Throttle Body Synch Gauge

[ChUcK]

1st post, 1st sportbike, how is everybody doing today? Good times.

I was wondering if anyone had some extra knowledge about the gauge used for synchronizing the throttle bodies. I found a couple of DIY gauge how-to's, but they were for Vtwins.

My question is- are all four mercury-filled lines connected at the base? I assume so, but I am not going to construct my own synch gauge without knowing this for sure. My plan is to make one with a small valve on the base that can isolate two of the lines, thereby allowing the gauge to be used for my buddy's 2-cyl SV650 as well.

Anybody ever make their own tool for this? I am looking to keep this on the cheap and have no interest in purchasing the gauge if it really is just four connected columns of fluid. My 09 is just under 600 miles and I want to keep up on the scheduled maintenance in the Omanual.

Thanks for your help, hopefully I can be of similar assistance to you in the future!

ChUcK

 

[stevesnj]

http://www.600riders.com/forum/garage-mechanical-help/9453-throttle-body-synchronization.html

 

[TownsendsFJR1300]

I invested in a Morgan Carbtune syncronizer. There are no fluids to spill or suck into your engine (not good) and it is extremly well made. It uses Stainless Steel rods instead of fluid. Its paid for itself many times over syncing different bikes and is fool proof. BTW, I've also used it on my 150 HP Yamaha 4 stroke outboard engine which pulls much more vacuum (If I had fluid in there, it would have sucked it into the engine).

I had to order from the UK but it was less than $90 shipped to my door...A sync at a shop will cost you well over $100. Excellent unit IMHO

I don't think anyone's using mercury anymore for health reasons.

Each line / cylinder in the gauge is NOT CONNECTED to each other, it would defeat the purpose of the tool. The amount of liquids have to be dead on to be accurate.. Your measuring the vacuum of each cylinder against each other and adjusting accordingly.

Good luck

 

[ChUcK]

I have searched essentially every thread that mentions this procedure, and I've read all the testimonials for store-bought products already...

If the four tubes of liquid are not connected, then it seems like a pretty easy tool to make yourself. My plan is to get a bunch of thin, clear, plastic hose and mount four of them along a 2x4 or a yardstick. Fill them with the densest liquid I can find OTC, and go with it.

I understand that this is not a quantitative tool, I'm just looking to qualitatively adjust the throttle bodies so they are all equal relative to each other. I can hook up a pressure gauge to check actual vacuum values at another time. As far as I can tell you just have to fill four tubes to equal heights of fluid and connect them to your bike (maybe with four traps to ensure nothing gets sucked into the cylinders) and then perform the sync procedure. Am I missing any other important details about these gauges?

Thanks for the responses!

 

[ChUcK]

Each line / cylinder in the gauge is NOT CONNECTED to each other, it would defeat the purpose of the tool.

You sure about that? Or are you just guessing?

 

[TownsendsFJR1300]

You sure about that? Or are you just guessing?

Yes I am. If I was not sure, I would say so...

It would defeat the purpose tying the gauge or cylinders together.

Your trying to find what the vacuum is in each cylinder and balance them so one's not pulling harder than another. Tying them together would defeat that purpose...

It should be noted that the Carbtune uses restrictors in each hose to keep the vacuum steadier. Each long hose is cut, the restrictor placed in-line and a short (approx 5") of the remaining hose re-attached...

 

[ChUcK]

Hmmm, I talked to some of the physics grad students at my school and it appears that it doesn't matter if the columns are interconnected or not, only that you must make sure to get the initial fluid amounts exactly equal if they are not coming off a single reservoir.

All agreed that even if the difference is too small to notice, the interconnected tool would be more accurate by default. If the fluid levels can be balanced when interconnected, then the vacuums are exactly equal. With the separate columns, variations in the exact amount of fluid in each reservoir will cause proportional inaccuracies. I suppose filling them by weight would be better than by eyeballed volume, if you had a scale that could read down to tenths or hundredths of grams.



I don't argue that the store-bought is probably better for most DIY mechanics, because you know that the thing has been tested and retested, and proven to work for our bikes.

I'm going the other route, because I believe that I can't screw up as long as I stick to proven fluid dynamic concepts, and ensure that the build is sturdy and leak-free. You can't argue with physics- that's why they call them laws, I suppose.

 

[TownsendsFJR1300]

I stand corrected re the homemade manometer. The below link shows some different styles homemade from an FJR forum:

Tools for TBSync - FJRForum

The Carb Mate that I use is not connected but I gather just use the weight of the SS rods inside the unit (instead of fluid).

 

[ChUcK]

The prototype gauge worked as well as I hoped. I installed some "oil traps" which are simply a wide spot of tube with some wadded up paper towel inside, but they ended up just being extra fluff that extended the time it took for the gauge to respond to adjustments.

Here's the gauge in action. Yes, I know it's a fz6r- I needed tech support to get on the fz6r forums and I ended up here. This thread was started before I realized I was on the wrong forum!

[ame=http://www.youtube.com/watch?v=_oRJxPOXD50]YouTube - Prototype TB Sync Gauge[/ame]

[ame=http://www.youtube.com/watch?v=Do5b3-l6TG0]YouTube - Sync Progress[/ame]

If anyone wants to build their own gauge I can tell you how to do it on the cheap. I could have built this gauge for 5 bucks, but I added on stuff I already owned. The extra cost of that stuff is probably 20 more dollars.