got the best fit using 7mm clamps. 8mm clamps also worked – and are probably the correct size technically since the 4mm inner diameter caps have an outer diameter of 8.2mm – but the 7mm clamps seemed more secure.

In regards to the 3.5mm caps you found on eBay: Those don't appear to be automotive-grade items designed for an under-hood heat environment. They may work fine but I personally would not take a chance on them.

 

Link to the rubber vacuum caps I bought (I used the 5/32-inch size since that's equivalent to 4mm):

https://www.amazon.com/gp/product/B008DZSZK6/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

 

These are the hose clamps I used. There were quite a few variety packs available, which would have been more flexible and cost effective, but there were a lot of bad reviews for them. The Uxcell clamps below got better reviews but were not available in multi-packs:

https://www.amazon.com/gp/product/B07TPL594N/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B07TK7ZVTG/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

 

 

Edited September 7, 2020 by D.A.

[Jerzee]

Hey @D.A.

      Thank you for the quick reply and great information. I will explore those links, and think I have what I need to complete the project. I assume you cut your t-fitting into the original vacuum line on the bike, and clamped the ends of the hose onto the t fitting on the one side, and simply attached and extension piece of vacuum line on the 'capped off' location on the other side, cable tied everything onto the frame, and are ready to sync. Thanks again for the clear pictures, great write up and links to the parts you used in this mod. 

Jerry

[D.A.]

12 hours ago, Jerzee said:

... I assume you cut your t-fitting into the original vacuum line on the bike, and clamped the ends of the hose onto the t fitting on the one side, and simply attached and extension piece of vacuum line on the 'capped off' location on the other side, cable tied everything onto the frame, and are ready to sync. ...

That is correct. I spliced the tee-fitting into the OEM vacuum line on the left side of the bike and ran the new portion of hose through fairing mount. This still left plenty of room behind the grommet for the stud on the fairing. And on the right side of the bike I connected a piece of 3.5mm hose directly to the right throttle body nipple and ran that hose up through the right side fairing mount.

Only difference is on the right side of the bike, there are a lot more cables and hoses crowding the area so I routed the 3.5mm hose through one of the holes in the fairing mount in a slightly different way than on the left side. Once you get in there you'll see what I mean and can route the hoses any way you see fit. There are a few different ways you can route them and all will work fine.

[D.A.]

 

For those who haven't synced their own throttle bodies and are interested in doing so, here are some photos of the process. It's pretty easy – especially if you've taken the time to install remote access tubes as illustrated in the postings above.

Start by removing the fairings (a.k.a. tank covers), removing the long bolt that attaches the front of the fuel tank to the frame and removing the front-most rear bolt on the back of the tank, then tilt the tank back and insert a piece of 1 x 2" wood to support it. I also use bungee cords to lightly hold the tank in place so it can’t move when the engine is running:

 

The wood provides just enough clearance to get a long flathead screwdriver onto the right throttle body screw. Please note: This is the only screw you should mess with when syncing the TBs.

 

Next, set up the manometer on the left side of the bike. I use and highly recommend the Morgan Carbtune Pro 4 – https://www.carbtune.com/carbdtls.html 
You can get the best price on it directly from the UK manufacturer but it’s also available on eBay, Amazon, etc.

 

Fans at the door suck exhaust fumes out of the garage:

... while a fan at the entrance blows fresh, cool air onto the radiator and engine.

 

Start by keeping one side of the throttle body capped and connecting a hose and Tee to the other side. Doing this allows you to run the same vacuum source into two ports on the manometer to make sure they both display the same level.

 

Once you verify the levels you can remove the Tee and connect the manometer hoses to the two throttle body ports – or in my case the frame-mounted remote ports:

 

Start the engine and let it idle. When the bike gets up to operating temperature, adjust the screw on the right side of the throttle body as necessary until the two manometer levels match. Then twist the throttle grip a few times to rev the engine. This will cause the levels to fluctuate wildly. Wait a minute or so for the meters to level out again. If they match, great! If not, adjust and rev again as necessary. Repeat the process until they stay matched after revving:

 

When finished, be sure to re-cap the vacuum ports otherwise the engine will not run right:

 

Edited September 9, 2020 by D.A.

[Jerzee]

@D.A. Thanks again for the clear write up, and useful photos. I think that even I can figure this out now.

Jerry

[Pursuvant]

On 9/2/2020 at 11:23 AM, mossrider said:

I've never synced my tb's. I wedge the throttle plates wide open and set the cables and throttle tube to match. Go zoom.

But MossR, then an old fart like me, would not get the chance to get out the old "Carbtune" circa (about 1980, I'm not even sure) and have the fun of screwing around with doing it the textbook way. I'm kinda curious, does my chemo wrecked brain still have enough go juice to work it all out on the new configuration of fuel injected throttle bodies? With D.A and DewMan showing the way I just got to give this a shot. Note the Carbtune is surprising appearing to operate smoothly, the weights are gliding smooth baby smooth. Can't believe it, hats off to the folks who made this thing so long, long ago when I had real hair

And if I screw it up or give it up, I'll fall right back to your strategy MossRider

Carbtune 1980 bought so I could tune a GPZ550 that was the hot ride back then, it introduced the whole line of ninja motos and the whole middleweight class of 600's that appeared shortly after...

Edited September 8, 2020 by Pursuvant

[Pursuvant]

On 9/5/2020 at 2:12 AM, D.A. said:

Hola @DewMan:

Here's how I did my port relocate:

 

D.A and DewMan,

You guys got the most interesting post I've seen here in a long time, you really got my interest in what you're up to. I thought about throttle syncing but my bikes still too new, something I was saving for the off season tuneup stuff.

Great post, great idea, and incredible detail and explanation, thank you both, sirs!

[mossrider]

Just now, Pursuvant said:

But MossR, then an old fart like me, would not get the chance to get out the old "Carbtune" 

And if I screw it up or give it up, I'll fall right back to your strategy

Truth be told I dug out my mangynometer too and are gonna give this a whirl.  It's been a looong tyme. 

[Spatt]

On 9/2/2020 at 12:23 PM, mossrider said:

I've never synced my tb's. I wedge the throttle plates wide open and set the cables and throttle tube to match. Go zoom.

That doesn’t balance anything. Balancing them insures they are pulling the same amount of air. Especially if you bore them, they’re almost 100% out of sync.

[mossrider]

7 hours ago, Spatt said:

That doesn’t balance anything. Balancing them insures they are pulling the same amount of air. Especially if you bore them, they’re almost 100% out of sync.

Right. I never said it does, just relayed what I have done. I did check it once years ago but they've been forgotten and I have no idea where they're at now. That's why it says above that I'm gonna get this done.

[D.A.]

8 hours ago, Spatt said:

... Especially if you bore them, they’re almost 100% out of sync.

What does 100% out of sync mean in the context of throttle bodies? Is that like one throttle body pulling 22 cmHg and the other pulling -22 cmHg (a.k.a. pushing 22 cmHg)? Or one pulling 22 and the other pulling 0?

[mossrider]

15 minutes ago, D.A. said:

What does 100% out of sync mean in the context of throttle bodies? Is that like one throttle body pulling 22 cmHg and the other pulling -22 cmHg (a.k.a. pushing 22 cmHg)? Or one pulling 22 and the other pulling 0?

Matt just meant they're almost guaranteed to be out of sync.

[mossrider]

Well, I dug the ole Motion Pro out and had at it. Dead nuts on. Could just as easily been off too.

Good thing I did as it gave me an excuse to change plugs and check a few things that have been overlooked. Cost - $0, peace of mind priceless.